Fill your bed with soil, then plant at the depth and spacing each vegetable needs

Planting in a raised bed is straightforward: fill the bed with soil, space your plants according to their mature size, and plant at the correct depth. Most vegetables go in at the same depth they were growing in their nursery pot, with the soil line on the stem staying at the same level. Root crops like carrots and beets go deeper — their seed packets say how deep. Leafy greens and herbs can go closer together than tomatoes or peppers because they take up less space when full-grown.

The main difference from ground planting is that raised beds warm up faster in spring and dry out faster in summer, so you may need to water more often. The soil you use matters: a mix of topsoil, compost, and peat moss or coconut coir works better than garden soil alone, which compacts. If you are starting with an empty bed, fill it completely before planting — do not add soil as you go.

Key Takeaways

  • Plant at the same depth the seedling was growing in its pot, except for root crops which go deeper according to the seed packet.
  • Space plants based on their mature size, not their current size — a tomato seedling looks small but needs 24 to 36 inches from its neighbors.
  • Fill the entire bed with soil before planting rather than adding soil around each plant as you go.
  • Water raised beds more often than ground gardens because they drain and warm faster, especially in hot weather.
  • A mix of topsoil, compost, and peat moss or coconut coir holds moisture and nutrients better than topsoil alone.

Measure spacing before you plant

Spacing is the most common mistake in raised beds. A seedling that is 3 inches tall will be 24 inches wide when it matures, but it does not look like it yet. Before you plant anything, read the seed packet or plant label — it will say "space 24 inches apart" or "thin to 12 inches." That number is the distance from the center of one plant to the center of the next.

For a 4-by-8-foot bed, you can fit roughly four tomato plants (spaced 24 inches apart), or nine pepper plants (spaced 18 inches apart), or sixteen lettuce plants (spaced 12 inches apart). If you crowd them, the plants compete for water and nutrients, leaves stay wet longer and invite disease, and you get smaller harvests. It is better to plant fewer and get more from each one.

Some gardeners use a grid method: mark the bed with string or chalk in a grid pattern matching your spacing, then plant at each intersection. This takes a few minutes but prevents the guesswork and the regret later.

Plant at the correct depth

Most seedlings go in at the same depth they were growing in their nursery pot. Look at the stem — there is usually a soil line showing where the soil reached. Plant so that line is at the same level in your raised bed. Burying the stem deeper can cause rot; planting too shallow leaves roots exposed.

Tomatoes are an exception: they can go deeper than they were growing, even up to the first true leaves. Tomato stems will grow roots along their buried length, which strengthens the plant. Peppers, eggplants, and most other vegetables should stay at their original depth.

Root crops — carrots, beets, parsnips, radishes — are started from seed, not seedlings. The seed packet tells you how deep to plant: usually one-quarter to one-half inch for small seeds, one inch for larger ones. Plant in rows or scattered, then thin seedlings once they sprout to the spacing the packet says.

Water when ready after planting

Water the bed thoroughly right after you plant. This settles the soil around the roots and removes air pockets that can dry out new roots. Water until the soil is moist 6 inches deep — you can check by pushing a finger into the soil or using a soil moisture meter.

Raised beds dry out faster than ground gardens because they have more surface area and drain more freely. In hot weather, you may need to water every day or every other day, especially if the bed is in full sun. Check the soil before watering — if the top inch is still moist, wait. If it is dry, water deeply rather than sprinkling lightly.

Plant in rows or blocks depending on your bed size

In a narrow bed (2 to 3 feet wide), plant in single or double rows running the length of the bed. This makes it straightforward to reach plants from either side without stepping on the soil. In a wider bed (4 feet or more), you can plant in blocks or a grid pattern, leaving a path down the middle so you can reach the center without stretching.

For a 4-by-8-foot bed, plant three rows of leafy greens running lengthwise, or two rows of tomatoes with a path between them. The layout depends on what you are growing and how much you want to harvest at once. Tall plants like tomatoes and beans should go on the north side of the bed so they do not shade shorter plants.

Succession plant to spread out your harvest

You do not have to plant everything on the same day. Lettuce, spinach, beans, and squash grow fast enough that you can plant a new batch every two to three weeks and have a steady harvest instead of everything ripening at once. This is called succession planting.

Mark on a calendar when you planted each crop, then plant the next batch when the first one is up and growing well. For cool-season crops like lettuce and peas, stop planting when the weather gets hot — they bolt and turn bitter. Start again in late summer for a fall crop. For warm-season crops like beans and squash, you can plant every three weeks from late spring until eight weeks before your first frost date.

Amend the soil as plants grow

Raised beds lose nutrients as plants grow and as you harvest. By midsummer, the soil is less rich than it was in spring. Add compost or aged manure around the base of plants (not touching the stem) every four to six weeks, or use a balanced fertilizer if you prefer. Compost feeds the soil and improves its structure; fertilizer feeds the plants directly.

If you are growing heavy feeders like tomatoes, peppers, or squash, they benefit from extra nitrogen early in the season and extra phosphorus and potassium once they start flowering. A slow-release fertilizer mixed into the soil at planting time, or fish emulsion or seaweed spray every two weeks, keeps them fed without burning the leaves.

Frequently Asked Questions

Can I plant seeds directly in a raised bed or do I need seedlings?

You can plant either. Seeds are cheaper and work well for root crops, beans, squash, and leafy greens. Seedlings are faster and better for tomatoes, peppers, and eggplants in short growing seasons. Start seeds indoors six to eight weeks before your last frost date, or direct-seed outdoors once the soil is warm enough — the seed packet says when.

How deep should a raised bed be for vegetables?

Most vegetables need 8 to 12 inches of soil. Root crops like carrots and parsnips need 12 inches or more so their roots have room to grow. Shallow-rooted crops like lettuce and herbs can grow in 6 inches. If your bed is shallower, stick to leafy greens and herbs.

What is the best soil mix for a raised bed?

A mix of one-third topsoil, one-third compost, and one-third peat moss or coconut coir holds moisture and nutrients well. You can also use a bagged "raised bed mix" from a garden center. Avoid pure garden soil, which compacts; avoid pure compost, which drains too fast and settles over time.

Should I plant in rows or a grid pattern?

Either works. Rows are easier in narrow beds; a grid is easier in wide beds where you need to reach the center. Choose based on your bed size and what you are growing. Tall plants like tomatoes should run north to south so they do not shade shorter plants.

How often should I water a raised bed?

Check the soil before watering — if the top inch is dry, water deeply. In hot weather, this may be every day. In cool weather or after rain, you may not need to water for several days. Raised beds drain faster than ground gardens, so they usually need more frequent watering, especially in summer.