The three species of squash that we offer represent a wide variety of shapes and colours. Each will cross-pollinate readily within their species. For instance, all C. pepo will cross-pollinate with each other, but not with C. maxima or C. moschata. For people who want to save their seeds, this is a very important consideration. The fruits themselves will not be affected by cross pollination, but the seeds inside will be, so squash need to be grown in isolation from other members of their species if seed saving is the goal. Continue reading below for more information on how to grow squash from seed.
Cucurbita maxima, C. pepo, & C. moschata
Easy, but all squash plants take up space, and some can be huge.
Season & Zone
Season: Warm season
Exposure: Full sun
Direct sow or transplant in late spring once the soil is warm. For transplants, start seeds indoors during the first two weeks of May. Optimal soil temperature: 25-35°C (77-95°F). Seeds should germinate in 7-14 days.
Sow seeds 2cm (1″) deep. Sow 3 seeds in each spot where you want a plant to grow, and thin to the strongest plant. Space summer squash 45-60cm (18-24″) apart in rows 90-120cm (36-48″) apart. Give winter squash and pumpkins even more room with a minimum of 90-120cm (36-48″) apart in rows 120-180cm (48-72″) apart.
Ideal pH: 6.0-6.8. These big plants need lots of food. Use 1 cup of complete organic fertilizer worked into the soil beneath each plant. All squash grow male flowers first, at later female flowers. The female flowers have tiny fruits at the base of their petals and require pollination by bees mostly. Incomplete pollination often happens at the beginning of the season, and results in misshapen fruits that are withered at the blossom end. Just discard these damaged fruits before they begin to rot. Encourage bees to visit the garden by growing Phacelia, sunflowers, or buckwheat for improved pollination.
Summer Squash: Pick when small, if fruit gets big the plant stops producing. Check the plants regularly.
Winter Squash: Fruit is ripe if your thumbnail doesn’t mark the skin and the stem is dry and brown. Cut the stem about 4cm (2″) from the fruit. Squash survive a light frost, but store better if harvested before frost.
Storage: Field-cure for 10 days in the sun, or cure indoors in a warm room for 4 or 5 days. To prevent mould sponge the skins with a solution of 10 parts water to 1 part chlorine bleach. Store at 10-15ºC (50-60ºF) with low humidity with good air circulation. Try on a shelf in the garage.
In optimal conditions at least 80% of seeds will germinate. Usual seed life: 2 years. Per 100′ row: 180 seeds, per acre: 15M seeds.
Diseases & Pests
Bacterial wilt (Erwinia tracheiphila) – Remove an destroy infested plants. If striped or spotted cucumber beetles appear, control as early as possible. Powdery mildew – avoid wetting foliage if possible. Water early in the day so that above ground parts of the plants dry as quickly as possible. Avoid crowding plants and eliminate weeds around plants and garden area to improve air circulation. Viral disease – remove and destroy entire infested plant along with immediately surrounding soil and soil clinging to roots.
Companions: corn, lettuce, melons, peas, and radish. Avoid planting squash near Brassicas or potatoes. Borage is said to improve the growth and flavour of squash. Marigolds and nasturtium repel numerous squash pest insects.