Choosing Pots and Planters, and the Best Ones for Vegetables and Herbs

The right container does half the work of container gardening. A pot that is big enough, drains well and holds the right amount of moisture keeps roots healthy and saves you a watering a day in midsummer; the wrong one keeps you at the hose and still leaves plants struggling.

We picked the containers we would buy for a vegetable and herb patio: self-watering planters for thirsty crops, fabric grow bags for tomatoes and potatoes, classic terracotta for herbs that like it dry, and big lightweight planters for small trees and shrubs. The guide below explains how to choose by plant, size and material.

Size matters most

Most container problems are small-pot problems. Small pots dry out in hours on a hot day and leave roots no room. As a rule of thumb:

• Herbs, lettuce and other greens: 6 to 8 inches deep; a 1 to 3 gallon pot per herb.
• Peppers, eggplant, bush beans: 3 to 5 gallons per plant.
• Tomatoes: 5 gallons at the very least for a determinate variety, 10 to 20 gallons for an indeterminate one.
• Potatoes: 10 gallons or more; tall grow bags work well.
• Dwarf fruit trees and citrus: start at about 10 to 15 gallons and move up as they grow. See growing citrus trees in pots.

A pot too big for a small plant can stay wet for a long time, so for seedlings step up a size at a time.

Drainage is not optional

Every container needs drainage holes. Water that cannot leave the pot drowns roots and invites rot. The old advice to put gravel in the bottom of a pot does not help: it raises the soggy layer rather than draining it. Use a good potting mix instead (never garden soil, which compacts in a pot), and if you love a pot with no hole, use it as a decorative cover for a plastic pot that has one. Our guide to soil mixes for containers covers what to fill them with.

Materials, compared

• Terracotta is porous, so it breathes and dries out fast. It suits Mediterranean herbs (rosemary, thyme, sage, lavender) and succulents, and it is heavy enough not to tip. It can crack in hard freezes, so bring it in for winter in cold climates.
• Plastic and resin are light, cheap and hold moisture well, which suits thirsty vegetables. Pick a light color for sunny spots, as dark plastic heats the root zone.
• Glazed ceramic looks good and holds moisture, but it is heavy and can crack in frost.
• Fabric grow bags let excess water drain and air prune roots, which avoids circling roots. They dry out faster than plastic and fold flat for winter.
• Metal looks sharp but heats up quickly in sun; use it in shade or with a liner.
• Wood insulates roots well; choose a naturally rot-resistant wood such as cedar, and avoid old treated timber for food crops.

When self-watering pots are worth it

Self-watering planters have a reservoir under the soil, and roots or a wicking chamber draw water up as the plant needs it. They are worth it for thirsty crops such as tomatoes, peppers, cucumbers and greens on a sunny patio, and for anyone who cannot water every day. They are less suited to plants that like to dry out between waterings, like rosemary or succulents. Fertilizer matters more in them, because nutrients are not flushed through; see fertilizing container plants, and our basics of container gardening for the rest.

Frequently asked questions