It doesn’t take much room to grow your own food: a patio, porch, sidewalk, or even a sunny windowsill will do the trick. Container gardening, a practice adopted by many urban growers, provides you the pleasure of gardening with a fraction of the space.
Growing a few vegetables that you buy regularly – whether that be lettuce, tomatoes, peas, or even potatoes – may seem insignificant, but can save you money, cut down on single-use plastic, and lower the environmental impact of what’s on your plate.
Before getting started, address a few of the main considerations for container gardening: which type of container you’ll use, where the containers will be placed, whether you’ll grow from seeds or starters, and the type of soil you’ll use.
The optimal size and shape of a container will vary based on what’s growing inside, although the pot’s material is less variable. Terra-cotta pots are more attractive, and while they might be perfect for your houseplants, they don’t retain water as well as plastic planters, which are also much lighter and less expensive. Regardless, make sure whatever container you use has drainage holes in the bottom for excess water.
Before situating one of your potted plants, determine whether the appointed spot gets enough sunlight based on the plant’s specific needs. Check the spot every hour over the course of a day to see how many total hours of sunlight the plant will get.
Many garden supply stores sell starters – small plants that are ready to be transplanted directly into your container – or, you can grow your own from seed, learning the specifications for individual vegetables, including when they should be planted during the spring or fall growing seasons.
Lastly, fight the urge to use normal gardening soil in containers. Potting soil – some of which is designed specifically for container gardening – provides better aeration and prevents the plant’s roots from becoming waterlogged. Potting soil also helps retain moisture; unlike plants in the ground, container-bound vegetables can’t send out roots to find more water and nutrients. Along with watering the plants frequently – about once a day, in most cases – keep the pots well fertilized by adding compost.
While most vegetables can be grown in containers, a few are particularly well-suited for the task.
1. Leafy Greens
Greens thrive when grown in containers, which also prevent rabbits from helping themselves to your crops and common pests like nematodes from intruding.
Lettuce, kale, arugula, spinach, and Swiss chard all grow best in cooler weather. If temperatures will exceed 80ºF, consider using a moveable container so the leaves can be taken out of direct sunlight on hotter days. Remember that potted greens also require more water than those grown in the soil; for a lower-maintenance option that demands fewer resources (such as large pots and frequent watering), consider growing dwarf varieties.
Spinach will reach full harvest potential in only 40-45 days, while hardier leaves like kale will take a bit longer. Lettuce is quick to bolt, so harvest leaves when they are relatively young and new growth will take their place. Cut lettuce about half an inch from the soil to allow for regrowth, and harvest individual kale leaves from the stalk, pulling down to detach it without damaging the rest of the plant.
Greens will start slowing down in late June/early July when temperatures rise, but plant again in late September to harvest throughout the fall months. Kale and spinach – which grow especially well together – will continue producing throughout the winter in milder climates.
2. Peas
Snap peas, shelling peas, snow peas, and almost anything else from the Leguminosae family will grow well in containers. Most peas take somewhat long to mature – between 60 and 70 days – but require very little attention while growing.
Peas come in either bush or climbing varieties; use anything from fallen sticks to leftover PVC piping as a stake, leftover chicken wire, or a trellis (if space allows) for climbing peas to attach their vines to. Learn how tall your variety will grow before deciding on a staking method, although most varieties are climbing plants and will need support.
The roots of pea plants are relatively shallow, so a windowbox or trough will suffice and allow you to grow more plants. For taller and bushier varieties, use pots 8-12 inches in depth; shorter varieties need only 6 inches. Seeds or starters can be planted as close as 3 inches together.
Check for adequate pea development – and widening of the shell on more tubular varieties like snap peas – before harvesting. Snap peas mature faster (you don’t have to wait for the pod to fill), and are a quicker option for impatient growers.
3. Tomatoes
Tomato plants growing in front-yard planters are a common sight; these flowering nightshade plants are a rewarding vegetable to grow in whatever space you have available.
Choose the tomato variety you’d like to plant, and find a spot that will receive at least 6 hours of sunlight. To keep the plants from competing for resources, grow each in a separate 5-gallon container with good drainage holes. Tomatoes do require frequent watering – as often as once or twice a day during the hot summer months when they’re more mature – and will draw on moisture for much of the day if given water in the morning.
Upside-down tomato buckets are another popular growing method for smaller tomato varieties, and can provide some decoration to a patio or back porch. After cutting a two-inch hole in the bottom of a five-gallon bucket and covering with fiberglass (slicing it like a pie above the hole so there are six triangular pieces that keep the plant in place), poke a tomato starter through the hole and fill up the bucket with potting soil. Water will drain through the hole when the bucket is hung, and the plant can be protected from getting waterlogged in the rain by putting the bucket lid on top.
4. Summer Squash
Similarly to peas, summer squashes come in either bush varieties or long vines. Either will grow in containers, but bush varieties remain more compact. Plant zucchini, yellow crookneck squash, or any of your other favorite varieties in individual pots at least 12 inches deep. Each plant can easily fill out a two-foot-wide pot; be sure not to crowd them.
In order to produce squash, the plants do need both male and female flowers, so the more flower-producing plants you can grow, the merrier, and the better your chances of a high squash yield (even several a week during peak growing months).
If you choose a vining squash, provide a stake to support the plant. Make sure the containers get plenty of sunlight (7 hours a day is optimal), and water when the top inch or so of soil is dry.
5. Green Onions
With their very shallow roots, green onions are a prime candidate for container growing. Plant seeds about half an inch deep, or, if using transplants, plant so the soil covers the white bulb of the onion. For greater assurance of a successful harvest, you can also plant onion sets: small onion bulbs for gardening, which become full onions in about three and a half months.
Leave 1-2 inches of space between the plants. Keep the onions well-watered (whenever the top inch of soil is dry), in a sunny location either indoors or outdoors, and harvest within 40 to 50 days.
When placed in a shallow jar of water, the bulbs will even grow back the green tops that have been cut off.
6. Peppers
Both in and out of containers, peppers – such as bell peppers, chili peppers, and jalapeños – are relatively easy to grow. Hailing from warmer climates, peppers all love sun and grow best in the summer months when the temperature is between 70 and 80ºF. Peppers also thrive in moist soil, and require daily watering (twice a day on very hot summer days). To give space for their roots to grow, plant peppers in pots at least 12 inches in diameter. The branches are prone to breakage once they’re heavy with fruit, so use some sort of support to hold the plants upright.
Bell peppers are ready to harvest in 2-3 months; harvest when green, or allow them to ripen further until they’re red, orange, or yellow. Chili peppers take slightly longer, and should be harvested once they reach their mature color. Jalapeños, chili peppers, and other small varieties benefit from pruning when they’re about 6-8 weeks old, which will allow for new growth and result in a bushier plant.
While pepper plants are self-pollinating, pollinators do help the plants set more fruit. If your plant is situated where bees can’t reach – such as a screen porch or high balcony – try self-pollinating your peppers.
7. Eggplant
For this large plant and member of the tomato family, choose a pot of at least 5 gallons and 12-14 inches in diameter. Eggplants prefer sandy loam soil; create your own by mixing two parts potting soil with one part sand. Keep the soil moist (but not soaked) by watering once a day or more, and perhaps topping with some type of mulch to retain the moisture. Since the vegetables are rather large, the plants will require trellising, unless you purchase varieties (either seeds or starters) labeled as “compact” or “for containers.”
Eggplants are very sensitive to cold – more so than tomatoes and peppers – and need temperatures around 68ºF or higher to germinate. Keep the containers in a sunny area and use darker-colored pots in cooler climates to retain heat. If temperatures dip at night, take the pots inside the house or another protected area.
Harvesting differs based on variety; research which type of eggplant works best for your space and preferences. Generally, however, the plant will reach maturity in about 2-3 months and the fruit will become glossy when mature.
8. Cucumbers
Like eggplants, cucumbers require large pots – ideally 5-gallon or more – which will hold more potting soil and thus retain moisture for longer, supporting their extensive root systems. When shopping for seeds or starters, look for compact varieties, or “parthenocarpic” cucumbers if you live in an urban area without many bees, as they will set fruit without pollination.
Cucumbers love to climb and will need trellising – such as tomato cages or a homemade trellis with string, wire, or wood – which also helps maximize your vertical space. They’ll also need 6-8 hours of full sunlight, and consistently moist soil.
Squash bugs and cucumber beetles are common pests on cucumber plants, but can be suppressed with neem oil.
Check the plant frequently for new fruit, which can go from tiny to enormous in a matter of days. Be sure to pick cucumbers before they grow too large and become seedy and bitter. Follow the harvesting instructions for each variety, and learn how large the fruit should get before being picked. Rather than pulling the cucumbers from the vine directly, snip them with scissors or clippers to encourage new growth and avoid damaging the stem.
9. Potatoes
Even when buried in the ground, potatoes are often grown in bags for easier harvesting, making them a great candidate for container gardening.
Some potatoes can take up to 120 days to mature – including many grocery-store favorites – so look for seed potato varieties (small potatoes for growing new plants) that are disease-resistant and mature within three months. Generally, smaller, “new” potatoes will fare better than large russet varieties in containers.
Ideally, choose a 10-15 gallon container that’s 2-3 feet high; any opaque container will do, although some gardeners opt for special potato bags.
Space seed potatoes about one foot apart. Since the new potatoes will grow above the seed potato, plant them about 6 inches down to allow for growth. As the seed potato develops new rhizomes and tubers and the above-ground plant continues to grow, you’ll need to use additional soil to create mounds around the plant, giving it more room to grow underground. Begin this mounding process when the plant is about 6-8 inches high, covering all but the top leaves, then repeating once it’s again reached this height.
The potatoes are ready to harvest when the plant begins to flower (although new potatoes can be ready slightly before this). Dig through the soil for the potatoes, or dump the whole lot onto a tarp and remove them easily.
Linnea graduated from Skidmore College in 2019 with a Bachelor’s degree in English and Environmental Studies, and now lives in Brooklyn, New York. Most recently, Linnea worked at Hunger Free America, and has interned with WHYY in Philadelphia, Saratoga Living Magazine, and the Sierra Club in Washington, DC. Linnea enjoys hiking and spending time outdoors, reading, practicing her German, and volunteering on farms and gardens and for environmental justice efforts in her community. Along with journalism, she is also an essayist and writer of creative nonfiction.
