Squash

Squash is an excellent plant for shading the ground and providing food for your family.

Fortuna white pumpkin plant

Summer and winter squash

There are two types of squash: summer squash and winter squash. This has nothing to do with when they are grown. Instead, it is more about when they are eaten. Winter squash, such as pumpkins, butternut squash, and acorn squash, have hard outer shells that make them easy to store. Summer squashes, such as zucchini and yellow crookneck squash, have softer skins and must be eaten (or preserved) sooner.

Summer squashes tend to have bushier growth than winter varieties, but most squash plants can really spread out, so don’t plant more than you have room for in the garden.

​How to grow squash​

You can leave last fall’s pumpkin to go through the natural cycle of withering, collapsing, rotting, resting, and sprouting, or you can start with seeds. ​

October pumpkin

Early spring pumpkin

Squash seeds are large and flat and should be planted 1” deep. Squash plants do not respond well to transplanting, so it is best to start them where you want them.

Since these plants take up some room, they are often grown in ‘hills’. These hills are usually 6-8” high and 12-24” wide and can support two or three plants. Squash seeds planted in rows should be 18 to 30 inches apart, depending on the variety. Squash can also be grown in containers, raised beds, and towers.

Squash plants are rugged and they thrive in hot, dry summers. They are heavy feeders, require frequent watering, and they prefer a soil pH of 5.5 to 7.5. Digging in some aged compost or manure when creating the hills will go a long way to ensuring a good harvest. Once these plants are established, they need nothing from you but water. During the peak of summer, afternoon wilting is normal and not cause for concern. Plants will need to be watered deeply once or twice a week, depending on the weather. Mulching around plants can reduce the need for water and it stabilizes soil temperatures.

How squash plants grow

As they grow, they create both male and female flowers. These flowers are usually yellow or orange, and the male flowers tend to emerge first. These flowers are edible, but eating the flowers means no fruit. Since there will be some female flowers emerging after all the male flowers have disappeared, you can boost your crop by cutting off and bagging the male flower anthers, which hold the pollen, and applying the pollen to later female flowers with a natural hair paint brush. In the same way, if there are not enough pollinators in your area, you can hand pollinate squash flowers. In fact, research has shown that applying pollen to female flowers manually causes larger fruit that is more likely to reach maturity. Also, the seeds within that fruit germinate faster and produce larger seedlings. This is called the xenia effect. As fruit is produced, many growers place a layer of straw underneath to reduce soil contact and the potential for fungal problems.

Cucurbita female flower with squash bee (USDA ARS)

Male squash flower (RoRo)

Female pumpkin flower

Squash pests and diseases

As always, aphids, cutworms, earwigs, leafhoppers, grasshoppers, leafminers, mites, whiteflies, wireworms, and thrips will lust after your squash plants. (It’s really a wonder that anything grows at all, but grow it will!) Squash bugs, squash vine borers, and cucumber beetles cause the most squash problems. Cucumber beetles can also carry wilt disease. Placing row covers over seedlings and dusting plants with diatomaceous earth can reduce pest populations organically. Powdery mildew and downy mildews, anthracnose, verticillium wilt, root rot, curly top, bacterial wilt, scab, and mosaic diseases can be reduced by planting resistant varieties, avoiding overhead watering, keeping the garden clear of any diseased leaves (and not adding them to the compost pile), and using crop rotation.

Harvesting squash

Squashes should be harvested by cutting the vine with a sharp knife about one inch above the fruit. Do not twist or yank at it, as this can damage the plant. Summer squashes are best harvested young and eaten fresh. Of course, if you just can’t take another zucchini stir-fry, or you discover a specimen the size of a horse leg, you can always treat yourself to some chocolate zucchini cake or stuff it with some sausage and bake it. You can also cube, blanch, and freeze summer squash for use in soups and stews, but it tends to disintegrate. Winter squash, on the other hand, can be stored in a cool, dry, shaded area, such as a garage, for several months. I’ve had butternut squash that lasted nearly two years and tasted just as sweet and flavorful as fruit from the same vine that was eaten a year before.

Butternut squash crop from two plants

Healthy squash plants can produce an astounding amount of food. This makes them an excellent Plant It Forward addition to your garden or landscape.​