How to Grow Guide: Squash

Squash are a great addition to any garden! They are easy to grow, great climbers to save space (they’re big!), and the harvest stores well for those hearty winter meals. Plus there are so many different varieties!

If you are a new gardener, squash is a great first veggie to grow!

Difficulty: Easy, but all squash plants take up space, and some can be huge so ensure you have a good spot for them. Most climb well so you can utilize vertical gardening techniques.

Season and Zone

Season: Warm season

Exposure: Full sun

Zone: Not winter hardy. Compare the days to maturity to the length of a typical summer in your area. Days to maturity are from transplant date.

When to Plant

Direct sow or transplant in late May or early June once the soil is warm.

For transplants, start seeds indoors during the first two weeks of May.

Make sure plants are in the ground no later than June 15th. Optimal soil temperature: 25-35°C (77-95°F). Seeds should germinate in 7-14 days.

Planting

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″)(1.5ft to 2ft) apart in rows 90-120cm (36-48″)(3-4ft) apart.

Give winter squash and pumpkins even more room with a minimum of 90-120cm (36-48″)(3-4ft) apart in rows 120-180cm (48-72″)(4-6ft) apart.

Growing

Ideal pH: 6.0-6.8.

Squash plants are quite big (and bountiful!) and need a lot of food. As you plant them, add a cup of organic fertilizer or compost into the soil under each plant.

Each squash plant produces both male and female flowers. The male flowers are produced first, and the female flowers are produced later, at the base of the fruit.

The female flowers require pollination by bees. Incomplete pollination results in misshapen fruits and withered flowers at the end.

This occurs in early summer so watch for it. Simply remove any damaged fruits before they begin to rot.

You can increase the likelihood of pollination by utilizing companion planting. Phacelia or Buckwheat will encourage the bees when planted near your squash plants.

Harvest

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 Thieves cleaner.

Store at 10-15ºC (50-60ºF) with low humidity with good air circulation. Try on a shelf in the garage.

Seed Info

In perfect conditions at least 80% of seeds will germinate. Usual seed life: 2 years. Per 100′ row: 180 seeds

Diseases and 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 the leaves, if possible. Water early in the day and on the soil, 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.

Companion Planting

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.