Walnuts are edible seeds, the stone fruit of the walnut (genus: Juglans) tree. The seed is enclosed in hard husk, and both the husk and the shell are generally discarded in order to market shelled nuts. Walnuts are a popular snack and ingredient around the world.
Walnut Market Size
Global Walnut Production
According to Food and Agriculture Organization of the United Nations, the world production of walnuts in 2022 was 3.874 million tons, with production led by China, the U.S., Iran, Türkiye, and Mexico. The top ten producing countries in the world produce approximately 89% of the global walnut supply. In 2022, the global walnut crop occupied approximately 1,247,937 hectares.
Country | Production, 2022 (tons) | Area Harvested, 2022 (hectares) | Yield, 2022 (100 g/ha) | Percent of global total |
China | 1,400,000 | 356,656 | 3,925.4 | 36% |
United States | 682,200 | 161,876 | 4,214.3 | 18% |
Iran | 355039.94 | 52,150 | 6,808.1 | 9% |
Türkiye | 335000 | 166,495 | 2,012.1 | 9% |
Mexico | 176892.92 | 117,000 | 1,511.9 | 5% |
Chile | 153000 | 46,232 | 3,309.4 | 4% |
Burkina Faso | 134955.37 | 90,889 | 1,484.8 | 3% |
Ukraine | 107660 | 12,900 | 8,345.7 | 3% |
Greece | 60680 | 16,710 | 3,631.4 | 2% |
Romania | 53400 | 2,830 | 18,869.3 | 1% |
Source: FAOSTAT, find the data we pulled here.
The US Department of Agriculture’s Foreign Ag Service provides additional accounting of global walnut production, which records production data for the 2023/2024 crop year. This data is collected by USDA independent of the UN Food and Ag Organization.
By all counts, China is by far the dominant producer of walnuts globally, followed by the U.S. and then other Asian, Latin American, and European producers. By region, almost 60% of all walnuts are grown in Asia. The long term trend in walnut production has been upward, though year to year weather and market impacts have lent some volatility to this trend.
When it comes to demand, China, the EU, the U.S., and Turkey combine to consumer around 75% of the world’s walnuts, though the Middle East and India are increasing their share. The U.S. is the leading exporter of walnuts. There does seem to be some evidence of plateauing demand for walnuts globally, however that comes at the end of a long period of tremendous demand growth.
Though global demand has steadied, increased supply and other pressures, especially in the U.S., led to a long period of price deflation for walnut growers. Though prices and total global acreage were up in 2023 thanks to some supply relief, the long term damage of depressed prices in places like Chile led some analysts to conclude that there may be decreasing production going forward outside the U.S., and reduced exports from China.
These hurdles, in addition to others around regulation, cost, competition and logistical hurdles will likely slow the overall growth of global walnut production substantially going forward. Instead, growers will likely look to improve quality and better manage profitability per acre, rather than look to expansion for growth.
U.S. Walnut Production
California producers grow approximately a billion pounds of walnuts per year, accounting 99% of American production. California is the only state in the US with meaningful commercial walnut production. According to the USDA National Ag Statistic Service, in 2023, California farms produced about 824,000 tons of walnuts on approximately 385,000 bearing acres, with an average yield per acre of 2.14 tons. The U.S. crop in 2023 was marketed at an average (in-shell) price of $840/ton, down nearly 50% since 2021, but up slightly over 2022. The total U.S. walnut crop in 2023 was worth $692,160,000. The California walnut industry includes more than 4,000 growers and fewer than 100 handlers (brokers, packers, shippers, etc.). The majority of Californian walnut farms operate fewer than 500 acres.
Nine counties within the state of California: Butte, Glenn, Kings, San Joaquin, Stanislaus, Sutter, Tehama, Tulare, and Yuba accounted for the majority of walnut bearing acreage, though in 2023 and 2024, walnut production occurred in 21 counties in total, mainly in the Central Valley.
Due in part to dramatic price declines in recent years, walnut plantings in the U.S. have fallen precipitously, and are likely to continue to do so. The current fall in plantings represents the longest run in consecutive year declines since 1951.
These price declines are driven by a number of factors; including stagnant domestic walnut consumption, the U.S.’s declining share of global walnut exports (from 62% in 2012 to 42% in 2022), external factors like tariffs and COVID-19 disruptions, a growing market preference for one particular variety (Chandler) the makes marketing other varieties from mature groves more difficult, and high levels of annual production keeping the supply high.
The U.S. walnut industry is renewing its focus as yet untapped export markets and in shifting consumer perspectives around the nut— aiming to reposition it as a healthy snack food rather than an ingredient in the baking aisle. However, these efforts are unlikely to provide short-term relief to U.S. growers facing difficult market conditions. That relief is more likely to come through walnut acreage retirement, which is on the rise, and many are hopeful this trend will help reduce production and overall supply in the years to come. Production is predicted to be down for the 2024 crop year, on a per-tree basis, yields are expected to be at a 24-year low.
Varietals
There are about 40 varieties of walnuts produced in California, while just six varieties make up about 85% of all plantings. All commercial walnut varieties grown in California are English (formerly Persian) type walnuts, as opposed to black walnuts. Black walnuts have a bolder flavor compared to the milder English types, but their shells are thick and tough to crack, and thus are not common in commercial production.
Top Walnut Varieties in the US
The Chandler walnut is by far the most popular and important variety that’s planted in California and worldwide, and accounts for nearly half of acreage in the state. The variety is highly fruitful, extremely vigorous, and has relatively few pest problems.
Most importantly however, the kernels of Chandler walnuts are of a particularly high quality. They are light colored and easily removed from the shell, which has made the most in-demand walnut variety in the world. One of the few downsides of the variety is that it is harvested relatively late as compared to other varieties. This has not limited the demand for Chandler plantings, and in fact, the prevalence of Chandler’s in the global market has made it difficult for growers with older orchards in other varieties to compete.
According to USDA NASS, there were 147,784 acres of Chandler trees standing in the U.S. in 2021.
The Tulare walnut is the second most commonly planted variety in California. It yields a significant harvest of large, light colored nuts with semi-soft shells, making them popular for in-shell markets. Compared to the Chandler, it is a mid-season variety.
According to USDA NASS, there were 31,676 acres of Tulare walnut trees standing in the U.S. in 2021.
The Howard walnut is a top three variety in California. It is a thin and light colored shelled nut know for it’s flavorful and large kernel. Compared to the Chandler, it is also a midseason variety. The Howard tree is also smaller than Chandler varieties. Howards are known for late-leafing and consistent, bountiful production. This makes Howard a good candidate for high-density production systems.
According to USDA NASS, there were 30,108 acres of Howard walnut trees standing in the U.S. in 2021.
The Hartley walnut is still a common walnut variety in California, but it’s popularity is not growing. It is a thin shelled nut know for it’s sweet, high quality kernel. It is an old and popular variety for fresh eating applications. It is both somewhat resistant to blight and coddling moth and a consistent producers over the life of the orchard. Compared to the Chandler, it is also an earlier blooming variety. As a product, Harley’s are a popular in-shell variety due to the quality of the seal and ease of cracking.
According to USDA NASS, there were 26,615 acres of Hartley walnut trees standing in the U.S. in 2021.
The Serr walnut was once a very popular walnut variety, known for it’s resilience to hot climates, marginal soils, and sunburn. In recent decades, however, growers in California have largely stopped planting this variety. The Serr variety yields large nuts with a fair seal, but a major limitation is that the Serr trees are large and require significant spacing within the orchard. Compared to the Chandler, it is also an early to mid-season variety.
According to USDA NASS, there were 10,266 acres of Serr walnut trees standing in the U.S. in 2021.
Similar to the Serr, the Vina walnut variety has been a popular variety in California, but has not grown in popularity over the last two decades. Vina trees yield medium sized nuts with good shell seals. Vina trees tend to be small and relatively compact, with moderate vigor and high productivity. Compared to the Chandler, Vina is a mid-season variety.
According to USDA NASS, there were 9,192 acres of Vina walnut trees standing in the U.S. in 2021.
Other common walnut varieties include; Payne, Franquette, Chico, Eureka, Ashley, Sunland, Tehama, and Cisco. Each variety has its own benefits and drawbacks in particular markets and when paired with conditions on a given farm. Some of these varieties are also commonly planted as pollinator plants for the varieties above.
Forde, Gillet, and Sexton are relatively new walnut varieties that are still being explored in California, though they were released from their breeding program in 2004.
Newer varieties, including UC Wolfskill (2021) are still being bred and released, with new varieties often combining the benefits of existing varieties to refine a growers choice of traits like harvest timing, kernel color, shell thickness, etc. New varieties are always interesting for walnut growers to explore, however, given that the lifespan of a typical walnut orchard is around 35 years, it is often not possible for growers to quickly and easily experiment with or transition into new varieties.
Addressable Market for Walnut Technologies
Market
Based on multiple analyses, the global walnut market is likely to grow to between $11.25 and $14.7 billion USD by 2030 from a a 2023 value of around $7.9 billion (a CGAR of between 5.15% and 9.39%). Based on the Industry Arc analysis, the global walnut product market could be worth as much as $8.156 billion in 2020 ($9.26 billion in 2025) and will grow to about $11.814 billion (at a CAGR of 5.44%) by 2027.
The global market for walnuts is facing positive headwinds as consumers have a good perception of their positive health benefits (especially as a whole food), but also as an ingredient in processed foods, especially alternative milks, oils, and flours. Walnuts are also an increasingly attractive ingredient in some cosmetics and personal care items. Walnuts also have applications in pharmaceutical and household market segments. Walnuts are also a globally accepted ingredient with applications in both sweet and savory dishes and snacks around the world. In fact, walnuts are globally the most consumed tree nut, nearly doubling world almond consumption.
Though walnuts are not as popular in the U.S. as almonds, and have struggled in recent years due to the market center largely around walnut as a baking ingredient, they remain one of the most consumed tree nuts.
On the production side, especially in California, challenges continue to mount—from water availability to increased growing costs, which has largely caused production of walnuts in the state to level off. According to the USDA’s National Agriculture Statistics Service, bearing walnut acreage in California is down, which corresponds with reports that growers have responded to production pressures in part by moving away from the crop. In some of the last several years, walnut growers have lost between $500 and $1500 per acre. This has mean that U.S. walnut exports have fallen as well, from 62% of global exports in 2012 to 42% in 2023, due also to increased acreage in China, quality issues, and lost market share related to tariff disputes in the late 2010s.
The true addressable market for walnut harvest and management technologies will be approximately equal to the cost of labor needed to manage and harvest walnuts. So to determine the value of a specific technology to the sector, it’s necessary to understand the costs associated with walnut production.
The Anatomy of a Walnut Farm
Grower Challenges: Production
Successful walnut growers manage a complex production system that takes careful and continuous management over a variety of plant life-stages. From the origination of an walnut production business, the planning process until the first harvest can be between 4 to 7 years, and additional time is required for trees to reach full productive maturity. A commercial walnut orchard generally only remains productive for approximately 35 years before it is removed and replanted. Managing production and cash flow over that time horizon is often a challenge.
- There are many factors to consider when planning and establishing a walnut orchard including: soil type, pest and disease history, drainage, water access and quality, and local weather. Soil testing is a critical first step in determining whether a given acre is well-suited to walnut production.
- In the year prior to planting, the orchard’s soil must also be prepared. If the site was previously planted to walnuts, the soil must be ripped up to four feet deep to remove hardpan and old roots. Then, additional discing to breakup clods may be required, and then laser leveling to eliminate standing water. The soil should then be fumigated, and tree rows formed.
- Water access may well be the primary concern in most of the Californian walnut growing regions— with a chief question being whether irrigation water is to be drawn from surface sources or from a well. Both options have their benefits and drawbacks; namely, surface water can be less expensive to pump, but can be cut off when water is not available during periods of drought. Conversely, growers generally have more access to and control over wells, though there are risks related to land subsidence due to over-pumping and the possibility of the well drying up.
- After water access is established, the irrigation system should be planned before planting. Flood irrigated walnut orchards are still common in California among older orchards, though as water becomes increasingly scarce and costly, most new groves take advantage of alternatives like micro-sprinkler, drip (surface or subsurface) or full coverage set sprinkler systems. If the selected irrigation system requires land alterations (furrowing, subsurface installation, etc.) that work will likely need to be completed prior to planting.
- A grower has some latitude to decide how an orchard is laid in terms of design and tree density, however there are two dominant planting systems in California. Factors such as management style, variety, site vigor, irrigation method, and soil type will inform the decision. The spacing between trees within a row and between trees across a row is similarly determined, though harvest method, equipment size, and other cultural practices are also determining factors.
- The first system involves a wide spacing, 25 - 30 ft between trees and between rows. This encourages trees to develop expansive canopies to help maximize production. However, this method does not provide early returns due to the fact that it takes trees longer to occupy all the available space.
- The other common design involves closer plantings, approximately 22 ft between trees and 15 ft between rows. This more densely planted orchard lends itself to greater early and overall returns, though also additional costs due to the higher number of trees per acre. This system, called a hedgerow design, is also easier to prune with a mechanical hedging machines, rather than by hand.
- Though it was common in the past for growers to carefully select a walnut variety specifically suited to their soil, local climate, and management conditions, market factors today and the high demand for the Chandler variety means that most often, the Chandler variety will be the one selected for planting in new California orchards.
- Growers are more likely to vary their selection of root stock, which is most often a variety of black walnut, which tends to be more hardy and pest-resistant than english walnut varieties. Paradox rootstocks are typical in the San Joaquin Valley today.
- One factor that differentiates walnuts from other nut trees in California is the high cost/limited availability of grafted finished trees. Therefore many growers will establish an orchard by planting potted rootstock in one season and then grafting the trees the following year. This process adds an additional year until the orchard’s first viable harvest, and extra labor and/or service expenses.
- Planting occurs in spring, and involves marking planting sites, digging the hole, inserting the plant and then staking the tree. After trees are inserted, they are painted white to prevent sunburn and a tree protector is put around the base to protect from herbicide damage.
- 4% of trees will die annually, and will need to be replanted the following year.
- The aim of training in the early years of the tree’s life is to develop good structural strength in primary branches (to support hardy fruit loads), to guide the tree to fill its available space in the orchard, and to manage growth to encourage early production. Training involves both securing the tree to a stake during it’s early years of development and pruning. Successful training between years 1 and 6 are critical to ensuring a productive and healthy grove over the life of the trees.
- Pruning in the walnut orchard is done either by hand or by a hedging machine, and serves to control tree height and direct growth as well as to remove dead and diseased wood. Pruning also changes resource and hormone balance within the tree, though the direct physiological response depends on the timing and type of cut. Generally pruning is carried out between October and January, while the tree is dormant.
- Pruning and training are best carried out by pruners with knowledge and experience. Each tree must be pruned in a relatively customized way to promote tree health and vigor.
- Pruning and training activities begin immediately after planting. In the first year, the leader (a shoot selected as trunk) should be allowed to grow unheaded, meaning the tree should not be cut at the top to encourage lateral growth. Any shoots should be removed. Leaving the tree unheaded has not only shown to lead to earlier yields and larger trees overall, it also reduces labor cost related to pruning and training. However, trees should not be allowed to grow beyond 12 ft in height.
- In years two and three, limbs below 4-5 ft should be removed (or 3-4 ft in hedgerow systems). No additional pruning should be required. Unpruned trees tend to grow branches naturally well-spaced along the trunk at wide angles.
- Alternatively, growers may prefer a more traditional and costly pruning method which involves heading the trunk between 7 and 8 ft at the first dormant pruning. This method requires additional heading cuts in the second and third year, and generally requires more pruning/training labor.
- Tree water usage depends on the tree’s age, size, species, climate, and soil type. But other factors, including the energy cost of pumping water, the cost of water itself, a grower’s irrigation strategy, and any rules or restrictions put in place by local water districts will influence the amount of water that growers apply in the walnut orchard.
- Though some essential water each year will come from rainfall and existing soil moisture, walnut orchards in California will still likely need to irrigated about once per week from April through October.
- In some areas, growers will use their microsprinkler irrigation system as a form of frost protection, generally in February or March. This involves the application of irrigation water prior to and during frost events, which can help prevent damage to the trees. The regularity and amount will likely vary year to year.
- There are multiple kinds of standard irrigation systems in use in California, though there is certainly a growing preference for the most water-efficient systems. These include permanent set sprinklers, microsprinklers, and surface and subsurface drip.
- Each irrigation system has its own benefits and drawbacks. While microsprinkler systems can help save water over some alternatives, they can also encourage bigger root volume. Drip systems can reduce soil water evaporation, but are not effective for frost protection. The irrigation system should be carefully matched to the conditions and management preferences of an individual orchard/orchard manager.
- Salinity management is a key issue for walnut growers, due to the tendency of dissolved salts (sodium, chloride, and boron) to concentrate in irrigation water, which is then transferred to soils. Exposure to too much salt can lead to toxicity in walnut trees, which can cause root dieback and leaf loss, even when utilizing hardier (and more salt resilient) black walnut rootstock. This problem is particularly pronounced in shallow or poorly drained the soils, and the Chandler variety is particularly sensitive to this stressor.
- Modern irrigation management generally involves water budgeting, soil water measurement (especially through the use of probes), and smartphone apps, and growers will increasingly hire specialized irrigation managers to plan and manage water allotments, scheduling, and quantity allocations during times of shortage. Irrigation scheduling and optimization will be highly differentiated between operations.
- Unlike almonds, walnut trees are effectively wind pollinated, and therefore do not require bees or other pollinators to ensure pollination.
- Fertilizer and soil amendments are applied in most orchards annually, through a combination of drip line or through foliar application. Fertilization rates vary depending on a variety of factors, including soil type. Fertilization also varies more in the first six years of the orchards life than it is likely to during the more productive later years.
- Leaf and tissue samples are regularly taken for nutritional analysis starting during the fourth year of the tree’s life.
- Granular nitrogen will likely need to be applied during the first two years, after which liquid fertilizer (i.e. UAN) can be banded throughout the orchard via the irrigation system. Potassium in the form of sulfate of potash (SOP) is commonly applied in the fall. Both key nutrients should be applied in accordance with leaf/tissue sample results and/or estimations based on previous crop years (and resulting nutrient outflows).
- There are many pests, including insects, weeds, diseases, and invertebrates that walnut growers will have to contend without throughout an ordinary growing season. Read on for more on the products and practices growers use to combat these threats. For more on the pests themselves and how they effect the crop, see Considerations for Pests and Diseases below.
- Managing the orchard floor is critical for walnut growers because walnuts are retrieved from the ground. There are many strategies to control weeds on the orchard floor, including mechanical mowing, winter and summer strip spraying. Foliar herbicides (before planting) and pre-emergence herbicides are commonly applied early in the year.
- Insects in the orchard are managed through insecticide or biological treatments, both after planting and after the orchard reaches its productive years. These might be applied either through chemigation (through the irrigation system) or by ATV mounted spryer, spot sprayer, or broadcast by a tractor-pulled air-blast sprayer. A few key insects and mites that California growers deal with include:
- Aphids and mites, which are treated for annually.
- Codling moth, which should be tracked through the use of traps. A treatment with a product like Altacor mid-year is usually effective.
- Navel Orangeworm can be treated both with chemical applications and prevented through winter sanitation activities (like mowing and disking).
- Scale can be treated with an annual application if necessary, starting after the orchard reaches its first harvest.
- Walnut husk fly should be monitored with traps as well, and treated when populations become problematic with multiple spray applications.
- Nematodes are primarily treated through pre-plant soil fumigation, though this may not always be necessary.
- Disease in the orchard is managed with brand name applications designed to address specific diseases or fungus. Walnut blight and Botryosphaeria canker and blight in particular are likely to require treatment, depending on local conditions.
- Vertebrates are controlled with poisoned bait (specifically for gophers and ground squirrels), or with preventative physical coverings, like tree guards to prevent young trees from being predated or damaged by deer.
- Growers will likely hire a Pest Control Advisor (PCA) or a crop consultant to monitor their orchard for pests, nutritional deficiencies, and other agronomic problems. This expert will likely also recommend products and practices tailored to an orchard’s specific needs.
Most walnut orchards are harvested with mechanical shakers, and then mechanically swept, picked up, and hauled to the huller. This process might be done by the farm itself with owned equipment and hired labor, or it might be contracted out to a custom walnut harvester. Labor is required to operate the equipment, but also to hand rake nuts that are missed by the sweeper and to do other support tasks.
- Walnuts harvest generally runs from late-August to November, depending on geography, location, and climatic factors. Walnuts are harvested when a high percentage of green hulls start to split, making it possible for the inshell walnut to be removed. Hull splitting (and then nuts falling naturally to the ground) can be hastened by applying compounds like ethephon.
- The harvest process begins by sweeping the orchard floor clean, then a harvester with a shaker head attaches to an individual tree trunk. The harvester then shakes the trunk, causing the walnuts to fall from the tree onto the ground. From there, nuts are swept into the windrows and a pickup machine then gathers the nuts and loads them to be hauled out of the orchard. The amount of time nuts spend on the ground should be minimized. The outer green husk will be removed by the huller, and the nut will be cleaned, dried, and stored in an outside facility.
- Hulling and drying costs are generally charged per-pound of dry-weight. Custom harvesting (hiring out the task of harvesting), is generally charged by the hour, acre, or yield and includes harvest, hauling, hulling, and drying.
- One acre of walnuts is likely to yield 4,000 - 6,000 pounds of walnuts once it’s reached full maturity (usually after 7 years), depending on the variety and other factors. However, in 2024, average U.S. yield is expected to be closer to 2,700 pound per acre, or 44 pounds per tree, significantly lower than previous years, likely as a result of extreme heat and drought during the growing season.
- Walnuts are marketed both inshell and shelled, but are stored inshell to preserve their shelf life.
- The overall size and scale of the farming operation, and what (if any) other crops/varieties the farmer grows. Number of acres and how vertically integrated a walnut business is will have significant impacts on how the management decisions are made within the orchard.
- Whether the land is owned or rented by the grower.
- Infrastructure availability (road access, irrigation systems, building locations, etc.).
- Access to labor and equipment.
Grower Challenges: Economics
Common Walnut Farm Business Model
Walnut growers generally sell in-shell almonds to processors, wholesalers, retailers, food manufacturers, and other buyers, or in rare cases, sell in-shell nuts directly or process nuts themselves and sell ingredients (whole, chopped, or crushed nuts that may also be toasted, roasted, pickled, candied, raw, etc.) or finished products (snack mixes, oil, etc.). If unshelled or otherwise processed almonds are sold, excess casing (hulls and shells) can provide a small additional revenue stream, as they are sometimes used in low-abrasive, less-toxic cleaning/blasting applications, or as an ingredient in cat litter.
Therefore, the annual revenue potential of a walnut orchard business will depend on the yields achieved, the quality of the product, the price, and the distribution networks they are able to access. A farm’s overall success will therefore also depend on the walnut growers ability to manage other costs such as labor, fertilizer, pest management, land costs (including land rent if leasing), as well as the potential for unexpected weather or market conditions.
Growers sell walnuts in the U.S. by the pound or ton. The work of shelling nuts, as well as cleaning and drying, sizing, sorting, grading, and storage in bulk containers until sold, shipped, or further processed, is done by a sheller/huller. Some farms are both growers and processors/marketers. Typically, if the farm does not own the shelling/hulling operation, the huller will buy the walnuts from the farmer at the time of delivery, and the responsibility and benefits of additional processing will transfer to the sheller/huller.
Though in-shell walnuts are generally stored in open warehouses or in bins until further processed, further packaging for sale is more responsive to customer demands. iIn-shell walnuts are general packed in large sacks, then palletized. Shelled walnuts might be packaged in cartons lined with parchment paper, while more highly processed walnuts (crushed, candied, etc.) are packed in plastic containers or bags to protect against moisture and oxygen and preserve shelf-life. 75% of all walnuts are sold shelled.
There are a few different channels that growers commonly use to deliver walnuts to market. The most common is to sell directly to the sheller/huller upon delivery, with the price per unit determined base on quality and market conditions. Alternatively, walnuts can be sold directly to consumers through on-farm sales or farm stands, though a very small amount of the total US crop is moved in this fashion. Finally, vertically integrated operations the own their own processing facilities will be able store, process, and market nuts directly to food buyers, wholesalers, and other potential customers.
The business model for walnut production requires significant upfront investment that must be earned back over the course of an orchard’s productive life. Though trees will start producing nuts as early as the third or fourth year, they often don’t come into their productive prime until after their seventh or eighth season. As the orchard ages, yield and quality generally decline and the orchard will need to be removed and replaced after about 30 years. There is an expectation that as much as 1% of trees will need to be replaced annually.
The yield of the average acre of walnuts can vary significantly based on a number of factors, especially variety and geography. Many factors also determine the actual price per unit of walnuts a given grower receives (though the average in 2022 was $0.25/pound USD). Because of the difficulty of determining these two factors, in addition to the impossibility of generalizing about input costs and other expenses on a particular operation, determining in which year an orchard might become profitable is not possible to generalize.
The price that a walnut producer receives is dependent upon variety, timing, quality, and other market factors. Specific quality standards vary by geography and purchaser.
Walnut Crop Budget
We highly recommend taking time to understand crop budgets before having a conversation with a citrus to better understand their needs and costs.
- Crop Enterprise Budget Example #1: English Walnuts | Southern San Joaquin Valley (Flood Irrigated)
- Crop Enterprise Budget Example #2: English Walnuts | Sacramento Valley (Micro-Sprinkler Irrigated)
- Crop Enterprise Budget Example #3: English Walnuts | San Joaquin Valley North
It is critical to understand that farm economics and budgets vary widely between individual farm operations, as well as by year, as a result of a landscape of factors, from water availability to input costs. Because of these variations in cost of production, it difficult to generalize about the economic status of a given grower or region.
Walnut Costs
Though there are many fairly standard expenses on in an walnut operation, the magnitude of related costs varies widely based on geography, varieties grown, and weather, among others.
- Capital costs may include;
- Land (rent or purchase)
- Property alterations (like laser-leveling prior to grove planting and installation of sub-surface irrigation)
- Irrigation systems (including installation)
- Initial tree plantings
- Production and harvest equipment, facilities, and vehicles (including ATVS, chemical applicators, harvesters, etc.)
- Variable costs may include;
- Water (generally calculated per acre-inch)
- Replacement trees (~1% annually)
- Energy and fuel costs
- Equipment/facilities maintenance and operating costs
- Inputs (including fertilizer, pesticides and other crop protection, etc.)
- Auditing, compliance, and inspections (often charged either per pound or per acre)
- In California, the California Walnut Commission collects mandatory assessment fees of $0.01/pound of dry in-shell walnuts annually.
- Property taxes
- Interest on operating capital
- Insurance
- Labor costs
- Though labor is still a meaningful expense on most walnut orchard balance sheets, the fact that the sector is highly mechanized and efficient means it is not as labor-intensive as many other specialty crops.
- Notably, no single machine completes the full harvest task, and generally there remains work to be done by hand, especially equipment operation and sweeping up nuts missed by the sweeper. It is becoming increasingly common for growers to hire laborers directly to rake additional missed nuts into the windrow. Otherwise, harvest is often carried out by custom harvest crews, which charge the farm by the hour, acre, or yield to complete the harvest. These crews are not employed, and likely not trained, by the grower themselves, but are managed by a crew boss on behalf of a labor contractor.
- Other tasks on the orchard can be more labor intensive than harvesting, especially pruning and planting. Pruning is a task that occupies a relatively short period of time each year, but is critically important to be carried out well. Planting and/or grafting, on the other hand, is only handled a few times a century, and is often outsourced to custom planting businesses who provide labor— rather than growers having to hire workers for this task themselves.
- There are many other labor roles on the orchard, including those who carry out tasks like irrigation, mowing and disking, and pesticide application. Some of this work can also be hired out to custom businesses that will, for example, provide crop protection application services for a fee, providing the machines and workers in the process.
- A walnut farm’s labor force is usually composed of a mix of salaried managers, directly hired full-time, part-time, and possibly some H-2A temporary workers, and indirect laborers who work for a hired labor contractor. Additionally, growers may also hire contractors like pest control or crop protection advisors, accountants, and others.
- In California, minimum wage for agricultural workers is $15.50 an hour, with additional requirements around overtime and days off. Actual labor costs (as predicted by UC Davis in California) are around $26/hour for machine operators and $22/hour for general laborers, including employers’ share of federal and state payroll taxes, workers’ compensation, and other benefits.
- Growers must also cover labor-related costs, like sanitation services. When laborers are in the field, growers are required to supply toilets and wash stations for workers, so portable facilities must be both acquired and maintained while field work is underway.
Key Pressures and Opportunities for Walnut Growers
The availability of water is a top concern for California’s walnut growers. Walnut trees are a water-sensitive crop that need finely-tuned amounts of water to perform productively, both for irrigation and for frost protection. Efficient production, and therefore orchard profitability, often comes down to the benefits and costs related to water.
In recent decades, California has suffered a number of significant droughts, many of which have lasted for multiple years. These have led to limitations on surface water access, even for those with the most senior water rights.
Growers have increasingly turned to ground water pumping, though increasingly, issues with land subsidence (the physical sinking of the land due to absence of sub-surface water) have led to greater scrutiny and regulation on the use of ground water for agriculture in the state.
High levels of irrigation can lead to additional challenges, like the build-up of salts in the soil. This can degrade the quality of soils and, when it becomes extreme, can prove toxic to tree roots, causing yield reductions and endangering orchard health.
Research and technology can help develop water-efficient crop production techniques and strategies to address water scarcity/overabundance challenges while aligning with upcoming regulations on water usage. Additionally, tools should be developed to support crop management strategies that enhance economic sustainability even in regions with limited water resources (generally, but improving water-use efficiency (WUE)). And special attention should be paid to advancing solutions that provide additional benefits (i.e. irrigation strategies that improve nut quality/yield).
Growers increasingly rely on advanced software and hardware tools to precisely manage their irrigation water. Technological emphasis should be placed on developing and implementing irrigation and nutrient automation and precise methods to estimate actual tree evapotranspiration and stress at both individual tree level and scalable plot levels (e.g., 40-acre maps). This will enhance water-use and nutrient efficiency and optimize irrigation and nutrient practices.
Advanced irrigation systems that bring together the advantages of drip irrigation and similar water-saving delivery methods with soil moisture sensors have helped growers reduce their water usage and avoid some the challenges inherent in applying large amounts of irrigation water. Additionally, data from remote sensors (drones, satellites, etc.) have been added to more local data from sensors to create advanced irrigation planning and forecast tools so that growers can determine, often days in advance, exactly how much water a given orchard will need— creating greater opportunity for growers to carefully plan an efficient irrigation schedule.
Technologists aim to further advance irrigation technology with the adoption of control technologies, which allow growers and irrigators to control irrigation system pumps and valves remotely. By doing this (rather than having an employee manually turning valves, checking water pressure, etc.) new possibilities are opened up around how irrigation can occur, especially with respect to frequency and related labor demands.
The farther future of control systems opens the door to autonomous irrigation, where at some point, highly refined sensors will be able to communicate directly with control technologies, so that an orchard, or even an individual tree, can receive water exactly when they need it without direct human intervention.
Increasing the water efficiency of the trees themselves, both through novel breeding and through genetic manipulation, are also potential solutions going forward.
Costs are on the rise for nearly every input to walnut farming, from land costs to labor, fertilizer to equipment. Commodity prices do not necessarily reflect that steadily increasing cost of production that growers face, and so savvy farmers look for ways to reduce the costs of inputs whenever possible.
Labor has become the focus of significant interest in reducing costs, especially as costs (both direct and indirect) related to labor continue to rise and growers see increasingly viable solutions to reducing the number of people employed in the orchard.
Research and technologies focused on labor-saving can aid in mitigating the impact of labor shortages on farm operations. One strategy that walnut growers remain enthusiastic about is mechanical and autonomous tools, especially the potential use of weeding technology for orchards with irrigation systems which could offer innovative solutions for efficient and eco-friendly weed and pest management.
Though there are currently several mechanical tools available in the walnut orchard, there is still labor costs that could be ameliorated through automation and mechanization— including costs related to spraying, pruning, and irrigation are also targets for advancing mechanization and automation, though there already are some autonomous tools available for tasks like chemical application, mowing, and disking (from companies like Monarch Tractor, Blue White Robotics, InsightTRAC, and FieldIn).
Technologists designing for key issues in this field should consider unique features of the industry.
- All automation or mechanization tools will likely require long battery lives, sturdy, rugged construction, and other reliability refinements to deal with dusty field conditions and being used around the clock to travel relatively long distances.
- In most cases, farmers rely on mechanics on-site and do not have access to electronic/robotic engineers.
- Crews who use tools in the field often do not speak English fluently and may not be able to read or write. Crew members may also not be uniformly able to communicate to each other due to language barriers.
- High-speed internet and high-bandwidth cellular services are far from a given in rural areas.
- Orchard factors including row and tree spacing will vary, based on (among other things); variety, orchard architecture, climate, and preferred management practices. The amount of space between rows affects sunlight penetration, canopy management, and equipment access.
- Different varieties, and orchards of different ages, can have variable growth habits, tree vigor, and healthy canopy sizes. This can affect everything from row spacing to harvest practices.
- Equipment and labor access are factors that are commonly considered when determining row spacing during the orchard planning process, however, altering row spacing during the productive life of the orchard is nearly impossible.
- Mechanical harvesters that shake the trunks of walnut trees can be utilized to fell nuts onto the ground where they are then retrieved by a sweeping machine.
- Very little of the harvesting process remains to be mechanized, but both commercially available shakers and ground harvester machines require human operators.
- Pruning and training tasks are often more carefully customized to each particular tree, and generally require a higher degree of expertise to be done at a high level of quality. Therefore these can be particularly difficult tasks to automate.
- Machine vision will likely be a critical component of these types of pruning and training innovations, though these advances are also like to extend into crop protection spraying of weeds and other pests at the in-field level.
- Spraying automation is evolving, with existing sprayer systems able to target tree canopies in young planting or other specific orchard aspects, helping growers reduce spray volume.
- Autonomous sprayer developers, like GUSS Automation, have advanced one of the first autonomous air-blast sprayers. Growers have seen both efficiency gains with these tools and increased precision, tracking and worker safety benefits.
- Aerial drone-based systems are also improving as technologists find ways to improve payload capacity. Companies like Parabug have found success in using aerial drones to do biocontrol applications in nut orchards.
Costs are on the rise for nearly every input to the walnut orchard, from land costs to labor, fertilizer to equipment. Walnut prices do not necessarily reflect that steadily increasing cost of production that growers face, and so savvy farmers look for ways to reduce the costs of inputs whenever possible.
However, some costs are more avoidable than others. For the time being, a few regions in California’s Central Valley are the premier locations for walnut production, and thus reducing land costs by moving an orchard elsewhere is not necessarily feasible. Reducing outlay for fertilizer, crop protection chemistry, water, and equipment is more likely, even though these inputs have volatile pricing due to the global nature of their markets, aren’t easily substitutable, and/or are critical to harvesting a healthy crop, especially giving unique annual conditions.
In addition to direct cost pressures, state and national regulatory conditions, alongside increasing consumer scrutiny, demands that growers continue producing while minimizing their environmental impact, especially through the reduction in use of certain inputs (like pesticides).
Therefore, research and technology should explore cost-effective alternatives especially around nutrient needs (fertilizers) and pest management methods to reduce input use and expenses. In particular, improving nitrogen-use efficiency (NUE) should be a priority.
- Genetic Research for Resilient Rootstocks and Varieties: Expediting the identification and development of rootstocks with reduced input requirements, tolerance to biotic and abiotic diseases, and varieties that combine disease and insect resistance with high productivity and commercial qualities is a top priority for almond growers.
- Precision Yield Prediction: Research efforts should be directed towards precision technology to predict and map expected yields early in the growing season. Accurate yield predictions are crucial for enabling precise management practices and optimizing resource allocation (especially nutrients).
- Management of Soil Pests: Investigation into integrated and effective management approaches for key soil diseases and nematodes can enhance crop health and productivity, especially focusing on biological and cultural pest management for effective control with less pesticide (biopesticides, remote pest monitoring, etc.)
- Overarching needs in pest management include; better ways to manage pests without the use of harsher chemical tools, adaptations of tech to better detect/monitor/treat pest issues, determination of how the use of soil quality/regenerative ag practices affects pests and beneficial insects, genetic resistance to key pests.
- Specific tech needs include; more effective weeders, sniffers/spore counts for early detection, sterile insect and/or pheromone-based mating disruption systems, better monitoring/geospatial monitoring, easier winter sanitation, better understanding of interaction within landscape, post-harvest fumigant alternatives that meet phytosanitary standards, lower risk approaches that work across multiple diseases, resistant rootstocks, better understanding of prevention/early detection, precision management of weeds in middles vs. tree rows, and easier monitoring that accounts for soil variability.
- Smart Sprayers: Development and evaluation of smart sprayers/ new approaches for applying chemistry to trees to reduce drift and improve spray coverage. This will lead to more efficient and targeted pesticide applications, helping to minimize the industry’s environmental impact.
- Transition to Sustainable Pest Management: The pressure to shift from conventional chemistry to sustainable pest management methods in accordance with CA 2025 sustainable pest management roadmap necessitates research into effective alternative pest management approaches – spanning genetics to technology to biologicals to integrated farming systems approaches.
- Finding Alternative Non-Fumigant Control and Genetic Resistance: Research should be dedicated to identifying effective non-fumigant control methods and exploring genetic resistance for key soil diseases and pests in order to reduce reliance on chemical fumigation and enhance crop resilience.
- Adoption of off-ground harvesting equipment to reduce dust, pesticide residue, aflatoxin, and improve overall grower economics.
- Changing Global Competitiveness and Demand: One of the most critical concerns for U.S. walnut growers today is increasing competition from foreign markets and resulting price pressure and reduction in demand. Any technologies that improve U.S. productive competitiveness will provide support for U.S. growers, but special attention should be paid (when innovating for U.S. producers) on tools that optimize for high-value productivity and low cost of production, keeping the competitive advantages of other regions in mind.
- Value Addition from Co-products: Studies can investigate ways to derive more value from co-products such as hull, shells, and woody biomass, potentially opening new revenue streams.
Consideration for Pests and Disease
Walnut production is susceptible to a range of pests and diseases that can impact nut quality and yield, as well as tree health and long term viability of an orchard. When exploring solutions for walnut growers, care should be taken to avoid increasing opportunity for pests and disease to proliferate throughout the orchards (for example, by being transported on equipment). There are several major points during the course of the walnut season when growers need to be particularly vigilante about specific pests, and during which only certain kinds of pest control measures are useful, effective, or allowable. Find more information on recommended Integrated Pest Management (IPM) regimes for walnut orchards here.
Insects
- Navel Orangeworm - a key pest for walnuts in California. It has several agricultural hosts such as pistachios, almonds, and pomegranates as well as nonagricultural hosts in the Californian landscape. Infested nuts are unmarketable because the larvae feed on the nutmeat or kernel, and the damage can also lead to fungal infections such as aflatoxins. Walnuts are most vulnerable during hull split. Key control methods include winter sanitation which is the removal of mummy nuts, population monitoring, mating disruption, choosing resistant varieties, early harvest, as well as biological controls, insecticides, and organic methods are also available. Monitoring for navel orangeworm can include egg traps, pheromone traps, and degree-day calculations. Growers will use one or more of these methods to monitor navel orangeworm populations in their orchards.
- Codling moth - another major pest in California walnuts that tends to lead to reduced quality nuts. Different generations of the moth (up to three can occur within a single season) cause different damage, from causing nutlets to drop from the tree to causing kernel damage that makes the nutmeat unmarketable. Growers will treat codling moth problems with pheromone mating disruption and insecticidal sprays. Monitoring and scouting codling moth populations is critical, especially during and after control actions, to ensure that all the generations have been impacted.
- Walnut husk fly - a problem pest for mature orchards, though susceptibility to damage varies considerably by variety. Husk fly infestations lead to problematic softening and discoloration of the walnut shell, but can also lead to shriveled kernels, mold growth, and lower yields when it occurs early in the season. As much as 30% of the value of walnuts can be lost by early season husk fly damage. This pest is generally treated with pesticide application.
- Walnut scale - this pest can cause damage primarily to the walnut tree itself, rather than predating on the nuts or leaves only. Scales drink liquid from the inner bark of the tree through the twigs and branches, leaving infested trees looking water stressed, and in extreme cases, causing the bark to crack. Scale infestations can also lead to increased Botryosphaeria infection and canker development, further reducing tree health. Biological controls for scale are not reliable, and pesticides are recommended to keep both scale and the diseases they spread at bay. Walnuts are also susceptible to San Jose Scale, Frosted Scale and European Fruit Lecanium, and Italian Pear Scale
- Ants - specifically the Southern Fire Ant and and the pavement ant feed on nuts that are already on the ground. Ants can hollow out nutmeats completely. Prevalence of ants is greater in drip- and sprinkler- irrigated orchards, and in orchards with high instance of weeds or with cover crops. Management is primarily carried out through cultural control relating to keeping the orchard floor clean of both plant material and nuts during harvest. Baits and other control measures are also available.
- Webspinning Spider Mites - there are multiple types of mites that can be found in walnut orchards, all create damage to trees by sucking cell contents from leaves. Leaves then turn yellow and drop off. Severe infestations are visible by the webbing that spider mites create. Yield impacts and tree damage often result the year after the infestation occurs. Spider mites are most commonly a problem in water-stressed areas. Natural predators are important for managing mites, so biological controls are primarily recommended. Cultural controls around reducing dust in the orchard and preventing water stress are also important. Walnuts are also susceptible to Walnut Blister Mites and European Red Mites.
- Other insects of concern include;
Fungus and Diseases
- Botryosphaeria and Phomopsis Cankers - these fungi overwinter on dead branches and shoots, and effect both tree health directly and the quality of nuts, causing branches to turn black and dye and diseased fruit to develop decay lesions. Though cankers can be treated with fungicide applied in the late spring and early summer, good orchard sanitation is the first line of defense against its spread. Pruning diseased limbs, removing and destroying dead/diseased wood, and preventing against the conditions that encourage Walnut scale populations is critical.
- Other cankers include: Deep Bark Canker, Paradox Canker, Thousand Cankers Disease, and Shallow Bark Canker
- Walnut Blight - All green tissue on the walnut tree is susceptible to walnut blight, from leaves to catkins to developing nuts. The bacteria is spread through rain after overwintering on dormant buds. Growers treat walnut blight with the application of protective sprays to buds, flowers, and developing nuts.
- Other walnuts diseases and fungi to consider:
- In walnut orchards, weeds compete with trees for nutrients, water and light, and can contribute to the growth and spread of insect and disease problems. In young walnut orchards in particular, weeds also provide cover and food for gophers, which encourages them to establish habitats in orchards where they may directly predate young trees or damage developing root systems through burrowing.
- Different weeds are of particular concern during different seasons, and growers are encouraged to take regular surveys to stay on top of weed populations and ensure effective control method applications.
- Also, due to the shake-and-collect harvest method, a high volume of weeds on the orchard floor can make harvest more expensive and difficult.
- Weed control plans should be established before the orchard is planted, especially to prevent against perennial weed varieties.
- Weed types vary depending on geography and soil type, but some common varieties include; puncturevine, crabgrass, horseweed, and Panicum spp., and perennial weeds such as johnsongrass, nutsedge, and bermudagrass. Perennial weeds such as curly dock, field bindweed, and dallisgrass are also common.
- Weeds are generally controlled chemically or mechanically, though mulching, subsurface irrigation, and flamers are also used.
- Managing weeds requires care to ensure it doesn’t lead to soil erosion or compaction, which can also have deleterious impacts on nutrients and water penetration. Repeated use of herbicides with the same mode of action can also lead to herbicide resistance.
- Mechanical (tillage) and chemical (herbicide) control methods are most common for weed management in the tree row, though use of mulches, subsurface irrigation, and flamers are not uncommon.
- Vertebrates can be a particular challenge in the walnut orchard, especially during the establishing years for trees.
- In California, vertebrates of concern include ground squirrels, deer, pocket gophers, tree squirrels, and voles.
- Damage can range from direct damage to fruit (i.e. chewing, droppings on fruit), to tree (i.e. eating leaves, damaging roots through burrowing) to damage to grove infrastructure (i.e. damage to irrigation hoses).
- Ground squirrels, gophers, and voles are common problem species in California, which feed on plants and roots and can girdle and kill young trees.
- Additional damage can be done by mice, rats, rabbits, coyote, feral hogs, and starlings. Less common vertebrate damage may be caused by bear or beaver.
Consideration for Climate Change
Climate change and weather are having and will continue to have significant impact son walnut production both domestically and globally, though the exact nature of these impacts in any specific region are difficult to accurately predict. However, given likely changes in precipitation, extreme weather, and seasonal temperatures, all of which can have significant impacts on the quality and quantity of the annual crop, some predict that California may become unsuitable for walnut production.
Overview of California’s Central Valley, showing the distribution of orchards that require winter chill. Source: Climate Change Trends and Impacts on California Agriculture: A Detailed Review.
- Shifting Temperatures and Growing Regions. Walnut trees must be exposed to a certain amount of cold temperatures, or chill hours, during winter months. The Chandler variety is especially sensitive, Chandler trees needs exposure to the right amount of chill hours to properly bloom and fruit. Warmer year round temperatures will likely disrupt chilling patterns, leading to reduced yield and quality, and potentially motivating Northern migration of walnut production in the U.S. Extreme heat during the season can also lead to impacts like reduced fruit size and reduced nut quality. Walnuts are also highly sensitive to late Spring chills, meaning that an increase in late season temperature variability could similarly devastate the crop. Though there will likely be variety advances in the coming years that will make favored varieties more resilient to variations in chill hours and potentially even to killing cold, in the meantime, instability in the annual production might become more likely.
- Precipitation Changes. More than some other nut trees, walnuts are sensitive to both excess wetness and excess dryness. Climate change will likely mean that some regions will experience more frequent and severe droughts or flooding, and more variation on this trend from year to year. Water scarcity and water-logged soils can both impact tree health, particularly if irrigation supplies become limited or the impacts are felt for a long period of time. Further changes in patterns of heat and precipitation will likely to cause shifts in both growing seasons and growing regions, due to changing demand for and access to irrigation water. Experts predict walnut production in California could decline by as much as 15% due to water restrictions alone. As precipitation patterns evolve, growers will need to adjust their management practices, including irrigation schedules and variety selection, in response. Improved water management practices, such as drip irrigation systems and water conservation measures are likely to remain top of mind.
- Extreme Weather. From heatwaves to cold snaps to high winds, increasing instances of extreme weather is likely to have a significant impact on walnut production. Extreme weather effects orchards in many ways, from damaging young trees to disrupting pollination, in general threatening the yield and quality of the crop, and potentially threatening the long-term viability of a given orchard. Though preventing impacts from all extreme weather is impossible, growers will likely be increasingly interested in tools that allow them to mitigate risks related to these events, including through predicting the events and their impacts as early as possible.
- Pest and Disease. Climate change will likely influence the distribution and abundance of pests and diseases that affect walnut trees and nuts, especially Navel Orangeworm. This pest is already capable of impact as much as 30% of the total California harvest, and this is potential is likely to increase over the next 20-50 years. The impacts of these pests will also likely be greater, because higher temperatures and other beneficial conditions allow Navel Orangeworms to move more rapidly through their lifecycle and break dormancy earlier, increasing the timeframe during which they can damage crops. Likely changes in temperature and humidity levels will not only lead to more substantial populations of damaging pests and disease, but may also alter the time of year when they emerge or die-off, which can in turn effect the tools available to growers to control them. Growers will need to adapt their pest management strategies and be vigilant for emerging threats.
Additional Resources
- Walnuts in California (UC Davis Fruit & Nut Research & Information)
- Walnuts (Presented by: FDA and UC Davis Western Institute for Food Safety and Security)
- California Walnuts (Trade/Marketing Association)
- USDA’s National Ag Statistics Service California Field Office Walnut Reports (Acreage, Nursery Sales, Objective Measurement, and Handler Reports)
- Agricultural Marketing Resource Center: Walnuts
- Why it’s a Time of Transition for Walnuts (The Packer)
- Where Do Walnuts Go From Here? (Terrain Ag)
- Global Walnut Market Forecasts (Cardassilaris Family)
- National Nut Grower (Nut Trade Publication)
- Foreign Ag Service (USDA) Global Walnuts Production Data
- Growing Chandler Walnuts in New South Wales: preparing for a changing climate
- Climate Change Trends and Impacts on California Agriculture: A Detailed Review (2018)
- Walnut Orchard Management: Pilot Projects, Field Testing, Adaptive Research and Problem Solving (C.E. Farm Advisors and Specialists, 2020)