Asparagus is a perennial crop that lends itself well to small-scale and part-time farming operations. Multiple markets exist for growers with 5 acres or less, and many field operations that require machinery, such as land preparation and planting, can be custom hired.
Asparagus (Asparagus officinalis) is a member of the lily family (Liliaceae) and is one of a few vegetables that are monocots (plants having only one cotyledon, or seed leaf). Both male and female flowers are produced on the older asparagus varieties, but there are very few to no female flowers produced on the newer all-male hybrid varieties.
Generally, spears are harvested when they are 7 or 9 inches in length and green in color. Varieties with purple spears have also been developed by plant breeders. Excluding light when spears are emerging will produce blanched, or white, spears.
Asparagus is believed to be indigenous to parts of Russia, the Mediterranean region, and the British Isles. It was first cultivated by the early Romans, who used the asparagus for food and medicinal purposes. It was cultivated in England over two thousand years ago and brought to America by the early colonists. However, asparagus was not extensively planted by commercial growers until after 1850.
Most of the asparagus harvested in the United States is sold as fresh produce. The United States produces around 25,000-30,000 acres of asparagus with a value of $80-100 million. U.S. acreage is currently only about one-third of what it was 15 years ago due to increased imports from Central and South America.
Locally produced asparagus is available in the northeastern United States from late April through June. It is traditionally sold in pyramid crates packed with 1.5- to 2.5-pound bunches held with a rubber band. Several marketing alternatives are available to the asparagus grower: wholesale marketing, produce auctions, cooperatives, local retailers, roadside stands, and pick-your-own operations. When planning production, first consider your ability to market. You should conduct some market research because often growers overestimate their ability to sell in a given market. Production of less than one acre of many vegetable crops is typical for most growers. Asparagus is an early season crop, which may benefit retail marketers when combined with other crops.
In wholesale marketing, producers often contract with shippers to market and ship the asparagus for a predetermined price. If you do not use a contractor and ship your asparagus to a wholesale market yourself, your product will be subject to the greatest price fluctuations. Produce auctions operate weekly; however, you must deliver the asparagus to the auction. Marketing cooperatives generally use a daily pooled cost and price, which spreads price fluctuations over all participating producers. Local retailers are another possible market, but you must take the time to contact produce managers and provide good-quality asparagus when stores require it. Depending on your location, processors may or may not be a marketing option. Processors are less likely to contract with small-acreage growers (those with fewer than five acres). For more information on marketing, consult Fruit and Vegetable Marketing for Small-scale and Part-time Growers.
Retail marketing options include roadside stands (either your own or another grower's) and pick-your-own operations, which provide opportunities to receive higher-than-wholesale prices for your asparagus, but you may have some additional expenses for advertising, building and maintaining a facility, and providing service to your customers. With pick-your-own operations, you save on harvest costs, but you must be willing to accept some waste. Farmers markets are another retail option, but you should contact the markets well in advance of the marketing season to be sure space is available and to find out what requirements you must follow. For more information about roadside markets, see Developing a Roadside Farm Market.
Asparagus should be grown on well-drained soils that have good water-infiltration rates and good moisture-holding capacity. The soil should not be compacted and the pH should be 6.2 to 7.0. Growers should avoid planting asparagus in fields where it has been grown in previous years. Asparagus is an allelopathic species--it produces and releases toxic chemicals that inhibit and suppress the growth of young asparagus transplants or crowns. In addition, asparagus is extremely susceptible to Fusarium root rot, a soil fungus that will weaken the plant. Fusarium can survive up to seven years in infected soil and soil fumigation is not effective in reducing long-term Fusarium populations in the soil. Asparagus is extremely salt tolerant.
Planting and Fertilization
Commercially, asparagus can be started in the greenhouse 8 to 10 weeks prior to transplanting in the field or planted as one- or two-year-old crowns. Crowns are developed root systems with a fairly defined storage organ and growth buds.
Growers generally plant approximately 12,000 to 14,000 plants per acre in single rows, with 12 inches between plants in the row and 5 to 6 feet between rows. Whether planting crowns or transplants, the asparagus is planted in an 8-inch-deep furrow with a W-shaped configuration at the bottom of the furrow. The crown and transplant are planted in the W-shaped furrow beneath the soil surface, and the furrow is gradually filled with soil during the growing season. Asparagus usually is planted in May so that extensive foliage (fern) develops before winter.
Fertilizer recommendations should be based on annual soil test results. In absence of soil test results, the recommended N-P-K application rates are 50-100-150 pounds per acre broadcast in the spring of every year before spear emergence.
Weed control can be achieved with a good crop rotation system, herbicides, and straw mulch. Several preplant and postemergence herbicides are available for asparagus, depending on the specific weed problem and the time of year. If infestation levels are light, early cultivation (prior to spear emergence) can help reduce weed problems.
Insects can be a major problem in asparagus production. Asparagus beetles, asparagus aphids, cutworms, and Japanese beetles all can cause crop losses. Monitoring insect populations will help you determine when you should use pesticides and how often you should spray.
Several asparagus diseases can reduce crop yields, especially Fusarium root rot and rust. These diseases can be prevented by having a good crop rotation system, planting in soil with good water and air drainage, and using disease-resistant varieties.
Irrigation is highly recommended and will help ensure a more consistent crop from year to year. Trickle irrigation is greatly preferred over overhead irrigation because it adds water directly to the root zone and does not wet the fruit. Also, very little water is lost from evaporation.
More information on irrigation can be found in Irrigation for Fruit and Vegetable Production and Drip Irrigation for Vegetable Production.
Harvest and Storage
The length of time for harvesting asparagus each year increases gradually until the plants reach full maturity (5 years). The first year after planting, asparagus can be harvested for about 7 days; the second-year harvest period lasts for about 14 days; the third-year harvest period is about 3 weeks; the fourth-year harvest period is 30 to 36 days; and by year five (when the plants have reached full maturity) the harvest period is approximately 6 to 7 weeks. Asparagus spears can be cut with an asparagus knife or snapped off near the soil line. Spears are harvested when they reach at least 7 inches in height and have a spear diameter of at least 5_16 inch. When growing under seasonal temperatures, asparagus should be harvested every day since spears can increase in length by as much as 2 inches per day. Harvesting asparagus when it is greater than 12 inches in length (spear diameter becomes thinner) will reduce the total marketable harvest over the life of the planting.
Proper postharvest handling of asparagus is critical to marketing success. You should cool the picked asparagus immediately after harvest to remove field heat and improve shelf life. Refrigeration immediately after harvest will help guarantee high quality. Asparagus that is maintained at 32 to 36°F and 90 to 95 percent relative humidity will retain good quality for approximately 7 to 14 days.
In the normal course of operations, farmers handle pesticides and other chemicals, may have manure to collect and spread, and use equipment to prepare fields and harvest crops. Any of these routine on-farm activities can be a potential source of surface water or groundwater pollution. Because of this possibility, you must understand the regulations to follow concerning the proper handling and application of chemicals and the disposal and transport of waste. Depending on the watershed where your farm is located, there may be additional environmental regulations regarding erosion control, pesticide leaching, and nutrient runoff. Contact your soil and water conservation district, extension office, zoning board, state departments of agriculture and environmental protection, and your local governing authorities to determine what regulations may pertain to your operation.
Good Agricultural Practices and Good Handling Practices
Good Agricultural Practices (GAP) and Good Handling Practices (GHP) are voluntary programs that you may wish to consider for your operation. The idea behind these programs is to ensure a safer food system by reducing the chances for foodborne illnesses resulting from contaminated products reaching consumers. Also, several major food distribution chains are beginning to require GAP- and GHP-certified products from their producers. These programs set standards for worker hygiene, use of manure, and water supply quality.
These practices require an inspection from a designated third party, and there are fees associated with the inspection. Prior to an inspection, you will need to develop and implement a food safety plan and designate someone in your operation to oversee this plan. You will need to have any water supply used by your workers or for crop irrigation and pesticide application checked at least twice each year. A checklist of the questions to be asked during the inspection can be found at the USDA Agricultural Marketing Service website.
For more information about GAP and GHP, contact your local extension office or your state's Department of Agriculture.
You should carefully consider how to manage risk on your farm. First, you should insure your facilities and equipment. This may be accomplished by consulting your insurance agent or broker. It is especially important to have adequate levels of property, vehicle, and liability insurance. You will also need workers compensation insurance if you have any employees. You may also want to consider your needs for life and health insurance and if you need coverage for business interruption or employee dishonesty. For more on agricultural business insurance, see Agricultural Business Insurance.
Second, check to see if there are multi-peril crop insurance programs available for your crop or livestock enterprises. There are crop insurance programs designed to help farmers manage both yield risk and revenue shortfalls. However, individual crop insurance coverage is not available for all crops. If individual coverage is not available for what you grow, you may be able to use the AGR/AGR-Lite program to insure the revenue of your entire farm operation. To use AGR-Lite you must have 5 years of Internal Revenue Service (IRS) Schedule F forms. For more information concerning crop insurance, contact a crop insurance agent or check the Penn State Extension website.
Finally, the USDA Farm Service Agency has a program called the Noninsured Assistance Program (NAP) that is designed to provide a minimal level of yield risk protection for producers of commercial agricultural products that don't have multi-peril crop insurance coverage.
NAP is designed to reduce financial losses when natural disasters cause catastrophic reduction in production. NAP coverage is available through your local USDA Farm Service Agency office. The application fee for this program may be waived for eligible limited-resource farmers.
Included in this publication are sample fresh-market asparagus budgets. All budgets utilize custom hire for most of the field work, which could be more economical for a smaller acreage. Farmers who have their own equipment should substitute their costs for the custom hire. The first budget summarizes the costs of establishing an asparagus enterprise (there is no income during the year of establishment). The other budgets summarize the receipts, costs, and net returns of an asparagus enterprise for the first year after planting, the second year after planting, and a mature crop. These sample budgets should help ensure that all costs and receipts are included in your calculations. Costs and returns are often difficult to estimate in budget preparation because they are numerous and variable. Therefore, you should think of these budgets as approximations and make appropriate adjustments in the "Your Estimate" column to reflect your specific production and resource situation.
More information on the use of crop budgets can be found in Budgeting for Agricultural Decision Making.
You can make changes to the interactive PDF budget files for this publication by inputting your own prices and quantities in the green outlined cells for any item. The cells outlined in red automatically calculate your revised totals based on the changes you made to the cells outlined in green. You will need to click on and add your own estimated price and quantity information to all of the green outlined cells to complete your customized budget.When you are finished, you can print the budget using the green Print Form button at the bottom of the form. You can use the red Clear Form button to clear all the information from your budget when you are finished.
Sample Budget Worksheets
Initial Resource Requirements
- Land: 1 acre
- Labor: 20-30 hours
- Harvest/grading/packaging: 25-300 hours
- Total capital investment: $1,000-$1,500
For More Information
Cantaluppi Jr., C. J., and R. J. Precheur. Asparagus Production, Management, and Marketing. Columbus: The Ohio State University, 1993. Available from estore.osu-extension.org.
Dunn, J., J. Berry, L. Kime, R. M. Harsh, and J. Harper. Developing a Roadside Farm Market. University Park: Penn State Extension, 2006.
Dunn, J., J. Harper, and L. Kime. Fruit and Vegetable Marketing for Small-scale and Part-time Growers. University Park: Penn State Extension, 2009.
Harper, J., S. Cornelisse, L. F. Kime, and J. Hyde. Budgeting for Agricultural Decision Making. University Park: Penn State Extension, 2013.
Kime, L., J. Adamik, E. Gantz, and J. Harper. Agricultural Business Insurance. University Park: Penn State Extension, 2004.
Lamont, W. J., J. K. Harper, A. R. Jarrett, M. D. Orzolek, R. M. Crassweller, K. Demchak, and G. L. Greaser. Irrigation for Fruit and Vegetable Production. University Park: Penn State Extension, 2001.
Lamont, W. J., M. D. Orzolek, J. K. Harper, L. F. Kime, and A. R. Jarrett. Drip Irrigation for Vegetable Production. University Park: Penn State Extension, 2012.
Lorenz, O. A., and D. M. Maynard. Knott's Handbook for Vegetable Growers. 3rd ed. New York: John Wiley and Sons, 2006.
MacNab, A. A., A. E. Sherf, and J. K. Springer. Identifying Diseases of Vegetables. Penn State College of Agricultural Sciences, 1983.
Pennsylvania Commercial Vegetable Production Guide. Penn State College of Agricultural Sciences, 2013.
Prepared by Michael D. Orzolek, professor emeritus of horticulture; Lynn F. Kime, senior extension associate in agricultural economics; and Jayson K. Harper, associate professor of agricultural economics.
This publication was developed by the Small-scale and Part-time Farming Project at Penn State with support from the U.S. Department of Agriculture-Extension Service.