Container Size Guide

The right container depends on the mature plant, not the small seedling you bring home. A suitable pot gives roots room, holds useful moisture, drains extra water, and stays stable as the plant grows.

Use the crop's minimum size

The cards below show the saved minimum pot size when the crop guide has one. Treat it as a starting point. A larger container may dry more slowly, but it also becomes heavier and needs more potting mix.

• 

  Easy

  Basil

  A tender summer herb that grows fast, hates cold nights, and gives more the more often you cut it.

  • Full sun
  • 50 to 75 days
  • 2 gal pot or bigger
  • 6 to 12 in apart
• 

  Takes some care

  Bell Pepper

  A sweet, warm-season pepper that can be picked green or left to ripen to its final color.

  • Full sun
  • 70 to 85 days
  • 5 gal pot or bigger
  • 18 in apart
• 

  Takes some care

  Chili Pepper

  A warm-season pepper grown for pods that range from gently warm to very hot.

  • Full sun
  • 70 to 120 days
  • 5 gal pot or bigger
  • 12 to 24 in apart
• 

  Easy

  Cilantro

  A cool-weather herb with fresh leaves called cilantro and dried seeds called coriander.

  • Full sun
  • 45 to 80 days
  • Grows in a pot
  • 3 to 6 in apart
• 

  Takes some care

  Cucumber

  A warm-season vine grown for crisp green fruit that is picked before it turns yellow.

  • Full sun
  • Grows in a pot
  • 8 to 12 in apart
• 

  Easy

  Green Beans

  A warm-season crop picked while the pods are crisp and the seeds inside are still small.

  • Full sun
  • 50 to 60 days
  • Grows in a pot
  • 3 to 4 in apart
• 

  Easy

  Green Onion

  An onion grown for its mild green stalks and small white base instead of a dry storage bulb.

  • Full sun
  • Grows in a pot
  • 2 to 4 in apart
• 

  Easy

  Kale

  A cold-tough leafy green that can keep making harvests well into fall.

  • Full sun
  • Grows in a pot
  • 8 to 12 in apart
• 

  Easy

  Lettuce

  A fast, cool weather leaf crop that you can pick from for weeks. It is at its best in spring and autumn, and turns bitter in a hot, dry spell.

  • Part sun
  • 50 to 70 days
  • 1 gal pot or bigger
  • 5 to 12 in apart
• 

  Easy

  Mint

  A quick-growing perennial herb for drinks, cooking and tea. Grow it in a pot because its creeping roots spread fast.

  • Part sun
  • Grows in a pot
  • 18 in apart
• 

  Easy

  Parsley

  A leafy herb with slow-sprouting seed and a long harvest season once established.

  • Full sun
  • Grows in a pot
  • 10 to 12 in apart
• 

  Easy

  Peas

  A cool-season vine grown for sweet seeds or tender edible pods.

  • Full sun
  • 55 to 70 days
  • Grows in a pot
  • 1 to 3 in apart

Drainage is not optional

Choose a container with a way for extra water to leave. Fill it with a light potting mix that holds moisture while still allowing air and water to move. Ordinary garden soil is often too heavy for a container.

A container still needs an open path for drainage. If water cannot leave the pot, roots can lose the air they need.

Plan for weight before filling

A large container filled with wet mix and plants can be very heavy. Choose its final spot first. On a balcony or deck, check the safe load and plan where drainage water will go. Use a plant caddy before filling if the pot must move.

Match the plant's shape

Bush, dwarf, and compact varieties are often easier in small spaces. A fruiting or fast-growing plant may also need a stake or trellis so it does not become top-heavy. Add support early to avoid damaging crowded roots later.

Check water more often

Containers dry faster than garden soil. Check the mix often during heat and wind, then water thoroughly when it begins to dry. Pot size alone cannot set a watering schedule because the crop, weather, mix, sun, and plant size all matter.

Sources

• Growing Vegetables in Containers (University of Maryland Extension)
• Growing Vegetables In Containers (University of New Hampshire Extension)