Sweet Corn Production

Sweet corn is a crop that lends itself well to small-scale and part-time farming operations. The initial investment is relatively low, and many field operations, such as land preparation, planting, and harvesting, can be custom hired. Equipment needs on small-acreage farms are not very great, and most equipment can be used for other purposes.

Corn, also known as maize, is native to the Americas and has been cultivated in Central America since 3500 BC. It was an important food of the Incas, Aztecs, and Mayas of Mexico, as well as the cliff dwellers of the southwestern United States. Iroquois, Haudenosaunee (ho-dee-no-SHOW-nee), or Ongwen’onweh (ongk-way-HON-way) in Pennsylvania and New York grew a variety of sweet corn that turned blue as it matured. In the 1500s corn was taken to Spain, and from there it was quickly introduced into France and Italy. Corn ranks first in world grain production, followed by wheat and rice.

About 60,000,000 cwt of sweet corn is grown annually (NASS, 2022) on about 500,000 farms across the United States (2017 Census of Agriculture), and has a value of about $775 million (NASS, 2022). Based on the value of production, the top five sweet corn states are Florida, California, Georgia, Washington, and Minnesota. Nationwide, sweet corn production has declined by almost one quarter in the past five years. In Pennsylvania, sweet corn is grown on about 11,500 acres by 1,600 farms (2017 Census of Agriculture).  

Marketing

Sweet corn grown in Pennsylvania is usually available from early July to the end of September. When planning production, first consider your ability to market. Several marketing alternatives are available to the sweet corn grower: local retailers, roadside stands, pick-your-own operations, wholesale marketing, produce auctions, and cooperatives. Most Pennsylvania-grown sweet corn is destined for fresh markets and is commonly sold from open bulk containers or by the dozen in plastic bags. The processing market is only suitable for large, highly mechanized growers. Production of less than one acre of many vegetable crops is typical for most Pennsylvania growers. You should conduct some market research before planting sweet corn since many growers overestimate their ability to sell in a given market.

Retail marketing options, including roadside stands (either your own or another grower’s) and pick-your-own operations, provide opportunities for you to receive higher-than-wholesale prices for your sweet corn. You will have 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 have customers on your farm and accept some waste. Farmer’s 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 Agricultural Alternatives: Developing a Roadside Farm Market.

In wholesale marketing, growers often contract with shippers to market and ship sweet corn for a predetermined price. If you do not use a contractor and choose to ship your corn to a wholesale market yourself, your product will be subject to the greatest price fluctuations. Another wholesale marketing option is produce auctions. These operate weekly; however, you must deliver your sweet corn to the auction. Marketing cooperatives generally use a daily pooled cost and price, which spreads price fluctuations over all participating growers. Local retailers are another possible market, but you must take the time to contact produce managers and provide high-quality sweet corn when stores require it.  For more information on marketing, consult Fruit and Vegetable Marketing for Small-Scale and Part-Time Growers.

Site Selection

Sweet corn grows best on well-drained soils that have good water-holding characteristics. If you grow sweet corn on sandy soil, irrigation is critical for optimum pollination and kernel development; however, having the ability to irrigate is important, regardless of soil type. Soil should have a pH between 5.8 and 6.6. When growing early sweet corn, use soils that warm quickly and locations with a southern exposure to ensure early growth and harvest.

Sweet Corn Types

Corn is classified as sweet, pop, flour, silage, or feed corn, depending on the type of carbohydrate stored in the ear. Sweet corn gets its name because certain genes prevent or slow the normal conversion of sugar to starch during kernel development. In addition to the various sugar types, sweet corn cultivars differ in kernel color (yellow, white, and bicolor) and maturation times—early (less than seventy days), midseason (seventy–eighty-four days), and late (more than eighty-four days). Certain sweet corn types should be planted at least 500 feet from others or have a difference in silking date of at least 12 days because pollination by other corn types will produce starchy kernels (Table 1).  

Sweet corn genotypes and sugar content for commercially-available cultivars

1. su = normal sugar types; se = sugar-enhanced cultivars; sh2 = shrunken-2 cultivars. 
2. To avoid starchy kernels, isolate by at least 500 feet or at least 12 days in silking. All sweet corn must be isolated from field corn and popcorn.

Recommended sweet corn cultivars for Pennsylvania

Note: All cultivars within a color grouping are listed in order of maturation (early to late).

Planting and Fertilization

Sweet corn seed is generally planted when soil temperatures reach at least 55 degrees Fahrenheit and the possibility of hard frosts of 24 degrees Fahrenheit or lower has passed in the area. In southern Pennsylvania, try to plant in early to mid-April, and in northern Pennsylvania, in mid- to late May. Depending on cultivar and planting equipment, the optimal plant population is between 14,000 and 24,000 plants per acre. It is recommended that you sow ten pounds of sweet corn seed per acre, eight–twelve inches apart within each row and with rows thirty–forty-four inches apart. Leaving space for a drive row will also assist with pesticide application and harvest. Spacing decisions depend on the row spacing of your equipment and the availability of irrigation.

You can produce early sweet corn (ready by July 4) in Pennsylvania by planting short-season, early-maturing cultivars and using plastic mulch and/or row covers early in the growing season and/or planting transplants. Black plastic mulch can be installed in the early spring. Then, plant sweet corn through the plastic with a special planter. Clear plastic or row cover can be placed over the planted rows. Another method is to plant the sweet corn in double rows approximately eighteen inches apart in furrows, with clear plastic or row cover placed over the two rows of planted sweet corn. You should put soil along the edges of the double rows to increase the distance between the bottom of the seed furrow and the top of the clear plastic or row cover (ideally six to eight inches). Remove the clear plastic or row cover from the sweet corn rows when air temperature under the cover exceeds 90 degrees Fahrenheit for three consecutive days. Sweet corn transplants can also be used to get an early crop, but they are generally not practical on a large scale (more than an acre). If sweet corn transplants are ready for planting, but field conditions are not favorable, the sweet corn grows too fast and cannot easily be transplanted and established after they are about twelve to eighteen days old.

Fertilizer rates should be based on soil test results and the type of sweet corn planted. Banding the fertilizer is recommended rather than broadcast fertilizer applications. Some of the nitrogen should be sidedressed during cultivation if not using plasticulture production methods. The plants should be twenty-four inches tall when sidedressed.

No-Till Sweet Corn

For mid- or late-season sweet corn production, using a no-till planting system can be a benefit in relation to time, equipment, and labor. Sweet corn can be planted with a no-till planter in a bed prepared with only minimal secondary tillage (such as an S-tine cultivator) or in a previously tilled field without any additional tillage, saving both time and labor. Because sweet corn seed germinates and develops optimally when soil temperatures are at least 55 degrees Fahrenheit, early sweet corn production in no-till planting systems is difficult because of colder soil temperatures. However, by mid-June, soil temperatures in most Pennsylvania areas are warm enough for rapid sweet corn seed germination and growth. In addition, no-till planting systems reduce soil-moisture loss early in the season so more water is available for sweet corn growth later in the growing season. If you’re thinking about using no-till for planting sweet corn, the following factors must be considered to be successful: cultivar, planting date, soil-fertility practices, insect pressure and management, planting equipment, cover crop type and stand, and weed species and population in the field. 

Pest Management

Weed management can be achieved with a combination of cultivation, a good crop-rotation plan, and herbicides. Sweet corn competes well with weeds, but the field should be kept weed-free until plants are at least twenty-four inches tall. If weed infestation levels are low, cultivation alone may be sufficient to manage weeds. Many preemergence and postemergence herbicides are available for sweet corn, depending on the specific weed problem and the corn growth stage.

Insects can be a major problem in sweet corn production. The corn earworm, corn borer, armyworm, flea beetle, Japanese beetle, and corn rootworm have the potential to cause crop losses. Monitoring insect populations with traps or by scouting will help you determine if and when pesticides are needed.

Only a few leaf diseases reduce sweet corn yields. Stewart’s wilt, a bacterial disease, is transmitted by flea beetles feeding on young plants within seven to ten days of plant emergence.

Several animals prefer fresh sweet corn to other plants and will eat the young seedlings or wait until the young ear of corn is ready to harvest and then help themselves to a meal of sweet corn in the field. Deer, groundhogs, raccoons, and red-winged blackbirds can cause serious losses if not controlled. Avoid planting sweet corn in fields surrounded by woods or heavily vegetated hedgerows to reduce losses caused by these animals. The potential for such losses should be accounted for when you develop your production and marketing plan.

Many of the pesticides required for sweet corn production are restricted-use pesticides and require a pesticide license to purchase and use. Pesticide applicator tests are usually administered at county extension offices, so you should contact your local office for dates and times of these examinations. When using any pesticides on your operation, remember to follow all label recommendations regarding application rates and personal protection equipment (PPE) requirements. Also remember that any Worker Protection Standards (WPS) apply to the owner as well as to employees. 

Harvest and Storage

Harvesting small acreages of sweet corn is usually done by hand. New mechanical harvesters can cost over $60,000, so these only make sense if you are growing sweet corn on a large scale. Regardless of the harvesting method, check ears for worms, insects, and bird damage to ensure you are marketing a high-quality product.

Immediately after harvest, refrigerate and store sweet corn in plastic bags, preferably in the husk, to maintain quality. Sweet corn will retain fairly good ear quality for two to three days if stored at 90 percent humidity and 32 degrees Fahrenheit.

Environmental Regulations

All agricultural operations in Pennsylvania, including small-scale and part-time farming enterprises, operate under the Pennsylvania Clean Streams Law. A specific part of this law is the Nutrient Management Act. Portions of the act may or may not pertain to your operation, depending on whether you have livestock on your farm. However, all operations may be a source of surface or groundwater pollution. Because of this possibility, you should contact your County Soil and Water Conservation District to determine what regulations may pertain to your operation. 

Risk Management

You may wish to consider several risk-management strategies for your operation. First, you should insure your facilities and equipment. This may be accomplished by consulting your insurance agent or broker. Second, you may wish to insure your sweet corn crop with crop insurance. Third, you may wish to insure the income of your entire farm through a crop insurance program called Whole-Farm Revenue Protection (WFRP).

Crop insurance is a federally subsidized program that is available from private crop insurance agents. There are two types of sweet corn policies available: one based on your actual production history (available in twelve Pennsylvania counties for processing growers) and one that provides protection against declining income due to damage that causes a yield shortfall (available for fresh-market growers throughout the Commonwealth). The amount of insurance for the fresh-market policy is based on the cost of growing sweet corn in a specific area and pays when the annual value of the crop is less than the dollar amount of coverage.

WFRP insures the revenue of your entire farm (including any livestock) by guaranteeing a percentage of your approved farm revenue. WFRP uses information from the past five consecutive years of your Schedule F tax records to calculate the policy’s approved revenue guarantee. The sign-up deadline for WFRP is March 15 for calendar year and early fiscal year tax filers and November 20 for late fiscal year tax filers.

For more on agricultural business insurance, see Agricultural Alternatives: Agricultural Business Insurance. For more information concerning crop insurance, contact a crop insurance agent and the publication Crop Insurance for Pennsylvania Vegetable Crops.

Sample Budget

Included in this publication are three sweet corn budgets: early season fresh-market sweet corn using plastic mulch, mid- to late-season fresh-market sweet corn (hand-harvested), and mid- to late-season fresh-market sweet corn using Bt
(transgenic or GMO) seed for control of ear worms. These budgets utilize custom hire for most of the field work, which could be more economical for smaller acreages. Farmers who have their own equipment should substitute their costs for the custom hire. The budgets summarize the receipts, costs, and net returns for each production option. The 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. These budgets are developed for one acre; however, your scale of production should be based on market considerations. More information on the use of crop budgets can be found in Agricultural Alternatives: Budgeting for Agricultural Decision Making.

Initial Resource Requirements

• Land: less than ten acres
• Labor
• Operator: seven–twelve hours per acre
• Harvesting and packing: thirty-five–forty hours per acre
• Capital: $400–$600 per year

Sample Budget Worksheets

• Mid-Late Season Sweet Corn Budget-Bt Seed
• Mid-Late Season Sweet Corn Budget
• Plasticulture Sweet Corn Budget

For More Information

American Vegetable Grower. Willoughby, Ohio: Meister Media Worldwide, 2007.

Dunn, J.W., J.W. Berry, L.F. Kime, R.M. Harsh, and J.K. Harper. “Developing a Roadside Farm Market.” Agricultural Alternatives series. University Park, PA: Penn State Extension, March 2006.

Dunn, J.W., J.K. Harper, and L.F. Kime. “Fruit and Vegetable Marketing for Small-scale and Part-time Growers.” Agricultural Alternatives series. Penn State Extension, May 2009.

Harper, J.K., S. Cornelisse, L.F. Kime, and J. Hyde. “Budgeting for Agricultural Decision Making.” Agricultural Alternatives series. EE0092. Penn State Extension, March 2019.

Harper, J.K. and L.F. Kime. “Crop Insurance for Pennsylvania Vegetable Crops.” University Park, PA: Penn State Extension, July 2020.

Kime, L.F., J.A. Adamik, J.K. Harper, and C. Dice. “Agricultural Business Insurance.” Agricultural Alternatives series. UA406. Penn State Extension, May 2019.

MacNab, A. A., A. F. Sherf, and J. K. Springer. Identifying Diseases of Vegetables. University Park: Penn State Extension, 1994.

Mid-Atlantic Commercial Vegetable Production Recommendations. University Park: Penn State Extension, 2022.

Websites

North Carolina State University Extension Vegetables

National Sustainable Agriculture Information Service (ATTRA)

Ohio State University: Sweet Corn Production and Management Focus of Ohio State Extension Program

Risk Management Agency Crop Insurance Policies: Fresh Market Sweet Corn

Pennsylvania Vegetable Growers Association, RR 1, Box 392, Northumberland, PA 17857-9723

This publication was developed by the Small-scale and Part-time Farming Project at Penn State.

Prepared by Elsa Sánchez, professor of horticultural systems management; Lynn F. Kime, senior extension associate in agricultural economics; and Jayson K. Harper, professor of agricultural economics.