Growing vegetables in containers

Last reviewed September 2026 · written from public-domain USDA/NOAA data and Cooperative Extension references — see how we source data

Illustration of a sunny balcony container garden: a staked tomato in a large pot, a pepper plant with red and yellow fruit, lettuce and basil in smaller pots, in front of a metal railing.

A container garden trades some yield and root room for the ability to grow vegetables anywhere with a few hours of sun — a balcony, a patio, a driveway. The two things that make or break it are the right pot size and the right soil.

What grows well in a pot

Herbs, lettuce and other greens, bush beans, radishes, and compact or "patio" varieties of tomatoes, peppers and cucumbers all do well. Full-size sprawling vines, sweet corn and main-crop potatoes need more root run and space than most containers give.

Choose container varieties

The biggest single improvement is picking varieties bred for small spaces. Look for "patio", "bush", "dwarf", "compact" or "determinate" on the seed packet or plant label - a determinate patio tomato stays around two to three feet, while an indeterminate one wants to reach six or more.

Bush beans rather than pole beans, round or short carrots rather than long ones, and loose-leaf lettuce that you pick leaf by leaf all give far more from a pot than their full-size relatives.

Sizing the container

Roughly: one gallon for a single herb, five gallons for peppers or a dwarf tomato, ten to fifteen-plus gallons for a full-size tomato plant. Bigger is more forgiving of missed watering. Every container needs drainage holes — without them, roots sit in water and rot.

How deep a container each crop needs

1-2 gal

6″ deep lettuce, spinach, radish, arugula, green onion, thyme, mache, tatsoi, mizuna, watercress

2-3 gal

8″ deep bush bean, onion, garlic, basil, cilantro, bok choy, mustard greens, oregano, mint, endive & escarole, shallot, rapini and 3 more

3-5 gal

10-12″ deep bell pepper, chili pepper, cucumber, pole bean, pea, kale, swiss chard, broccoli, cauliflower, cabbage, carrot, beet and 27 more

10-15 gal

14-16″ deep tomato, zucchini, potato, eggplant, okra, brussels sprouts, parsnip, sweet potato, tomatillo, sunflower, bitter melon, peanut

15-25 gal

18″+ deep salsify

Minimum depth of potting mix from our crop database; the gallon figures are a rough guide to a matching pot for one plant (or a small group of greens and herbs). Go bigger whenever you can - more mix means more water held and fewer wilted afternoons. Not suited to containers: winter squash, pumpkin, sweet corn, watermelon, asparagus, rhubarb, chayote, luffa.

Use potting mix, not garden soil

Garden soil compacts hard in a container, drains poorly, and can carry soil-borne disease. A bagged soilless potting mix (mostly peat or coir, perlite and compost) stays light and drains while still holding moisture.

Pot material and colour

Terracotta looks good but is porous and dries out fastest. Plastic and glazed pots hold moisture longer. Fabric grow bags drain and breathe well, which roots like, but they also dry out quickly in heat.

Dark pots in full sun can cook the roots on one side. Group pots so they shade each other, or set a smaller pot inside a larger, lighter-coloured one. Self-watering containers with a reservoir take a lot of the daily pressure off in summer.

Sun, wind and placement

Fruiting crops still need six to eight hours of direct sun; leafy greens and herbs manage with four to six. Balconies are often windier than they look, and wind dries pots out much faster - a screen or a sheltered corner helps.

A wall that faces the afternoon sun reflects a lot of heat. That helps peppers and eggplant in a cool climate but can scorch lettuce, so move pots to follow the season.

Watering and feeding more often

Containers dry out far faster than ground beds — daily watering in summer heat is normal, sometimes twice a day for small pots. Frequent watering also washes nutrients out the drainage holes faster, so feed more often, typically at half the label strength every one to two weeks rather than a big monthly dose.

Common container problems

Wilting every afternoon even when watered in the morning usually means the pot is too small for the plant. Move it up a size or water twice a day in heat waves.

Yellowing lower leaves mean nutrients have washed out - feed more regularly (nitrogen deficiency). Blossom-end rot is common in pots because the mix swings between dry and wet; steady watering is the fix (blossom-end rot explained).

Common questions

What vegetables grow best in containers?

Lettuce and other salad greens, herbs, radishes, bush beans, peppers, patio tomatoes, and bush cucumbers or zucchini in large pots. Sprawling winter squash, pumpkins, sweet corn and watermelon need more space than a container gives.

What size pot does a tomato need?

A full-size tomato needs at least 10-15 gallons and about 16 inches of depth. Dwarf and patio varieties manage in 5 gallons. Bigger pots hold more water, so they are far more forgiving on hot days.

Can I reuse potting soil?

Yes, if the plants in it were healthy. Remove old roots, mix in about a quarter fresh compost, and add a slow-release fertilizer. Replace it if the previous crop had a soil-borne disease such as fusarium or blight.

How often should I water container vegetables?

Check every day in summer by pushing a finger an inch or two into the mix, and water when it feels dry. In hot weather most pots need water daily and small ones may need it twice. Water until it drains from the bottom.