Summer squash growing guide - gardenstead Skip to content

Summer squash growing guide

Summer squash are some of the most rewarding crops to plant because they grow fast and have the potential to produce large amounts of fruits, resulting in many summer harvests! The look of your squash can vary depending on the variety, and there are many different and delicious varieties to choose from. Some may be long and narrow, or small and round, while others have scalloped edges. Popular types of summer squash include: Eight Ball, Patty Pan and Zucchini.

Planting Squash

  • If growing from seed, start your squash approximately three weeks before the last frost.
  • They are fast growers and don’t need the same amount of time as slower growing heat lovers like peppers or tomatoes.
  • If direct seeding, plant the seeds after all danger of frost has passed (a good rule of thumb is a week or so after your tomatoes go in). Sow seeds an inch deep and approximately 3 to 4 feet apart from each other (they can get big!).
  • Summer squash grow best in well-draining soil in full sun (although they can handle a couple hours of shade).
  • Squash grow large male and female flowers that require pollination. Consider planting pollinators like zinnias or nasturtiums nearby to encourage friendly pollinators to visit (more on the squash blossoms below).
  • Squash does excellent when planted near lettuce so try companion planting for a boost in your garden.
  • Squash are heavy eaters, work in fertilizer and/or worm casting into your planting hole.

Squash Blossoms/Flowering

Flowering & How to Self-Pollinate

  • Every summer squash plant will have male and female flowers, usually at a ratio of 3:1.
  • You can tell the difference between male and female flowers through the stem. Male flowers will have a thin stem, while female flowers have a thicker stem. The fruit grows off the female flowers.
  • If you are noticing the squash plant is doing well but there are not many squash growing, you can self-pollinate the flowers. Take a q-tip or paintbrush and collect pollen from the inside of the male flower. Transfer the tool to the female flower and lightly rub the pollen from the male around the female blossom. You can also do this by removing the male flower and performing the same action. The short video below is an excellent visual guide in how to self-pollinate your squash. 

Common Disease and Pests

Powdery Mildew

  • Powdery mildew is a common disease that looks like splotches of white or light grey powder on the leaves. It’s caused by airborne fungal spores.
  • PM can sometimes be mistaken for a squash’s natural leaf pattern – watch this video to learn how to identify the difference and if your plant is infected or not.
  • As a preventative measure, it’s best to avoid overhead watering and water your squash plants at the soil level.
  • Be confident that it is ok to cut off some leaves that become heavily infected.
  • Many people find that rubbing milk on the infected leaves can help stop the spread (if you are going to try this, do it in the evening as the sun can scald the milk on the plant resulting in leaf burn).
  • Overall, it is very difficult to get rid of PM and it can quickly spread from plant to plant.
  • As always, the key to a healthy garden is to closely observe and to act quickly if you see anything that looks like a pest or disease.

Squash Vine Borer

  • Squash vine borers are the worst! They are larvae that burrow holes in squash stems (and sometimes even the fruit to feed).
  • If you notice wilting leaves, rotting looking stems, or holes at the bottom of your plant it may be a sign of a squash vine borer infection. Your plant could look happy and healthy one day but completely dead looking the next.
  • To catch them in the very early stages (this method is for the brave as this is a very squeamish task!) take a sharp knife and gently cut lengthwise into the stem, about an inch and a half. If you see white looking fat worms, it’s the larva and you’ll need to remove them (there can be more than one in the stem). Then, like a band-aid over a wound, cover the stem with moist soil where you’ve cut to encourage secondary root growth.
  • Some people try covering the stem with tinfoil or another type of material that the pest won’t be able to penetrate through.
  • As a preventative measure, it is always best to practice crop rotation (don’t plant squash in the same spot as the year before)

Harvesting Squash

  • Mostsquash will be ready to harvest in 50 to 65 days. To harvest, cut the squash at the stem using a clean knife.
  • Gigantic fruits are not as tasty as smaller ones, so keep a close eye on your squash because they grow very quickly, especially in hot temperatures.
  • Harvest squash frequently to encourage more production from the plant. If you wait too long, the squash will become woody and lose its flavour and even reduce its yield.
  • If you are overwhelmed with the amount of squash you are harvesting, give them to your neighbors!
  • If you have many squash blossoms on your plant, you can even harvest and eat them. They are delicious stuffed and fried. Blossoms bloom in the morning, so pick them early in the day or they will close up. 

Our Recommended Varieties

Tromboncino – These are one of our very favorites! They are wild, fun and easy to grow if trellised. We tend to pick them around 2-3 feet long but they can grow up to five feet long! They have a light, nice flavour that you can use in a variety of different ways in the kitchen. A must-try!

Patty Pan – These squash are called “scallopini.” You can grow them in a variety of different colors like green, white and yellow. They’re delicious and very productive all summer long.

Eight Ball – These are busy plants that grow dark green round fruits. They have great flavour and are low-maintenance.

Happy Planting!
yellow petaled flower by elias sorey unsplash

hey there

sign up for
our weekly

We promise to only share good stuff about plants and people who love plants.