Squash plants are a rewarding and low-maintenance addition to your vegetable garden. However, they often take up a lot of growing space. Container gardening is a practical solution for growing veggies in small spaces. In this article, you’ll learn all you need to know about how to grow squash in containers on your patio, deck, or even indoors.
In addition to saving space, there are numerous other advantages to growing squash in containers. For example, you’ll have more control over the plants’ soil quality and light exposure. Plus, you can move the pots as needed. This allows you to adapt to the changing conditions as the growing season progresses. Furthermore, the risk of pest and disease problems is significantly lower.
Water, temperature, and sunlight are some of the most important factors when growing squash in containers. Therefore, select a container garden site with full sun and decent wind protection. Container-grown squash plants also benefit from getting extra radiant heat from a nearby wall.
How to Grow Squash in Containers
Did you know that there are more than 100 different varieties of squash? Generally speaking, there are two categories of squash cultivars: summer squash (Cucurbita pepo) and winter squash (Cucurbita maxima or Cucurbita moschata).
Some of the most common summer squash varieties are zucchini, yellow crookneck squash, and pattypan squash. Summer squash plants are incredibly fast-growing. They typically begin producing fruit within about two months of planting seeds. They’ll be ready to pick around four to eight days after the flowers open.
Popular types of winter squash include acorn, butternut, delicata, spaghetti, and butternut. Winter squash plants grow much slower. Depending on the variety, the fruits take between 80 and 120 days to mature. The squash ripens approximately two months after flowering and gets harvested in late summer or early autumn.
In general, compact bush-type squash varieties are best for container gardening. Popular cultivars include Black Magic Zucchini, Bush Acorn Squash, Zephyr Yellow Squash, Bushkin Pumpkin, and Butterbush Winter Squash.
No matter which kinds of squash you plant, finding a suitable container is crucial for success. Squash plants have a relatively shallow root system and don’t need huge containers. Use a pot at least 12 inches deep and 24 inches wide. For compact bush varieties, a five-gallon pot is sufficient for one plant. If you’d like to grow a full-size squash plant, you’ll need a 15 to 20-gallon pot.
Ensure your containers have drainage holes to reduce the risk of root rot and other fungal diseases. Although they’re beautiful, terra cotta pots aren’t ideal for growing vegetables. The porous material absorbs water, which makes the soil dry out much quicker.
Ideal Soil and Fertilizer for Growing Squash in Containers
For the best possible results, use high-quality potting soil for growing squash in a container. Look for a soil mix that contains organic compost or slow-release fertilizer for nutrients, coconut coir or peat moss for moisture retention, and perlite for drainage. Or, try making your own potting soil to customize the mixture for your specific needs.
Use organic material like leaves, grass clippings, or straw as mulch. This helps retain moisture, insulate the plant’s root system, maintain soil quality, and suppress weeds.
Squash plants are heavy feeders and grow best when fertilized throughout the growing season. Additionally, container-grown plants usually require more fertilizer because nutrients leach out of the soil when water drains from the pot. Furthermore, container gardens also tend to dry out faster than large garden beds, so keep the soil consistently moist.
When you transplant squash seedlings into larger containers, mix in one cup of organic, all-purpose fertilizer per five gallons of potting soil to give the plants plenty of nutrients while they become established. Then, once flowering begins, switch to a fertilizer with more phosphorus and potassium than nitrogen.
As your squash plants develop, apply slow-release organic fertilizer every three or four weeks. Alternatively, feed your plants with a liquid fertilizer diluted according to the product’s instructions every other week.
If you prefer a DIY approach, try making homemade plant fertilizer. This easy recipe with natural ingredients provides all the essential nutrients to keep your squash plants thriving all season.
Homemade Squash Fertilizer
- 2 cups cottonseed meal
- 1 cup fish meal
- 1 cup kelp meal
- 1 cup of bone meal
- ½ cup garden lime
Combine the ingredients in a lidded, airtight container. Then, spread two tablespoons around the base of each plant every three to four weeks throughout the growing season. Finally, store any leftover DIY plant fertilizer in a cool, dry location.
Planting Squash in Containers from Seed
In warm climates, plant squash seeds directly in outdoor containers in late spring whenever the weather consistently stays above 60°F. If nighttime temperatures drop below 40°F, bring the pots inside.
If your region has a shorter growing season, start squash seeds indoors three or four weeks before your forecasted last frost date. Fill peat pots, seedling trays, or a cardboard egg carton with a nutrient-rich seed starting potting mix and pre-water the soil.
Plant squash seeds one inch deep, then lightly cover them with a mixture of soil and compost. Cover your seedling tray with a humidity dome or a long sheet of plastic wrap to hold in moisture.
Germination usually takes five to ten days. The optimal soil temperature for germinating squash seeds is 80-90°F. However, the seeds can’t germinate below 60°F. Using a seedling heat mat helps keep the soil temperature consistent.
When your squash seedlings sprout, place them near a sunny windowsill with at least six hours of bright light each day. If you don’t have a sunny spot indoors, use grow lights to keep your squash seedlings from becoming leggy.
How to Grow Squash in Containers Using a Trellis
In general, most winter squash varieties have a vining growth habit, and most types of summer squash are bush varieties. However, there are of course exceptions, so be sure to check the plant label or seed packet for cultivar-specific information.
Vining squash plants have a large, sprawling growth habit. Their vines often reach 12+ feet. Training your squash vines to climb a trellis or tomato cage saves space and keeps the plants healthier. By keeping the vines and fruits off the ground, trellising also reduces the risk of pest and disease problems and improves air circulation.
Use sturdy materials for your squash trellis frame to support the heavy fruits. Loosely tie new growth to the lattice every six inches and encourage the plants’ curly tendrils to wrap around the supports.
When growing larger squash varieties like butternut, pumpkin, or spaghetti squash, it’s helpful to tie lengths of fabric to the trellis frame to support heavy fruits like hammocks. Doing so prevents them from breaking off the vine prematurely. Repurposing stretchy fabric from old T-shirts or pantyhose works well.
Resolving Common Squash Growing Problems
Even though the risk of pest and disease issues is lower when growing squash in containers, it’s essential to check your plants regularly for signs of distress or damage. Healthy plants are significantly more resilient, and providing them with appropriate levels of water, nutrients, and light is their best defense.
Some of the most prevalent squash pests include aphids, squash bugs, and cucumber beetles. At the first sign of a severe pest infestation, spray all sides of your plant with an organic pesticide like insecticidal soap, neem oil, or horticultural oil. As a preventative measure, use a cold frame or frost cover in the springtime to deter insects from laying eggs on seedlings.
Squash plants are prone to fungal diseases like leaf spot, rust, and powdery mildew. These harmful fungi spread rapidly in damp, warm conditions. Spores often spread through water droplets. So, provide adequate air circulation and keep the leaves dry when watering. If you’d like to find out more about common squash problems, this article from the University of Maryland Extension has plenty of valuable information.
If your squash plants flower but don’t produce fruit, the female flowers are probably not getting pollinated. To facilitate pollination and encourage natural pest control, try companion planting squash with aromatic herbs and flowers. You’ll attract beneficial insects, both pollinators and predators. Beans, borage, coreopsis, cosmos, dill, marigolds, parsley, oregano, and radishes make excellent squash companion plants.
You don’t have to be a master gardener to grow squash in containers successfully. As long as you can provide the proper growing conditions, you’ll enjoy a bountiful harvest of fresh, homegrown squash. The most important considerations for growing squash in containers are using a pot that drains well, planting in nutrient-rich garden soil, providing plenty of water and nutrients, and placing the pots in full sun.
Do you have any suggestions or recommendations for growing squash in a pot? Please share them in the comments below! If you found these vegetable gardening tips helpful, feel free to share this post about how to grow squash in containers with your friends and family.