10 Key Tips For Growing Pumpkins And Squash

These frost-tender plants need warm weather, lots of sun, and plenty of room.

August 3, 2016
how to grow pumpkins and squash
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With summer coming to a close and autumn creeping up on us, you're bound to see some winter squashes like pumpkins start sprouting up in fields and farmers' markets—but if you're ready to take on a new challenge, read on to see how you can grow these festive and delicious fruits in your vegetable garden. (Whether you're starting your first garden or switching to organic, Rodale’s Basic Organic Gardening has all the answers and advice you need—get your copy today!)

summer squash
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Summer Squash

Squash come in two main types: summer squash and winter squash. Summer squash produces prolifically from early summer until the first frost. This group includes both green and yellow zucchini, most yellow crookneck and straightneck squash, and scallop squash. Most summer squash are ready to pick 60 to 70 days after planting, but some reach harvestable size in 50 days.

You can use them raw for salads and dips or cook them in a wide variety of ways, including squash "French fries" and classics like zucchini bread and even in smoothies (seriously, here's how to add them to your blends). Summer squash blossoms, picked just before they open, are delicious in soups and stews, or try them sautéed, stuffed, or dipped in batter and fried.

Summer squash keep for only a week or so in the refrigerator, so you'll probably want to freeze most of the crop.

winter squash
Winter Squash

Winter squash is a broad category that includes butternut, acorn, delicious, hubbard, banana, buttercup, and spaghetti squash. Pumpkins are also in this group, but their flesh is often less sweet than other winter squash. Most winter squash take 75 to 120 days to mature. 

Winter squash are even more nutritious than their summer kin, but the sprawling vines, which can grow 10 to 20 feet long, require more space. If you have only a small garden, try one of the bush or semibush cultivars. (Also try making your own squash trellis with these step-by-step instructions.)

Steam the young fruits, or harvest and bake the squash when they're fully mature. Dry and roast the seeds. Check out these 5 quick ways to cook winter squash.

planting squash
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These sun lovers are sensitive to cold, though winter squash tolerate light shade and cooler nighttime temperatures better than summer squash. Both types of squash are heavy feeders and need a light and well-drained but moisture-retentive soil. You can give them exactly what they need by planting them in specially prepared hills. Space the hills three feet apart for summer squash, while vining winter squash need six to eight feet between hills. 

Summer squash can cross-pollinate with various cultivars of both summer and winter squash, as well as with several types of pumpkins. This won't affect the current season's fruit, but if you want to save seed, be careful not to let crops cross-pollinate. Otherwise, the seed won't be true to type and the following season's crop will potentially be strange-looking or strange-tasting hybrids.

Related: How To Pick Perfect Pumpkins And Squash

A week after the last frost date, or when the soil temperature is at least 60 degrees and the weather has settled, sow six seeds ½ inch deep in a circle on the top of each hill. Thin to the two strongest seedlings per hill. If planting in rows instead of hills, space vining cultivars three to four feet apart in rows eight to 12 feet apart; space bush types two to three feet apart in rows four to six feet apart. To conserve space in small gardens, train squash vines on a tripod. You can also grow vining types on fences and well-supported growing nets.

squash seedlings
Sowing Seeds

In areas with short growing seasons, sow the seeds indoors a month before the last frost date. Plant two seeds per three-or four-inch pot, using potting soil enriched with extra nutrients from your compost pile. Clip off the weaker seedling after seedlings emerge. Water well just before transplanting and disturb the roots as little as possible. Full-grown plants can tolerate cold weather but seedlings are very cold sensitive. Use hotcaps or cloches to protect them until the weather turns hot. 

Summer squash will produce more heavily than winter squash. In either case, unless you plan to preserve or store a great deal of your crop, two vines of either summer or winter squash are probably adequate to feed four people. Unused seeds are viable for four to five years as long as you store them properly. To spread out the harvest, start a second crop about six weeks after the first planting and it will begin to produce fruit around the time your first planting has peaked and the plants are declining.

watering can
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Give seedlings lots of water and keep the planting area moist throughout the growing season. To avoid mildew, water the soil—not the foliage—and don't handle plants when they're wet. Dig weeds by hand until the squash vines begin to lengthen, then spread a thin layer of compost and top it with a thick mulch of hay, straw, or chopped leaves.

Related: 7 Chemical-Free Fixes For Common Lawn Problems

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About six weeks after germination, male blossoms will appear, followed by the first of the female flowers. Squash depend on bees and other insects for pollination and female blooms that drop off without producing fruit probably weren't fertilized. You can transfer pollen from the male stamen to the female pistil by hand, using a soft paintbrush. Or simply pluck a male flower, remove the petals, and whirl it around inside a female flower.

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When vines grow to about five feet, pinch off the growing tips to encourage fruit-bearing side shoots. By midsummer, winter squash will have set all the fruit they will have time to mature, so remove all remaining flowers so the plant can put its energy into ripening the crop. To avoid rot, keep maturing fruit off the soil by setting them on a board or flat rock or by spreading a thick mulch. This is particularly important with winter squash, which will take a long time to ripen.

Related: Make It: Squash Trellis Step-By-Step

squash bug
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Well-cultivated squash will be trouble free as long as you protect young plants with a floating row cover to keep out insect pests. Remove the cover when the plants start to flower to allow for pollination. The two pests most likely to attack are squash vine borers and squash bugs.

Squash vine borers, which are most damaging to winter squash, look like one-inch-long white caterpillars. They tunnel into stems and can go undetected until a vine wilts. Keep an eye out for the adult borer, a wasplike orange and black moth which will lay tiny red and orange eggs at the base of the stem. Rub the eggs with your finger to destroy them, and look for entry holes at the base of the plants, surrounded by yellow, sawdustlike droppings. Cut a slit along afflicted stems and remove and destroy the larvae inside, or inject the stems with Btk (Bacillus thuringiensis var. kurstaki). Hill up soil over the stem wounds to encourage the plant to sprout new roots there.

Squash bugs are grayish brown bugs up to ¾ inch long; nymphs are similar, but do not have wings. Feeding by adults and nymphs causes leaves to wilt and blacken. Hand pick them and drop them in a container of soapy water. Also destroy their red-brown egg clusters on the undersides of leaves. To trap adults, lay boards on the soil at night because the squash bugs tend to congregate beneath them and you can destroy the pests the next morning. Planting radishes, nasturtiums, or marigolds among your squash plants may help repel squash bugs. 

Related: 14 Nontoxic Ways To Keep Pests Out

mildew on plant

In most cases, you can avoid squash diseases by choosing resistant cultivars, rotating crops, and choosing planting sites with good air circulation. But there are some diseases to watch out for including:

  • Anthracnose, a soilborne fungus that causes leaves to develop hollow, water-soaked spots that eventually grow large and brown.
  • Bacterial wilt is a disease that causes plants to wilt suddenly, and infected plants usually die quickly.
  • Downy mildew produces yellow-brown spots on leaf surfaces and downy purple spots on the undersides. These spots eventually spread and the leaves die.
  • Mosaic is a viral disease that results in rough, mottled leaves, stunted growth, and whitish fruit and is spread by cucumber beetles and aphids.
  • Powdery mildew causes fuzzy white spots on leaves. Affected leaves are distorted and the plant may appear stunted. 

Reduce the chance of the disease by controlling problem insects. Immediately remove and destroy vines afflicted with any of these diseases, or place them in sealed containers and dispose of them with household trash.

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Pick zucchini and crookneck cultivars at a tender six to eight inches long; round types are best when they're four to eight inches in diameter. Summer squash will continue setting buds until the first frost, but only if you pick the fruit before it matures—if you allow even one fruit to mature, the plant's overall productivity may decline. Enjoy summer squash fresh or preserve them by canning or freezing; they can also be dried, pickled, or turned into relish.

Winter squash will taste bland and watery and won't store well unless you allow them to fully ripen on the vine. Wait until the plants die back and the shells are hard. A light frost can improve the flavor by changing some of their starch to sugar, but it will also shorten their storage life. It's better to pick all ripe fruits before an expected frost and cover any unripe ones with a heavy mulch. You can even carefully gather the vines and fruit close together and protect them with tarps or blankets.

Harvest during dry weather and use a sharp knife or pruners to cut the fruit from the vine, leaving two to three inches of stem on the fruit. Pulling the fruit off may damage the stem and the whole fruit may soon rot from that damaged end. Clean your harvesting knife between cuts to avoid spreading diseases. Handle squash carefully because bruised fruit won't keep. Never wash any winter squash that you intend to store. Dry all types in the sun until the stems shrivel and turn gray—the exception is acorn squash, which doesn't need curing. If placed in a cool, dry area with temperatures of 45 to 50 degrees and with 65 to 70 percent humidity, winter squash will keep for up to five months. Acorn squash needs a slightly cooler and moister storage area.

Related: 5 Genius No-Mess Pumpkin Projects