Summer squash seeds germinate optimally in warm soil temperatures, with the ideal range falling between 70°F (21°C) and 95°F (35°C). However, the optimal temperature for germination is typically around 80°F to 90°F (27°C to 32°C).

Direct sow only if you live in a warm climate.  Otherwise start seeds indoors 3-4 weeks prior to your last frost date.

Summer squash seedlings should be transplanted outdoors after the last expected frost date, typically when the weather has warmed and soil temperatures consistently reach at least 60°F (15°C) or warmer.

Full sunlight: at least 6-8 hours a day.

Space summer squash 24-36″ apart. For vining summer squash, trellis the plants and space them 12-18″ apart. Be sure to check the seed packet for specifics on your variety’s size. 

Summer squash thrive in warm temperatures, with optimal daytime temperatures ranging between 70°F and 95°F (21°C to 35°C). While they can tolerate cooler nighttime temperatures, summer squash perform best when nighttime temperatures remain above 60°F (15°C). Summer squash are not hardy and will be killed by frost.

Keep the soil consistently moist.  Water at the base of the plants to keep the foliage dry and reduce the risk of diseases.

Summer squash generally does not require pruning for healthy growth or fruit production. If your summer squash plants are dense, prune excess foliage to encourage more fruit production and allow airflow to prevent disease.

When summer squash reaches the desired size and maturity, use a sharp knife or garden shears to cut the squash from the plant, leaving a short stem attached. Harvest summer squash regularly, every few days, to encourage continuous production throughout the growing season. Overripe squash can become tough and less flavorful.

Summer squash are typically grown from seeds. If saving seeds from an heirloom variety, be sure to avoid cross-pollination. Different varieties of summer squash will cross-pollinate with each other. Summer squash can also cross-pollinate with other members of their species, cucurbita pepo, such as pumpkins.

Summer squash are monoecious plants, meaning they have separate male and female flowers on the same plant. It’s common for the male flowers to appear before the female flowers. After the male flowers have appeared and begun releasing pollen, the plant starts producing female flowers. Female flowers contain the structures that, when pollinated, develop into fruits, so do not fret if your summer squash aren’t producing any fruit with the appearance of the first flowers.  This is completely normal, and you will have fruit before long.