Planting and Growing Summer Squash: A Guide to Getting Started

If you’re looking to grow summer squash and zucchini, you’re in for a treat! These vibrant vegetables are some of the most rewarding to grow, offering a bountiful harvest in a short period. Whether you’re interested in zucchini, yellow squash, or pattypan, knowing how to get your plants started is crucial to a successful season. In this post, I’ll take you through the steps for planting, seed starting, and transplanting summer squash, from choosing the right varieties to getting your seedlings off to a strong start.

Having grown summer squash in my California garden for over three decades, I’ve learned the ins and outs of the process—especially the importance of getting the plants established properly. I’ll share my tips and lessons learned, focusing on the best methods to ensure your squash thrives from the moment it hits the soil.

Table of Contents

🌱 Choosing the Right Summer Squash Varieties

Before you start planting, it’s essential to choose the right squash variety for your garden. The two main types are bush and vining varieties, each with distinct characteristics. Bush varieties, such as zucchini and yellow crookneck, are compact and ideal for small spaces or raised beds. Vining varieties, such as Tromboncino or butternut, need more space to sprawl or climb, making them perfect for larger gardens.

Tips from My Garden:
In my garden, I’ve had great success with zucchini, especially the black beauty variety. It’s reliable and prolific. However, I’ve also learned to love growing Tromboncino squash for its rich, nutty flavor and unique shape. For smaller spaces, I always opt for bush varieties, which are easier to manage.

🌞 When to Start Summer Squash Seeds

Summer squash thrives in warm temperatures, so it’s crucial to plant them when the soil has warmed to at least 70°F (21°C). In many regions, the last frost date is a good guide for determining when to start. If you’re in a cooler climate, you may want to start seeds indoors 2-4 weeks before the last frost date, giving them a head start.

Direct Sowing: For many gardeners, directly sowing seeds in the ground after the last frost is the simplest and most effective method. Make sure the soil is warm enough (ideally 65-75°F) to encourage quick germination.

Transplanting: For a head start or if your growing season is short, you can start seeds indoors in pots or seed trays, planting 1-2 seeds per cell. I recommend transplanting seedlings when they are about 4-6 inches tall and have developed at least two sets of leaves.

Tips from My Garden:
I typically start my zucchini seeds indoors in small biodegradable pots around mid-April. Once they’ve grown strong enough, I transplant them into the garden after the danger of frost has passed—usually in early May. Starting seeds indoors allows me to get a jump on the growing season, and it’s always satisfying to see those first seedlings make their way into the garden.

🌿 Preparing the Soil for Summer Squash

Summer squash thrives in fertile, well-draining soil that’s rich in organic matter. Squash plants are heavy feeders, so preparing the soil well is essential for healthy growth. I recommend mixing in compost or well-rotted manure to improve soil fertility. Aim for soil that’s slightly acidic to neutral (pH 6.0 to 7.5), as squash plants prefer these conditions.

If you’re planting in rows, space them 18-24 inches apart for bush varieties and 24-36 inches apart for vining varieties. Raised beds or mounded soil work well, as it helps with drainage and warmth, which squash plants love.

Tips from My Garden:
Before planting, I always work in a generous amount of compost to ensure the soil is rich and holds moisture well, but also drains freely. In my garden, I usually plant squash in small mounds, which warm the soil faster and help with water drainage. I also like to add bone meal to the soil before planting, which supports strong root development, especially for young seedlings.

🌱 Planting Summer Squash Seeds or Seedlings

Now that your soil is ready, it’s time to plant. If you’re sowing seeds directly, plant them about 1-1.5 inches deep into the prepared soil. Vining types need more space, so plant them at least 24 inches apart, while bush varieties can be planted closer together, about 18-24 inches apart.

Transplanting: If you’ve started seeds indoors, dig a hole slightly larger than the root ball of each seedling. Be careful not to disturb the roots too much while transplanting. Gently place the seedling in the hole and cover it with soil, leaving the top of the root ball just at soil level.

Tips from My Garden:
I always create a small mound of soil when transplanting zucchini seedlings. This allows the plant to get established quickly and ensures that the soil drains well around the roots. When transplanting vining varieties like Tromboncino, I give them at least 3-4 feet of space to spread. I also ensure the young plants get some afternoon shade during the hottest parts of the day for the first week or two, helping them settle into their new environment.

🌿 Watering and Caring for Newly Planted Squash

Newly planted squash needs consistent moisture to establish its roots. Water deeply to encourage strong root growth, but avoid overhead watering, which can promote fungal diseases. Squash plants thrive on deep watering, aiming to provide 1-1.5 inches of water per week.

Tips from My Garden:
When I first plant squash seedlings, I make sure to water them regularly for the first two weeks. I use a soaker hose to water the base of the plants and avoid wetting the foliage. I also mulch around the base of each plant with straw or grass clippings—this helps retain moisture and keeps weeds down, which is crucial for new seedlings.

🌸 Pollination and Flowering

Once your squash plants are established, they’ll start flowering. Squash flowers come in two types: male flowers, which appear first, and female flowers, which have tiny fruit at their base. Pollination is essential for fruit production, so encourage bees and other pollinators to visit your garden by planting nectar-rich flowers nearby.

If you’re having trouble getting a good set of fruits, you can hand-pollinate by transferring pollen from male to female flowers using a small paintbrush.

Tips from My Garden:
I always plant borage and marigolds next to my squash to attract pollinators like bees. I’ve found that early morning is the best time for hand-pollinating, as the flowers are freshest and the pollen is most viable.

🌿 Managing Pests and Diseases in the Early Stages

Like all crops, summer squash can face challenges from pests and diseases, especially in their early stages. Common pests like squash bugs and aphids can quickly damage young plants, while diseases like powdery mildew can affect the leaves. Regularly inspect your plants and remove any pests by hand. Using row covers early in the season can also help protect tender seedlings from insects.

Tips from My Garden:
I’m especially vigilant in the early weeks, checking for squash bugs and aphids on the undersides of leaves. A gentle soap and water spray works well to control pests without harming beneficial insects. I’ve also had success using row covers during the first month to protect young seedlings from pests while still allowing sunlight in.

🌿 Final Thoughts on Planting and Getting Summer Squash Started

Starting your summer squash plants off right is the key to a productive and bountiful harvest. By choosing the right varieties, planting at the right time, and caring for your seedlings, you’ll set your squash plants up for success. Don’t forget to keep an eye on watering, pests, and pollination to ensure healthy plants that will thrive throughout the growing season. Happy gardening!

Related posts you might find helpful:

Summer Squash

Winter Squash

Squash Planting and Care