What is the difference between summer and winter squash? The skin. Summer squash, Cucurbita pepo, are harvested before fully mature and while their skins are still tender. From patty pan squash to zucchini, summer squash produce 60-90 days after seeds are planted.
Winter squash, Curcubita maxima and Curcubita moschataha, are harvested when fully mature and their outer rinds have hardened. Winter squash should be left on the vine until the plant has died before picking. Most varieties can be stored and enjoyed throughout the winter, hence their name “winter squash.”
The reward for your diligent care of winter squash comes in the fall when they are ready to harvest. When harvesting, leave at least one inch of stem on the squash and do not carry the squash by its stem, which might break off. A broken stem allows mold to grow inside the squash and ruin it. If a stem breaks off, use the squash as soon as possible.
Hubbard, Kabocha, Delicata, Acorn, Turban, Spaghetti and Butternut squash are winter squash that mature in 80 to 120 days after seeds are planted, depending upon the variety.
Plant winter squash in late July so they have time to produce mature fruit by fall. Choose a location that can accommodate their sprawling vines. To plant, form a raised hill of soil 2 feet by 2 feet in size and 6 inches high. Mix a balanced fertilizer into the soil and plant three or four seeds in each hill, burying the seeds about an inch deep. If planting more than one hill, locate hills 6 feet apart to allow room for the vines to spread.
Keep the soil damp as seeds sprout. In about 10 days, seedlings will appear. When the seedlings are several inches tall, thin them to one plant per hill. Winter squash are heavy feeders. Mix fish emulsion or steer manure in a bucket of water and use to fertilize the plants weekly. Misshapen squash are the result of too little water and/or too little fertilizer. When watering, keep the leaves as dry as possible to discourage powdery mildew.
Powdery mildew is a fungal disease that affects all types of squash. Tiny, white spores attach to the leaves and begin feeding. At first, circular, white spots form. As the fungi spreads, it looks like a dusting of flour is covering the leaves. Eventually, the leaves die.
To prevent powdery mildew, plant squash in a sunny location to keep moisture from accumulating on the leaves. Prune away some of the vines to allow better air circulation and to produce larger squash. When watering, keep the vines as dry as possible. Use neem oil on infected plants at first sign of powdery mildew.
Some gardeners mix 1 teaspoon baking soda in 1 quart water and spray on infected plants. Others mix milk and water 50:50 and spray on the leaves. These remedies work at the beginning of powdery mildew but will not control the mildew once it covers a majority of the plant. To stop powdery mildew from spreading to other squash in your garden, either remove infected vines or the entire plant. Powdery mildew spores float with the wind and easily move from one plant to another.
If you find clusters of tiny eggs on the underside of the leaves, scrape them off. These are squash bug eggs that hatch into small bugs that feed on the leaves. These pests inject a toxin into the leaves and then suck out sap. Places on the leaves where squash bugs have fed turn yellow and then brown. The leaves wilt as the flow of nutrients stops; and eventually, the leaves die.
Early detection is the best way to prevent squash bugs from damaging your plants. Check the leaves each morning and remove any eggs you find using a plastic butter knife. Pick and smash any adult bugs. Some gardeners place a board near their squash plants for the bugs to congregate under during the night. In the morning, the board is lifted and the bugs smashed. Neem oil can be sprayed on leaves to discourage these pests, as well.
To attract bees for pollination, plant nasturtiums nearby. Besides attracting pollinators, nasturtiums also repel squash bugs. Do not be worried if your first flowers don’t form fruit, this is normal. Squash have separate male and female flowers. Male flowers appear first and have thin, narrow stems. Female flowers follow and have a rounded immature fruit at the base of each flower that forms a squash.
Take time in late July to plant a few hills of winter squash so you will have squash to enjoy eating during the winter months.