How To Grow Winter Squash

Plant Type: Annual
Name: Cucurbita maxima
Light: Full sun to partial shade
Soil Type: Well drained, lots of organic matter
Soil Temperature: 70 -85°
ph Range: 6.0 – 6.5
Watering: Keep moist
Plant (Payson): May 1 – June 10
Planting Method: Seed or transplant
Germination (days): 5 – 12
Transplanting: plant carefully – try not to disturb roots
Maturity (days): 80 – 110
Common Pests: Squash vine borer, squash bugs, cucumber beetle
Common Diseases: Bacterial wilt, downy mildew, powdery mildew, scab, mosaic

Squash plants have both male and female flowers on a single plant. You can tell the difference because the female flowers have a small bulb at the base of the bud that will become the fruit. Male flowers usually appear first. Bees are needed to pollinate the female flowers with male pollen for the fruit to form.

As soon as the soil can be worked in the spring, mix plenty of organic matter into the soil along with well composted manure
to create a loose, nutrient rich medium. Add an organic all-purpose fertilizer at the time of planting.

Winter squash is a frost tender annual that needs warmth and cannot tolerate any frost so plant seeds when soil is warm. You can also start them indoors 4-6 weeks before the last frost, or purchase plants at a nursery center.

Transplanting

Most garden centers will have squash seedlings for sale in early May. Take care to not disturb the roots any more than necessary while transplanting. Put a small amount of organic all purpose fertilizer in the hole and mix with the soil so that the roots don’t touch the fertilizer. Place plants to the basal roots and firm soil around the plant to hold it upright.

Seed

Seeds can be started indoors 4-6 weeks before the expected last frost. Since they grow fast you can also sow the seeds directly into the garden in late May and still have plenty of production. Plant seeds 1 inch deep and lightly firm soil over them. Water thoroughly and keep surface moist until seedlings emerge.

MULCHING

Mulch around the plants once they are well established. Winter squash will be on the vine a long time so it is important to have some sort of ground cover that keeps the fruit off the wet soil.

WATERING

Squash tend to wilt slightly in the hot sun but that doesn’t necessarily mean they need more water. They appreciate a bit of afternoon shade. Placing the plants on the east side of the garden, with taller plants on the west, can do the trick. Keep the soil moist, but don’t over water.

FERTILIZING

Squash are heavy feeders so add plenty of rich compost to the seed bed and feed with side dressings of an organic all-purpose fertilizer throughout the growing season.

Squash plants tend to have large leaves that shade the ground around them, so weeds may not be a problem. A good mulch will also cut down on weed growth.

The most common diseases on squash are bacterial wilt, downy mildew, powdery mildew, scab, and mosaic.

BUGS
Squash vine borer, squash bugs, cucumber beetle, and aphid. Watch for beetles and remove by hand. Check the underside of leaves for eggs. Remove and destroy them. Throughout the growing season, especially toward the latter half of the summer, watch for aphids. They love squash. You can remove them by spraying with water. If that doesn’t keep the aphids away it may be necessary to use an insecticidal soap, but be careful. Squash is very sensitive to soap sprays. Use the mildest solution possible. If squash vine borers are present, slit the stem open with a sharp knife to remove the larva, then place the open stem in wet soil so that it can grow new roots. 

Harvest two weeks before expected first frost. Allow to cure in the sun a couple of hours then place in storage area. Skin of fruit should be hard. You might be able to score the skin lightly, but not break through to the inside.

PRESERVING/STORING

Winter squash is usually baked and can be stuffed with various mixes. Like summer squash, it can be added to soups, stews, and casseroles and can be canned or frozen. If stored at 45° to 60° F. in a well ventilated spot, fruit should last several months.