By early August, we’ve picked plenty of summer squash–from the dark green and striped zucchinis to straight yellow, crookneck and patty pan squash. While most of the harvest ends up on our kitchen counter for use in soups, stews, casseroles and in breads, there’s always plenty left over for family and friends. All varieties of summer squash are tasty, but I like zucchini for its versatility–it can be stir-fried, baked, steamed, braised, grated or sautéed. We often eat it fresh off the vine, sliced thin for a salad, or cut into cubes for an appetizer with a creamy dill dip. Two healthy plants can provide as many as 40 or more fruits.

Growing Conditions

Summer squash will grow in ordinary garden soil, but it does best in full sun in a spot that’s rich in humus–the organic component of soil made up of decomposed leaves and other plant materials. We begin sowing seeds directly in the garden in late spring after the last frost date, which is typically May 15 in the Chicago area. Squash seeds rot in cool, wet soil in spring so we wait until the soil temperature is at least 62 degrees F. (You can check your zone at the U.S. Department of Agriculture’s web site.)

I plant a succession of seeds every two weeks or so through early summer until about mid-August. That will give me just enough time to harvest a few more squash before we get a fall frost. Bush-type squash plants need about nine square feet of room while vining types will need a bit more than that.

Although squash plants can withstand a little drought, they perform better and produce more fruits with moderate and consistent watering, especially when rain is scarce. And, drought-stressed plants are more susceptible to insects and disease, so we give all of our vegetables a good watering at least once a week in dry, hot weather.

Blossoms

Squash produce both male and female flowers. Male flowers have thin long stems and typically appear before the female flowers open. The female flowers have thick short stems and a slight swelling at the base where the fruit develops after pollination. A lack of squash could be due to improper pollination. Rain deters bees from moving from male to female flowers. When that happens, you can use a small paintbrush and touch the pollen in the male flower and brush it on the inside of the female flower. If this sounds like a lot of work, have a squash pollinating party!

Pests

Cucumber beetles, squash bugs and vine borers can quickly ruin a squash harvest. To keep the insects out, we place lightweight floating row covers over young plants. The covers let in sunlight and water, but are a great barrier. Once the plants start to flower, we remove the covers.

Squash bug (aka squash vine borer) is a clear-winged moth that flies during the day. You may see it feeding on squash flowers. They lay eggs in groups on the undersides of the leaves. The larva burrows into a stem, often at the base of the plant. This disrupts the flow of water and nutrients and the squash vine stem can wilt overnight. Flip the leaves over and squash the eggs by hand when you see them.

Spotted and striped cucumber beetles also attack squash plants. The adults feed on leaves, flowers and fruit. I carry a pail with an inch or two of soapy water (a few drops of dishwashing liquid will do) into the garden when I’m harvesting. Holding the squash leaf over the pail, I can knock the squash bugs hiding on the underside into the soapy water. It takes a few minutes but it’s an inexpensive way to get rid of the pests, which can also spread disease to the plants.

Squash (as well as pumpkin and cucumber plants) can develop powdery mildew–white powdery growth on the upper surfaces of leaves. It’s spread by fungi in both humid and dry weather and can spread rapidly among closely spaced plants. Plants that have powdery mildew should be thrown away, not placed in the compost where the fungi can remain until the next growing season. One way to avoid this is to grow plants further apart to allow for better air circulation.

Harvest

Summer squash quickly reaches picking size in about six or seven weeks from the time the seeds are sown. To avoid damaging the plant stems, use scissors or a sharp knife to harvest the fruits when they’re small before the seeds begin to form. I like to harvest summer squash when it’s just about four inches long and super tender. Handle carefully so you don’t bruise the skin or flesh. Yum!

Recipe:

Sautéed Summer Squash Noodles (about 10 small servings)

Here’s a simple way to use up your summer squash. I like to cook these veggies just a bit so they’re slightly firm–not mushy.

1 lb. yellow squash (cut into long very thin strips)

Salt, as desired

1 lb. zucchini (cut into thin rounds)

1 leek (about 4 inches of the white part, sliced in thin rounds)

1.5 oz butter

3/4 oz minced fresh herbs, such as tarragon, basil and cilantro

Toss the squash, zucchini, and leeks together in a large bowl.

Heat the butter over medium heat. Add the vegetables and sauté them tossing frequently, until they are heated through and tender–about 5 minutes.

Season the vegetables with salt and pepper. Add the chopped herbs and serve immediately.