Most vegetables, herbs, and shallow-rooted fruits thrive in raised beds

A raised bed works for nearly any plant you'd grow in the ground, as long as the soil depth matches what the plant needs. Tomatoes, peppers, lettuce, carrots, beans, squash, and herbs all produce well in raised beds because you control the soil quality and drainage. The main limit is root depth — plants that need more than 24 inches of soil (like standard fruit trees) struggle unless your bed is built tall enough, but most common garden plants do fine in 12 to 18 inches.

What grows best depends on three things: how deep your bed is, how much sun it gets, and what you're willing to tend. A shallow bed (8 to 12 inches) works for lettuce, spinach, radishes, and herbs. A standard bed (12 to 18 inches) handles most vegetables. A deep bed (18 to 24 inches or more) opens up root vegetables like parsnips and potatoes, plus perennial herbs like asparagus.

Key Takeaways

  • Leafy greens, herbs, and shallow-rooted vegetables like lettuce and radishes grow in beds as shallow as 8 inches.
  • Most common vegetables—tomatoes, peppers, beans, squash, and carrots—need 12 to 18 inches of soil and produce reliably in standard raised beds.
  • Root vegetables like potatoes and parsnips, plus perennial herbs like asparagus, require 18 to 24 inches of depth to develop properly.
  • Full sun (6 to 8 hours daily) is necessary for fruiting plants like tomatoes and peppers, but leafy greens tolerate partial shade.

Vegetables that grow well in 12 to 18 inches of soil

This is the sweet spot for most home gardeners. Tomatoes (both determinate and indeterminate varieties), peppers, eggplant, zucchini, summer squash, green beans, snap peas, and cucumber all produce well at this depth. Leafy crops like lettuce, spinach, arugula, and kale are even easier—they're forgiving of soil depth and grow fast. Carrots, beets, and turnips work here too, though they'll be smaller than in deeper soil.

The key is spacing. A 4-by-8-foot bed at 18 inches deep can hold one large tomato plant and one pepper plant comfortably, or six to eight lettuce plants, or a full row of beans. Crowding plants leads to poor air circulation, which invites disease. Check the seed packet or plant tag for spacing—it's usually the most reliable guide.

Herbs that thrive in raised beds

Herbs are among the easiest raised bed crops because most need only 8 to 12 inches of soil. Basil, parsley, cilantro, dill, chives, oregano, thyme, and sage all do well. Plant them at the edge of a bed so you can harvest without stepping over other plants, or dedicate a shallow bed to herbs alone.

Perennial herbs—ones that come back year after year—include oregano, thyme, sage, chives, and lavender. They'll occupy the same spot for three to five years, so plant them where they won't be disturbed by annual vegetable rotations. Annual herbs like basil and cilantro finish in one season and need replanting.

Root vegetables and why depth matters

Carrots, beets, parsnips, and potatoes need room for roots to expand downward. Carrots in shallow soil fork or twist; potatoes in 12 inches of soil produce small tubers. A bed 18 to 24 inches deep gives these crops the space they need. Radishes are the exception—they're ready in 30 days in just 6 inches of soil and are good for filling gaps between slower crops.

Potatoes are worth mentioning separately because they're often grown in raised beds using a "hilling" method. You plant seed potatoes 4 inches deep, then add more soil as the plant grows, burying the stem. This works well in a deep bed and can increase your yield in the same footprint.

Fruiting plants and sun requirements

Tomatoes, peppers, eggplant, squash, and cucumber all need full sun—at least 6 to 8 hours of direct sunlight daily. Without it, they flower poorly and produce little fruit. If your bed gets less than 6 hours, choose leafy greens, herbs, or shade-tolerant crops like lettuce and spinach instead. Partial shade (3 to 6 hours) is enough for these.

Raised beds warm up faster in spring than ground soil, which helps fruiting plants get an earlier start. They also drain better, reducing the root rot risk that comes with wet soil. This is one reason tomatoes and peppers do so well in raised beds even in rainy climates.

Perennial crops and permanent plantings

Most raised beds are replanted each year, but some crops stay put. Asparagus, rhubarb, and perennial herbs occupy the same space for years. If you want a permanent herb bed, dedicate one raised bed to oregano, thyme, sage, and chives, and leave it undisturbed. Asparagus needs 18 to 24 inches of depth and produces for 15 to 20 years once established, so it's worth the investment in a deep bed.

Keep perennials separate from annuals. Tilling or amending an annual vegetable bed in spring will damage asparagus roots or rhubarb crowns. If space is tight, use containers for perennial herbs instead.

What doesn't work in raised beds

Standard fruit trees (apple, peach, pear) need more root depth than a raised bed can provide—they'll be stunted or short-lived. Dwarf or genetic dwarf varieties bred for containers can work in very deep beds (24 inches or more), but they're not typical raised bed plants. Corn is possible but awkward—it needs space and wind pollination, and a raised bed usually isn't the best use of that space.

Watermelon and cantaloupe sprawl across a bed and shade out neighbors, so they're better in their own dedicated space or in-ground. If you have room and want to try them, give them a full 4-by-8-foot bed to themselves.

Frequently Asked Questions

Can I grow potatoes in a raised bed that's only 12 inches deep?

Yes, but you'll get smaller potatoes. Potatoes develop tubers along the buried stem, so deeper soil means more room for larger potatoes. At 12 inches, expect golf-ball to tennis-ball sized potatoes. If you want full-sized potatoes, aim for 18 to 24 inches and use the hilling method—add soil as the plant grows.

What's the minimum sun for tomatoes in a raised bed?

Tomatoes need at least 6 to 8 hours of direct sun daily to flower and fruit well. Less than 6 hours and you'll get lots of leaves but few tomatoes. If your bed gets 4 to 6 hours, choose determinate (bush) varieties, which are more forgiving than indeterminate (vining) types.

Can I grow lettuce and tomatoes in the same raised bed?

Yes, if you plant lettuce early in spring and harvest it before tomatoes get large. Lettuce grows fast (30 to 60 days) and is shade-tolerant, so it can grow in the shadow of a young tomato plant. Once the tomato is full-sized, the lettuce will be gone. Don't try to grow them side by side all season.

How deep does a raised bed need to be for carrots?

Carrots need at least 12 inches, ideally 18 inches. Short varieties like 'Nantes' and 'Chantenay' work in 12 inches. Long varieties like 'Imperator' need 18 inches or they'll fork or twist. Check the seed packet for the mature length of the variety you choose.

Can I grow garlic or onions in a raised bed?

Yes. Garlic and onions need 12 inches of soil and are low-maintenance. Plant garlic cloves in fall (October or November in most climates) and harvest in summer. Plant onion sets or transplants in early spring. Both tolerate partial shade and don't need much fertilizer, making them good choices for beginner gardeners.