Growers looking for a crop to round out their roadside market offerings or sell to commercial buyers should look at summer and winter squash as possible revenue sources.

The Agricultural Marketing Resource Center (AgMRC) reported that in 2013, the United States grew close to 6.3 million cwt of squash for markets around the country. Producers pulled in $237 million.

Many squash farmers shared in this gold mine by being able to price their fresh squash from $1 up to $3 per pound, an incredible 200 percent price dispersion.

Georgia is the nation’s leading squash state, producing about a quarter of the commercially grown squash.

Wherever they are located, farmers grow two main types of squash, summer, and winter, both of which have their own sub-groups. Summer squash can be categorized by three primary variations: zucchini, yellow squash (straight and crookneck), and Hubbard. Some varieties have a bush-type growth instead of the vining habit. These are worth considering in areas where space is at a premium.

Winter squash includes butternut, acorn, and spaghetti squash. The name “winter squash” does not refer to when the producer plants or harvests the squash but rather to the time when the squash is sold.

Winter squash actually require full sunlight and soil that is 70 degrees Fahrenheit to properly mature, according to horticulturalists at Cornell University. The majority of producers cannot find these conditions during the winter, however.

A question that bothers many newcomers to squash production is why producers do not sell the winter squash with the summer squash since both are grown in warm weather. Technically that is possible, but you would not be maximizing the natural characteristics of winter squash.

AgMRC noted that winter squash has a hard outer shell with a thick rind and an orange flesh that is reminiscent of the inside of a jack-o-lantern. Because of these defining characteristics, winter squash can be stored for long periods of time and sold when the season’s summer squash is gone.

Summer squash typically does not store well and are best marketed as they are harvested.

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Planting squash

Squash will grow on various soil types with proper management, University of Georgia Extension Horticulturalist George E. Boyhan said. In all cases, he recommended planting in well-drained soil. “Previous crop history should also be considered when selecting a site,” he said. Avoid land that has been in cucurbits the previous year. Also, check for previous use of long-residual herbicides as well as heavy nematode infestation.

Producers can buy seeds locally or from online stores such as Most outlets sell summer squash, winter squash, and specialty winter squash. In small quantities, the most seed will cost $5 for a pack of 30 seeds. One-pound sacks of squash seed sell for $40 and a 5-pound sack costs about $110.

Plant squash in full sun in 3-foot rows. Plant seeds about one-half inch deep and 4 to 6 inches apart in the row. When plants are in the one to two true-leaf stages, thin them to a 12- to 15-inch spacing, selecting the most vigorous seedlings.

Producers in a state with a long summer season can sow seeds directly in hills or rows two weeks after the last frost-free date. Squash will respond well if planted in hills. Rows should be spaced 4 to 6 feet apart, with hills 3 to 4 feet apart within the row. Place two or three seeds in each hill.

Winter squash, particularly vining types, require 80 to 120 days to mature. About 2 pounds of seed are required to produce vining squash types that are planted with 5 to 8 feet between rows and 2.5 to 5 feet within rows.

Producers who live in a state with a short growing season can get a jumpstart by starting seeds in an indoor environment at least three weeks before the last frost is predicted. After passing the frost-free date and the soil starts to get warm, transfer the plants outside.

Field preparation will determine the quality of squash later. The best soil for producing squash should maintain a pH between 6.0 and 7.0. Nitrogen fertilizer is recommended to maximize summer squash yields.

Extension specialists at Clemson University warned against planting this crop until after the last chance of frost has passed and the soil temperature at the 4-inch depth is 60 degrees Fahrenheit.

Fertilizer rates will be determined by a soil test. Provide only missing nutrients. Organic materials such as manures and compost are recommended by the University of California’s Integrated Pest Management team (UCIPM) at Davis.

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Fertilizer can be broadcast prior to planting or banded (apply 2 inches below and 2 inches to the side of seed or transplants) at time of planting. Because nitrogen is readily leached from soil, it is always recommended by Boyhan. On Coastal Plain type soils, nitrogen should be applied at 100 to 120 pounds per acre. On Piedmont, Mountain, and Limestone Valley soils, the rate can be somewhat lower with N applications ranging from 80 to 100 pounds per acre.

Clemson recommends sidedressing before the vines start to develop, using 33-0-0 at 1 pound per 100 feet of row or calcium nitrate at 2 pounds per 100 feet of row. More frequent sidedressing may be required if the soil is sandy or if leaching rains occur. Extension specialists warn against over-fertilizing with nitrogen because this encourages excess vine growth and reduces fruit growth.

Water requirements

It is even more important to pay attention to the amount of water available when prepping the soil and through the season.

Squash is a thirsty crop, requiring adequate moisture to produce high yields of quality fruit. About 1 inch of water is required each week during production. On sandy soils, higher amounts of water may be required and that might mean irrigation is necessary.

According to UCIPM, at planting, the soil will need to be moist but not soaked. This usually means that only the top 1 to 2 inches of soil needs to be cultivated. There rarely is need for deep tillage or soil ripping unless the soil is being amended for other management reasons.

According to Bonieplants, producers should plan to plant squash seeds 3 to 6 feet apart from each other for them to properly grow and mature.

One acre of squash could yield around 10,800-11,000 individual squash. Assuming optimum conditions, a single acre of squash could bring in around $27,000! Now, let’s say that you don’t sell the squash but instead eat one every day. If you did this the squash produced in one acre would last you 30 years. It is not that easy, however. Those numbers do not take into consideration that powdery mildew, insects or diseases might infest the crop, thus reducing yield. It is rare for a farmer not to encounter at least one of these problems during a season…and there are times when all three might plague the crop.

However, disease and insect challenges should not cause too much worry because these problems are readily fixed. There are solutions from agricultural chemicals and for the producer who prefers to keep it natural.

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Mulching squash

Clemson’s horticulture specialists noted that black polyethylene mulch warms the soil faster in the spring and conserves soil moisture, which usually will result in an earlier harvest.

Other advantages of plastic mulch are weed control and reduction of fruit rot. It is best to use drip irrigation in conjunction with black polyethylene mulch. Use this mulch only for the spring crop. If the fall crop is grown on polyethylene mulch, paint the mulch white, they advised.

For early squash, use a row cover either alone or in combination with black plastic mulch. The row cover can be either clear polyethylene sheeting supported by wire hoops or one of the spun bonded polyester materials that need no support above the developing plants. Remove these materials before the temperatures get above 75 degrees Fahrenheit. Otherwise, high temperatures under the row covers may inhibit plant growth.

Keep in mind that many varieties have separate sexes in flowers. This characteristic is referred to as a monoecious flowering habit. Blossom drop of male flowers is, to some extent, normal because only the female flowers produce fruit. Female flowers can be identified by the swollen ovary at the base of the flower.

Poor fruit set could be due to improper pollination, noted University of Minnesota Extension Horticulturist Vincent A. Fritz. Pollination may be hindered by cold rain and cloudy weather. Tasteless fruit could be due to dark, cloudy weather, or disease.

Perhaps the most common pest is powdery mildew. This is exactly what its name sounds like: a white powdery infestation on the leaf that looks like mildew. This is a common disease that many farmers deal with year after year. The best way to avoid powdery mildew is to promote good air movement in the field. According to Bush, chemical treatment is usually not needed. A better solution is to plant mildew-resistant varieties. Using certified seed helps, too.

Do not confuse powdery mildew with downy mildew. Downy mildew appears as yellow or brown spots on the upper leaf surface. A gray fungus is apparent on the lower leaf surface, particularly in wet humid weather.

If mildew does attack, be sure to destroy all infected plant parts and not leave them in the field so as not to recycle the mildew spores.

Another common problem with summer squash is rotting of the blossom end of the fruit, called blossom-end rot. The main symptom is a dark-colored dry rot of the blossom end of the fruit. Blossom-end rot is caused by a lack of calcium in the developing fruit. It may indicate that calcium is lacking in the soil or that the plant does not have the ability to take up adequate amounts of calcium from the soil.

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Insect pests

If you avoid mildew and instead have pests attack the squash, check for common insect problems like spotted cucumber beetles, striped cucumber beetles, pickleworms, squash vine borers, aphids, and squash bugs. Treatment varies by plot size. The solution in smaller patches can be simple.

According to “The Nearly Complete Guide to Growing Squash” by Lynne Jaques, the easiest natural way to prevent an army of pests from attacking squash is to grow radishes around the squash. This works because pests that enjoy snacking on squash will more often than not stay away from the taste and smell of radishes.

If you decide not to plant radishes or the pests still attack your squash, “Planet Natural” suggests using an insecticide on the infected squash. As with other insecticides, the chemicals will kill the insects, saving the crop from damage.

While insecticides and sprays may work and make the pests disappear for a while, they will not completely rid of pest problems. Sprays, unless applied with extreme precision, usually do not reach the parts of the plant where many pests lay their eggs. To kill these eggs, a producer does not have to use chemicals. A good dose of canola oil can be effective. Canola oil will spread across the plant and when confronted with squash bug eggs, the oil will kill the eggs and the pest problem will be solved.

If the pests get through this first barrier of defense, then use the spray to kill them. This will not do the job entirely though because of the eggs still in the plant, so, after spraying squash with insecticide, to prevent the birth of more pests, canola oil can be spread on the plants to kill the eggs. After planting acres of squash, getting the nutrients in the soil and fighting off pests and mildew, it’s time to harvest the squash. Summer squash can become large but it’s recommended that you pick them small.

Squash vine borer trouble

The squash vine borer is an annual pest of squash. It hits pumpkins, too. This insect is often not recognized as a potential pest, but can be economically important in some years. Winter squash is highly susceptible to attack, according to University of Wisconsin specialists.

The first symptom of squash vine borer feeding damage is when plants wilt midday. This wilting is caused by larvae as they tunnel through vines and destroy the tissue that transports water. Wilt symptoms may be confused with those caused by bacterial wilt or Fusarium wilt. To distinguish between squash vine borer injury and these diseases, look for entrance holes near the base of wilting vines.

Several pesticides are available to treat vine borer. Two to three insecticide treatments, five to seven days apart during the three-week egg-laying period, will control most of the larval borers before they burrow into vines and become protected by vine tissue. Treating plants with runners that are less than 2 feet long is particularly important. Mature plants can grow out of the damage.

Squash vine borers can cause total collapse of the plant. Plant early because squash vine borers and pickleworms are problems later in the season.

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Aphids are a major problem because they can transmit viruses to the plants. Aphids can be washed from plants with a strong stream of water. While there are insecticides labeled for use against aphids, Washington State University Yakima County Extension Specialist Michael R. Bush advises against using a broad-spectrum material that will kill beneficial predators like lady beetles, lacewings and predatory mites.

Harvest time

The perfect time to harvest winter squash is towards the latter end of the season. This will ensure that the squash is fully mature and ready to be stored throughout the winter season. Winter squash will require at least two harvests, perhaps more.

Summer squash, such as the patty pan variety (also known as scallop), is ready to be picked when it is 6 inches long or wide. This assures that the squash’s flavor will be at its prime. In most cases – and especially for fresh market or roadside sales – it is more important to produce a product with good flavor than to aim for tonnage.

Be prepared with sufficient labor and equipment to harvest summer squash at least three times a week. At the peak of production, picking daily or every other day is mandatory.

Pick winter squash with the stems attached. Winter squashes will store for three to five months.

Clemson recommends harvesting zucchini when the fruit is 7 to 8 inches long and scallop types when they are 3 to 4 inches in diameter. Do not leave large fruit of summer squash on the plant because this will inhibit the development of additional fruit.

Winter squash should be stored in a cool but not cold place. The ideal storage site will have a temperature of around 55 degrees Fahrenheit, with good air movement. Relative humidity between 50 percent and 75 percent is best.

University of Minnesota specialists recommends that squash in storage be checked frequently. Remove any that are soft or show signs of spoilage. Remember to treat them gently to maintain marketability and quality.

Curt Harler, who has a B.S. in agriculture from Penn State University and an M.S. in ag from Ohio State University, is a full-time freelance writer specializing in green topics.

Nate Roach is a freelance writer who lives in Steamboat Springs, Colorado. He specializes in green, sports and business writing.