Start with what your space and soil can handle

The best crops for a raised bed depend on three things: how deep your bed is, how much sun it gets, and what you actually want to eat. A bed that is 6 inches deep works for lettuce and herbs. A bed that is 12 inches deep handles tomatoes, peppers, and root vegetables. A bed that is 18 inches or deeper gives you room for anything — including deep-rooted plants like carrots and potatoes that need real soil underneath them.

Full sun (6 to 8 hours of direct light per day) grows tomatoes, peppers, squash, beans, and cucumbers. Partial shade (3 to 6 hours) works for lettuce, spinach, kale, and other leafy greens. If your bed gets less than 3 hours of sun, herbs like mint, parsley, and chives are your best bet, along with shade-tolerant greens.

The soil itself matters more than the bed. Raised beds drain faster than ground soil, so they dry out quicker in summer. If your bed is in a hot, windy spot, you will water more often. If it is sheltered and gets afternoon shade, you will water less. Start by watching how your soil behaves for a week or two before deciding what to plant.

Key Takeaways

  • Shallow beds (6 inches) grow lettuce, herbs, and radishes; deeper beds (12 to 18 inches) are needed for tomatoes, peppers, and root crops like carrots.
  • Tomatoes, peppers, squash, and beans need 6 to 8 hours of direct sun; leafy greens and herbs tolerate partial shade or less light.
  • Raised beds drain quickly, so plants that prefer consistent moisture (like lettuce) may need more frequent watering than the same plants in ground soil.
  • Cool-season crops like spinach, kale, and peas grow in spring and fall; warm-season crops like tomatoes and peppers go in after the last frost date.
  • Succession planting — sowing lettuce or beans every two weeks — keeps a single bed producing from spring through fall.

Vegetables that produce heavily in raised beds

Tomatoes are the most popular raised bed crop because they need good drainage and benefit from the warmer soil a raised bed provides. Cherry tomatoes and determinate varieties (bush types) work better than sprawling heirlooms in a confined space. You will need stakes or cages, and the bed should be at least 12 inches deep.

Peppers — both sweet and hot — thrive in raised beds and need the same depth as tomatoes. They are slower to produce than tomatoes but keep bearing until frost. They like warmth, so wait until the soil is genuinely warm (not just the air) before planting.

Lettuce and leafy greens (spinach, kale, arugula, chard) are the easiest crops for a beginner. They grow in 6 inches of soil, tolerate partial shade, and are ready to harvest in 30 to 60 days. You can plant them in early spring, again in midsummer for a fall crop, and sometimes even in late fall in mild climates.

Beans (both bush and pole varieties) fix nitrogen in the soil, so they improve it for the next crop. Bush beans need 6 inches of depth; pole beans need support but produce more per square foot. Plant them after the soil warms up, usually 2 to 3 weeks after your last frost date.

Squash and zucchini take up space but produce heavily. A single plant can feed a family. They need 12 inches of depth, full sun, and consistent water. Plant them in late spring after all frost danger has passed.

Root vegetables and what depth they actually need

Root crops are where bed depth matters most. Radishes are done in 30 days and need only 4 inches of soil. Beets need 6 inches. Carrots need 8 to 12 inches depending on the variety — short varieties like 'Nantes' work in shallow beds, but long varieties like 'Imperator' need the full depth. Potatoes technically need 12 inches, but many gardeners grow them in bags or containers within the bed to save space.

The reason depth matters is that a carrot or potato forced to grow sideways because it hits the bottom of the bed will fork or twist. If your bed is only 8 inches deep, stick to short carrot varieties and skip the long ones. Beets are forgiving — they will grow smaller if the bed is shallow, but they will still produce.

Root vegetables also prefer loose, well-draining soil. If your raised bed has heavy clay mixed in, roots will struggle. If you are starting from scratch, fill the bed with a mix of topsoil and compost rather than pure compost, which compacts over time.

Herbs that thrive in raised beds year-round

Basil is an annual that dies at the first frost, but it grows fast and produces all summer. Plant it after the soil warms up. Parsley, cilantro, and chives are cold-hardy and can stay in the bed through fall and sometimes winter, depending on your climate. Mint spreads aggressively, so plant it in a pot buried within the bed, or it will take over.

Herbs need less depth than vegetables — 6 inches is usually enough. They also tolerate partial shade better than fruiting crops. If your bed gets afternoon shade in summer, herbs are a good use of that space. Most herbs prefer soil that is not constantly wet, so raised beds are ideal because they drain well.

Perennial herbs like thyme, oregano, and sage can stay in the bed year after year. They are tougher than annuals and need less water once established. If you live in a cold climate, mulch around them in fall to protect the roots.

Timing: what to plant when

Cool-season crops go in as soon as the soil can be worked in spring — usually 2 to 4 weeks before your last frost date. This includes lettuce, spinach, peas, and radishes. They grow fast, mature before summer heat arrives, and can be replanted in late summer for a fall crop.

Warm-season crops (tomatoes, peppers, squash, beans, basil) go in after your last frost date, when the soil has warmed to at least 60°F. Planting too early means the seeds will sit in cold soil and rot. If you are impatient, start seeds indoors 6 to 8 weeks before your frost date and transplant seedlings into the bed after the danger has passed.

In mild climates (zones 8 and warmer), you can plant cool-season crops in fall and harvest through winter. In cold climates, the bed sits empty or holds only cold-hardy greens from November through March. Check your local frost dates — they vary by region and even by neighborhood.

Succession planting to keep the bed productive

Instead of planting everything at once and harvesting everything at once, sow lettuce, beans, or radishes every two weeks. This spreads the harvest across the season and means you are not overwhelmed with ripe tomatoes in August and nothing in September.

After a cool-season crop like peas or lettuce finishes in early summer, pull it out and plant a warm-season crop like beans or squash in the same space. After that crop finishes in fall, plant another round of lettuce or spinach for a late-season harvest. A single bed can produce three or four different crops in one year if you plan it right.

Keep a straightforward calendar: write down what you planted, when you planted it, and when you harvested it. After one season, you will know exactly what works in your bed and what does not.

What not to plant in a shallow raised bed

Do not plant long-rooted crops (like full-size carrots or parsnips) in a bed shallower than 12 inches. Do not plant trees or large shrubs — raised beds are temporary structures, and trees will outlive them. Do not plant aggressive spreaders like mint or bamboo without containing them first.

Avoid planting the same crop in the same bed year after year. Tomatoes, peppers, and potatoes are all in the nightshade family and deplete the same nutrients. Rotate them to a different bed or add compost and fertilizer to replace what was used. If you have only one bed, plant something from a different family the next year — lettuce after tomatoes, beans after peppers.

Frequently Asked Questions

Can I grow tomatoes in a 6-inch-deep raised bed?

No. Tomatoes need at least 12 inches of soil depth to develop a strong root system. In shallow soil, they will be stunted and produce poorly. If your bed is only 6 inches deep, grow lettuce, herbs, or radishes instead.

How often do I water plants in a raised bed?

Raised beds drain faster than ground soil, so you will water more often — sometimes daily in hot weather. Check the soil 2 inches down; if it is dry, water. In spring and fall, you may water only once or twice a week. Mulching the bed with 2 inches of compost or straw helps retain moisture.

What if my raised bed gets only 3 to 4 hours of sun?

Grow leafy greens (lettuce, spinach, kale), herbs (parsley, mint, chives), and shade-tolerant crops. Avoid tomatoes, peppers, and squash, which need 6 to 8 hours of direct sun to produce well. Partial shade actually helps lettuce stay tender in summer heat.

Can I plant the same vegetables in the same bed every year?

You can, but soil quality will decline and pests and diseases will build up. Rotate crops by plant family: follow tomatoes with lettuce or beans, not peppers or potatoes. If you must replant the same crop, remove the top 4 inches of soil and replace it with fresh compost.

When should I start seeds indoors for a raised bed?

Start warm-season crops (tomatoes, peppers, squash) indoors 6 to 8 weeks before your last frost date. Start cool-season crops (lettuce, spinach) indoors 4 to 6 weeks before planting them outside. Check your local frost date to know when to transplant seedlings into the bed.