By Erin Marissa Russell
Sometimes, you’re looking for plants that grow nutritious vegetables but don’t take up a lot of space. Whether you’re looking to fill out a windowsill garden, plant veggies in your window boxes, or simply have a bunch of smaller containers that you want to grow vegetables in, the plants on this list will be perfect to plant in your shallow containers.
Also called “rocket,” this tasty green adds peppery kick to salads, soups, and wraps, or you can use it in sandwiches the way you would lettuce. Arugula even features as a gourmet pizza topping, often used with prosciutto and balsamic vinegar.
This salad green thrives in cool weather, and best of all, you don’t need a lot of room to grow it. It can be planted in the spring as soon as the soil warms up enough for you to work in it, and you can keep sowing arugula every two or three weeks through August for a continuous harvest. Situate your container where you’ll grow arugula in partial shade to keep it cool in the summer and prevent it from bolting due to the heat. Water consistently to keep the soil evenly damp, and in 30 or 40 days the greens will be ready to harvest.
Baby Bok Choy
Baby bok choy is grown from the same seeds and plants as the standard-sized version of this Asian cabbage. You simply harvest baby bok choy a little sooner, around 21 to 24 days instead of 40 to 50.
Bok choy really flourishes when the temperature is in the sixties, though plants can tolerate short periods of weather up to 95 degrees Fahrenheit (35 degrees Celsius) or all the way down to 27 degrees Fahrenheit (-3 degrees Celsius). The temperature range where bok choy can be grown for long periods without ill effects like tipburn and bolting is between 50 and 75 degrees Fahrenheit (10 to 24 degrees Celsius).
A location that offers full sun is best, though you can grow baby bok choy in partial shade as long as plants get at least three to five hours of sunlight each day. Provide rich soil by amending with organic fertilizer or well rotted compost. Bok choy prefers a pH level between 6.5 and 7.0 but will grow in levels from 5.5 to 7.5.
Plant seeds spaced one inch apart and an inch and half deep. Thin them to stand four inches apart when you’re growing baby bok choy once they’re a couple of inches tall. These plants like a lot of water, so keep the ground evenly moist, especially when they’re young; a layer of mulch can help the soil retain moisture and stay cool.
This tasty bitter green, despite its name, is more closely related to mustard greens than it is to broccoli. Broccoli raab is a plant that flourishes in cooler weather and will be ready for harvest in only 45 days.
It’s possible to grow broccoli raab in partial shade, but the plants will do their best in full sun with soil between a pH level of 6.5 and 7.5. Soil should be well draining and amended with plenty of organic material, like well-rotted compost. Be conscious of the weather forecast, as you want plants to mature when the weather is chilly but should avoid frosts, which can kill the plants.
Space your plants to stand 16 inches apart, and water well, especially when the weather is dry. Fertilize them every two or three weeks with a half-strength fish emulsion to give them the boron they need to thrive. To encourage a better harvest, pinch off the first bud each plant produces.
Garlic is a garden standby because it’s so easy to grow and is a common ingredient in recipes, so you know your harvest is bound to get used in the kitchen.
Choose a sunny location for your garlic, and plant it in well-draining soil. You may wish to add a bit of sand to your potting soil blend to encourage better drainage. Shoot for a pH level between 6.0 and 8.0, and consider feeding your garlic plants with a 5-10-10 organic fertilizer. Plant your garlic between the beginning of fall in areas where weather is cooler and the beginning of winter in more temperate regions. Each clove should be planted an inch deep, with plants spaced between four and six inches apart.
Don’t permit the soil to dry out between waterings, though you don’t want to let it remain waterlogged, either. Overly saturated soil can lead to disease, especially when the weather is cool. A layer of mulch can help keep the ground moist and also regulate the temperature of the soil. Stop watering your garlic a few weeks before you’ll harvest, when about half its leaves have turned brown.
Green onions are quick and easy to grow, and they really don’t require a lot of space. Provide your green onion plants with soil that isn’t too acidic and offers plenty of drainage, and mix in a two- or three-inch layer of compost for best results. Green onions grow best when the weather stays between 68 and 77 degrees Fahrenheit (20 to 25 degrees Celsius).
Space green onion plants between one inch and one and a half inches apart, at half an inch deep. It’s especially important for the ground to be consistently damp while seeds are sprouting and when the green onions are still young and immature. After that, provide them with 18 inches of water per week.
Kale is a cool-weather option that grows quite well in shallow containers, though it may never reach the monstrous sizes it can grow to when it has access to deeper soil. Plant in a soil that’s been blended with compost or manure to give plants the nitrogen they crave.
To grow baby kale, space plants one inch apart in rows set at four inches apart, or you can plant in a grid at two inches apart. To grow larger kale, provide plants with more space, consulting the seed packet or manufacturer instructions for specifics. Set seeds between a quarter of an inch and half an inch deep in a spot where they’ll get at least five hours of sun per day.
Once leaves are the size of your hand, simply trim them from the plant at the base, and other leaves will grow to replace them. Of course, you can wait for leaves to grow larger or harvest the whole plant at once if you prefer.
You don’t need a large container to grow lettuce, though for a shallow container, we’d recommend growing leaf lettuce instead of a Romaine, butterhead, or crisphead variety. Start planting in spring, and if you want a continuous harvest, plant again every 10 to 14 days. Use soil that has been treated with 5-10-10 fertilizer.
Plant 10 seeds per foot of container length at a depth of between a quarter of an inch or half an inch. Water in thoroughly after planting. Once seedlings have grown up a bit, thin them to stand four or five inches apart. Water the plants frequently, especially when plants are young, but use a light touch, as lettuce has shallow root systems. Place in a spot where plants will get at least six hours of sun each day.
With leaf lettuce varieties, you can use the “cut and come again” harvesting method to allow plants to regenerate after being harvested. Simply cut each leaf off individually at the base of the plant, working toward the inside and up, and allowing at least a third of the foliage to remain on the plant. New leaves will grow to take the place of the ones you remove.
Microgreens are so tiny, they can be grown in just about any container, no matter how shallow. You can purchase a microgreen seed mix or simply plant any salad green and harvest it at microgreen stage. Harvest microgreens when plants have their first true leaves (in about seven to 14 days) and measure between one inch and three inches tall.
Use seed-starting mix to almost fill your container, then sprinkle the microgreen seeds thinly over the seed starter. Top with a thin layer of the seed-starting mix, and water the seeds with a mist from a squirt bottle. Mist them like this to keep the ground moist; don’t let it become dry between rounds of misting, but don’t oversaturate the soil, either. Find a spot for your microgreens that offers plenty of sunlight.
Once the second set of leaves appear, it’s time to harvest. You can either snip off your microgreens just above the level of the soil, or you can pull them up roots and all.
You can grow mustard greens in the spring in USDA Hardiness Zones 6 to 11, or gardeners in zones 8 through 11 can grow them in fall. For a continuous harvest, keep sowing the seeds every two weeks.
Prepare soil for growing mustard greens with one of two amendments. You can either treat soil with an organic 10-10-10 fertilizer or by mixing in a two-inch layer of compost. Sprinkle the seeds over the treated soil, and mist them with a spray bottle to moisten but not waterlog the ground. Keep the ground moist and don’t let it become dry between watering sessions. You can add a layer of mulch once mustard plants are established to help the ground retain moisture and keep an even temperature.
When plants are between three and four weeks old, you can feed them with a 10-10-10 fertilizer blend, or you can use a seaweed or fish emulsion fertilizer. If you use granular fertilizer, make sure to water it in after application.
Use the “cut and come again” method to harvest your mustard greens by snipping off outer leaves from the base, working in and up. Leave at least one third of the leaves on the plant so it can keep growing, and it will replace the leaves you’ve harvested.
Radishes are a favorite garden plant because they’re so easy to grow, and they do well in shallow containers, too. Choose a spot for radishes that gets plenty of sun, or they’ll grow more greens than roots, and they won’t develop large radishes.
Choose a loose soil to maximize radish formation that includes plenty of organic material. Seeds should be placed an inch apart and between half an inch and one inch deep. While the weather stays cool in spring, you can keep planting more radishes every 10 to 12 days to extend your harvest. Thin plants to two inches apart when they’re about a week old.
Make sure the ground stays moist where radishes are growing, but don’t let it get oversaturated. You can use a thin layer of mulch to help keep moisture in the soil. Radishes are normally ready to harvest when you can see an inch of diameter in the roots at the surface of the soil. Just pull one up to check.
Another good veggie to grow in a shallow container is spinach. You can grow spinach practically year-round, though some varieties are better suited for winter while others grow best in the spring.
Plant your spinach seeds in soil with a pH level between 6.0 and 7.0. Containers should be at least six inches deep and should offer as much surface area as possible. Space your spinach plants between two and five inches apart, depending on how large you plan to let them grow before harvesting.
Water your spinach as soon as the soil where it’s growing seems to be going dry. Feed the plants regularly with a slow-release fertilizer. Keep spinach in a sunny spot, but when temperatures are higher than 80 degrees, provide it with some shade.
Harvest spinach when plants have at least five or six leaves, which is usually 40 to 45 days after it was planted. You can use cut-and-come-again harvesting to allow the plants to keep growing after harvest. Just make sure to leave at least a third of the leaves on the plant.
Swiss chard is an extremely nutritious vegetable that’s easy to grow in shallow containers. Just situate plants in a sunny spot, and give them rich soil that drains well.
Plant your chard three inches apart and half an inch deep. Once seedlings are a few inches tall, thin them out to stand 10 inches apart. Depending on the size of your container, you may choose to grow just one or two Swiss chard plants in each pot. Chard also does well tucked in with flowers in an ornamental garden.
Once plants have been growing for four to six weeks, you can harvest your Swiss chard. Use the cut-and-come-again method to remove outer leaves at the base, working your way inward and up. Just make sure to leave at least a third of the plant’s leaves intact so it will continue to grow.
Peppery watercress is another garden veggie that does well in shallow containers. Stack two containers together, or place one container in a tray. The bottom container will give watercress a constant supply of water.
Fill the top container with compost-rich soil. Add a few watercress starter plants, with roots attached, to the top container, then water them in well. Place this container on top of the one that you’ve filled with water. The water will soak up through the first container, keeping the soil moist so watercress can thrive.
Watercress does best when it gets several hours of sun each morning and shade in the afternoon. Snip off the leaves and allow the roots to stay planted, and your watercress will keep producing new leaves for several months.
As you can see, there’s no reason to feel like you can’t grow vegetables in shallow containers. You just need to select the plants you grow carefully to focus in on the plants that will thrive in shallower soil. With the options we’ve described, you can grow a thriving vegetable garden and keep your kitchen well stocked using solely shallow containers.
Learn More About Vegetables That Can Grow in Shallow Containers
Cynthia Beahm says
what are you considering a shallow container? how many inches?
Barbbette N. says
I too am confused. You cover a lot of details in your article but, other than Spinach, you skipped the topic. I already know how deep to sow seeds & bulbs but I was looking for, HOW DEEP should containers be???? Also, I disagree with Chard being on the list. Every year when I pull out the spent plants in the summer, I really have to pull hard because the tap root is a foot or more deep. One year I forgot to transplant one, from an 8″ tall pot, to my garden & the tap root went through the hole in the bottom of the pot & into the soil below.