Growing Squash in Containers | How to Plant, Grow, & Harvest Squash

Fall is right around the corner, which means flavorful fall recipes aren’t far behind. For us, nothing is better this time of year than a comforting soup, savory salad or decadent pasta. The thing that unites them all? The humble, magnificent squash. 

Growing squash may seem like an undertaking, especially when working in a small space. We’re here to tell you that not only can you grow fall’s most iconic veggies at in your home garden, but you also grow squash in pots without a huge, in-ground plot. We’ll define the differences between summer and winter squash, break down some of squash’s scariest buzzwords (powdery mildew, yikes!), and let you in on which potting mixes produce the best fruits. 

Squash your fears about growing vegetables, and let’s get growing!

How to Grow Squash in Containers

Growing squash in a container is going to be different than growing it in a garden bed, but it is absolutely possible. We’ll do a quick step-by-step breakdown of the process, then provide additional gardening tips on each step later in the article. 

Step One: Decide on Your Varietal

Types of Squash

Before we get our hands dirty, it’s worth it to go over the different kinds of squash. “Squash” is a blanket term for a wide variety of vegetables that belong to the broader gourd family. Because they contain seeds, they are technically fruit and not vegetables. 

Because squash is such a broad term, there is absolutely a plant for every palette. Here are some of our favorite varietals: 

• Butternut–a fall favorite. Known for taking soup, ravioli and bowls to the next level. 
• Acorn–delightful with some butter and brown sugar.
• Delicata–long with a light green exterior, you can eat it with the skin on.
• Honeynut–Butternut’s richer, sweeter little sister.
• Pumpkin–not just for carving! 
• Pattypan–a cute-as-a-button savory squash.
• Zucchini–heroine of succotash, bread, and stir fry.
• Yellow–the reliable favorite.
• Squash Blossoms–not technically a fruit, but a delicious byproduct of a squash plant.
• Zephyr–a hybrid squash with a sweet, nutty flavor.

Summer Squash vs. Winter Squash

As summer turns to winter, we are in a critical moment for squash growth. Choosing the right plant for the right season will give your garden a better chance to produce fruit. The main difference between summer and winter squash is the time of year in which they thrive. 

Summer Squashes

Summer squashes grow quickly in warm weather (many are ready to harvest 60 days after planting). They are a bit more fragile than their winter counterparts, since they must be harvested before they fully mature. Summer squashes left too long on the vine become tough and watery. However, because they are young, their skin is thinner and softer, meaning that they do not have to be peeled before they can be enjoyed. The tender skin adds a flavorful, textural component. 

Types of summer squashes include zucchini, yellow squash, zephyr, and squash blossoms. 

Winter Squashes

Winter squashes are hearty and thick-skinned and thrive best in cooler weather. Because they are on the vine longer than their summer counterparts (80-110 days), they develop a rich color and flavor and a protective outer shell. Their thick skin allows them to last much longer without spoiling. However, many winter squashes must be peeled before cooking, though there are exceptions (such as delicata and acorn). 

Types of winter squashes include butternut, acorn, delicata, honey nut, and pumpkin. 

Squashes for Container Growing

There are several varieties of both summer and winter squashes that grow well in containers. You’ll typically want to look for a varietal that is smaller, both in the size of the plant and the size of the fruit. 

We recommend bush acorn and bushkin pumpkins for winter and black magic zucchini and bush crookneck (a yellow squash) for summer. 

Step Two: Select Seeds or Transplants

After selecting a varietal, you’ll have to decide whether to work with a grown transplant or start from the beginning with seeds. There are pros and cons to each, but at the end of the day, it comes down to personal preference. 

Seeds

If you decide to go with seeds, you will probably have a better selection of varietals than you would with transplants. You will also avoid shocking the plant and have a better sense of when your plant will produce fruit. An added bonus: you can an average of seven seeds for the same price as a single transplant, a significantly greater bang-for-your-buck. 

The cons? Your growing process will take much longer, as seeds will need to germinate and sprout. Seeds are also much more vulnerable than transplants, both to hungry animals and insects such as beetles and slugs. You will also need to be much more cautious about rot, water moisture and changing temperatures. 

Transplants

Starting with a transplant guarantees a head start in the growing process, a bonus if you are starting later in the season. Additionally, placement is much more precise, a really important consideration when growing in sometimes crowded containers.

The main problem with squash transplants is their dislike of the transplant process. Many of them go into shock, which stifles the growing process and increases the time a plant needs to produce fruit. Choosing the correct container and being careful to not disturb their root systems can help mitigate some of these issues. Additional cons include lack of varietal availabilities in nurseries as well as an increased expense over buying seeds. 

Step Three: Get the Right Container

Ideal Squash Containers

Squash can grow pretty quickly and needs a good amount of space to flourish. They are also susceptible to being overwatered, meaning that any vessel needs to have good drainage. We recommend a large plastic container at least 24 inches in diameter and 12 inches deep, with at least one drainage hole at the bottom or a Grow Bag that is at least 7 gallons. You may also want a container that includes or is close to a trellis, as some varieties of squash like to grow vertically. 

Using the correct varietal is just as important as selecting the right pot, since smaller plants are better suited for container gardening. 

Space Requirements

The amount of space squash need to grow depends on whether or not it is a bush or a vining squash. 

Bush Squash

Compact bush varieties are well-suited for container growing, as they never produce side vines and are therefore more compact. They can produce large amounts of fruit, but, since they produce them all at once, if something goes wrong (such as an infestation), all harvest is affected. 

Bush-type varieties include yellow and acorn squash.  

Vining Squash

Vining squashes are also suitable for container growing, but they may need some additional support. These plants produce lots of leaves and side vines and typically take up much more space than their bush counterparts. To maximize growing space, use a trellis for additional vertical room. 

Zucchini plants tend to have vining squash tendencies and benefit from a trellis or tomato cage. 

Step Four: Consider Your Soil

Ideal Potting Soil

Squash plants like a potting mix that is water-soluble and light. Their root systems need space to grow and do not always like normal garden soil, which can impact easily and suffocate them. 

When making a mulch, the most important consideration is that it is free of insects or other pests. This is specifically true for bush squashes, which produce fewer leaves and are more susceptible to catastrophic infestation. We recommend starting with a clean potting soil, then adding equal parts compost, peat moss, pearlite and sphagnum for a well-draining base that’s packed with nutrients. 

You will want to add organic fertilizer every two weeks during the growing season.

Starting Your Squash

Your first steps will depend on whether you have chosen to grow seeds or start with transplants. 

We recommend planting two or three seeds about one inch deep and several inches apart in the direct center of your growing container. Keep the soil moist but not saturated for about two weeks, then evaluate which germinated sprout is the strongest. Remove the weaker plants, then only water when the first top two inches of soil are dry.

If you are transplanting, be sure that the base of the plant is watered before potting. When ready, plant one seedling per pot in a hole about twice the size of the pot they came in. Bury the root system completely and patting the soil around them until they can stand on their own. You’ll want to water them daily in the first week to help them acclimatize, then reduce watering to one inch per week until ready to harvest. 

Companion Plants

Because squash plants do grow to be fairly large, we recommend letting them have an entire container to themselves. However, if you feel as if there is room to spare, marigolds and nasturtiums are good companions that can help keep pests at bay. 

Step Five: Get Growing

The squash has entered the container–what comes next? 

Stages of Squash Growth

Stage One: Germination

The first stage of growth is germination, when the seed begins to sprout roots. Under the right condition, germination can take as little as three to four days. 

After developing roots, the seed will start to send up a stem and begin to produce leaves. You’ll want to look for true leaves, which are smaller versions of what typical squash leaves would be. 

Stage Two: Vine & Leaf Growth

The squash plant will continue to grow, developing new leaves and stems. It’s important to look out for issues such as powdery mildew, pest infestation, and root rot during this stage. Growth can be quick and explosive.

Stage Three: Flower & Fruit Production

In the final stage before harvest, both male flowers and female flowers will begin to form. With the help of pollinators, squash will grow behind the blossoms. The flowers will eventually dry up and fall away to allow the fruit to grow. If you are using a trellis, it’s important to provide additional support for the growing squash so that they can remain on the vine for as long as possible.

Summer squash plants can begin to produce fruit in as little as several weeks, whereas winter squashes take several months to mature. 

Ideal Growing Environment

Growing Temperature

Squash seeds need to be planted at a soil temperature of at least 70 degrees Fahrenheit. Any cooler can prevent the seed from germinating and thriving. Summer squash shouldn’t be planted until at least two to four weeks after the last frost of the season. 

Even as more mature plants, squash do not like to be cold. Try to avoid leaving your plants in temperatures below 60 degrees Fahrenheit. 

Sun Requirements

The more sun, the better. Squash need at least six hours of direct sunlight per day. Move your container (gently!) throughout the day if you do not have a place that has consistent full sun.

Watering

Squash seeds need a fair amount of watering in the beginning to germinate, but they do not like to be overwatered. Once the plant begins to grow and flourish, watering should be fairly consistent. Try not to let the first two inches of soil become too dry. 

If your plant’s leaves begin to turn brown or yellow, looks wilted but has damp soil, or has grey-ish, slimy roots, you may be overwatering it.

Pest Prevention

The most common squash pest are insects and animals. Keeping the leaves moist with a spray bottle prevents squash bugs from laying eggs on them, while a combination of milk and dish soap sprayed regularly on plants is enough to deter animals. 

Powdery mildew, a kind of fungus, is also a concern. It looks like a thin layer of white dust on the leaves and is caused by high humidity and lack of circulation. Prune the affected leaves to prevent spread, being sure the disinfect shears before using on other plants. A combination of one part milk to two parts water also works especially well in preventing powdery mildew on zucchini plants.  

Step Six: Harvest and Enjoy

When to Harvest

Harvest readiness varies from varietal to varietal. Summer squashes such as zucchini and yellow squash will need to be harvested when they are between five to seven inches in length. They will continue to grow until they are harvested, but the larger they become, the less flavor they will have. Winter squashes are ready to harvest when they are a deep, solid color and have a hard rind. 

Both types of squash should be cut delicately from the plant with around two inches of stem remaining on the end. 

Storing Your Squash

Squash keep best stored in a 50 degree, dark space. We recommend a pantry shelf, root cellar or even a cabinet. If storing for a long period of time, turn them regularly to prevent soft spots and bruising. 

When stored correctly, squash can keep for up to two to four months. 

Cooking With Squash

We love incorporating squash into our diets year-round! Some of our favorite receipts include:

• vegetarian macro bowl
• pumpkin, pepper and fall herb soup
• corn and zucchini salad with feta. 

GrowPro Frequently Asked Questions

Get Growing!

Ready to become a squash maven? We’re here to help! Check out our store for growing kits and be sure to read our blog for the latest vegetable gardening advice and recipes.