Squash is a warm-season crop, very susceptible to frost and light freezes. Summer squash can be grown almost anywhere, as the vines develop quickly. Harvest begins in two months.
Sow squash directly outside at least a week after your last frost date, or when the soil temperature has warmed to at least 60 degrees F at a 2-inch depth to ensure your seeds don’t rot before they sprout. You want the air temperatures to be settled to avoid last spring frosts.
- Tip: In non-tropical parts of the country, the soil will be about 60 degrees F when roses are in bud and lilacs are in bloom.
The same goes for transplants: Don’t set them out until the weather has warmed to 70 degrees F. Check with your local extension service for up-to-date information in your neighborhood.
- Tip: If you’re growing your own seedlings indoors, use peat pots with the bottoms removed to make it less likely that you’ll disturb the taproot when transplanting.
Don’t rush! Waiting to plant will avoid problems from pests and diseases that are common earlier in the spring season.
How to Plant
In general, squash plants like lots of room to spread out. For summer squash that is mostly bush varieties, space your rows 4 to 6 feet apart, with plants 15 to 20 inches apart.
Pick a spot with full sun, shelter from wind for good pollination, and well-draining soil. Squash like a slightly acidic soil: between 6.0 to 6.8 pH is best. If your soil is too acidic, add lime according to the instructions on your product.
But don’t worry needlessly. Squash can tolerate a soil pH as low as 5.5, so don’t worry about liming unless your soil is strongly acidic. Always perform a soil test (your county extension service or local nursery can help you with this) before adding anything that will affect your soil’s pH.
Squash are heavy feeders and benefit from soil rich in organic matter. Add seasoned manure or mature compost to your soil. For best results, work in one cup of complete organic fertilizer beneath transplants. If planting from seed, work the fertilizer into the top 2 to 3 inches of soil.
A word about sunlight
Squash plants need full sun to produce. Make sure you’re planting your seeds or starts in an area with at least six hours of sunlight per day. More is better, but if the weather gets too hot for too long, your squash plants may droop with stress. If this happens, it’s a sign your plant is trying to conserve its resources. Most will perk up again when the heat subsides in the evening, but if they don’t, consider adding a shade cloth or other temporary heat protection.
Planting methods for seeds and starters
Plant seeds in the ground about 1-inch deep and drop in two seeds. In cold climates, pop a clear jar or half a plastic bottle over the top for warmth, and leave it until the seedlings are up. Remove the weaker seedling.
Another popular planting method is the “hill” method. This keeps the seeds off the ground and therefore warmer. To prepare, dig 18-inch-deep holes, fill partly with well-rotted manure and/or compost, and complete filling the hole and building your hill with a mixture of soil and compost.
Summer squash hills should be placed 3 feet apart each way; plant six or seven seeds per hill and thin to the three strongest seedlings when the plants are 3 inches high.
- Tip: For planting starters that you’ve grown indoors, don’t set them out until you’ve hardened them off. This involves putting them outside in their pots for a week or two for a short time, increasing the time daily.
Water your starters and seeds thoroughly after planting. Add a layer of mulch around starters to lock in soil moisture.
Do you use the hill method for planting your squash seeds or starters? How well has that worked for you? Please share your tips with us.