Start with soil, not seeds

Fill your raised bed with a mix of topsoil, compost, and peat moss or coconut coir in roughly equal parts. This blend drains better than garden soil alone and gives vegetables the loose, nutrient-rich medium they need to establish roots. Do not use soil from your yard — it compacts in a raised bed and often carries weed seeds and disease.

The bed should be filled to within two inches of the top. Water the soil thoroughly after filling and let it settle for a day or two before planting. Soil that is bone-dry will repel water when you first plant, so dampen it before you add seeds or seedlings.

Key Takeaways

  • Fill your raised bed with a 1:1:1 mix of topsoil, compost, and peat moss or coconut coir rather than garden soil alone.
  • Plant seeds directly into the soil at the depth listed on the seed packet, or transplant seedlings started indoors at the same depth they were growing in their containers.
  • Space plants according to the packet instructions — crowding reduces air flow and invites disease and pest problems.
  • Water at the soil level in the early morning, aiming to keep the top inch moist but not waterlogged.
  • Most vegetables need six to eight hours of direct sunlight daily, so position your bed where it receives sun from mid-morning through afternoon.

Decide between seeds and seedlings

Seeds are cheaper and give you more variety, but they take longer to produce a harvest. Seedlings (also called transplants) cost more but are ready to produce sooner. For a first raised bed, a mix of both works well — start fast-growing leafy greens and root vegetables from seed, and buy seedlings of tomatoes, peppers, and eggplant, which take weeks to reach transplant size indoors.

If you choose seeds, read the packet for the planting depth — most seeds go in at a depth equal to twice their width. Tiny seeds like carrot and lettuce barely get covered; larger seeds like beans and squash go in deeper. Plant seeds in rows or clusters depending on the spacing the packet recommends.

If you buy seedlings, harden them off first by setting them outside in a sheltered spot for an hour or two, then gradually increasing their time outside over five to seven days. This prevents transplant shock. Plant them at the same depth they were growing in their containers — burying the stem deeper can cause rot.

Space plants to prevent crowding

Crowded plants compete for water and nutrients, and poor air flow invites mildew and fungal disease. Follow the spacing on the seed packet or the label on your seedling. Lettuce and spinach typically need four to six inches between plants; tomatoes and peppers need 18 to 24 inches; beans and squash need 12 inches or more.

In a raised bed, you can plant more densely than in a garden row because the soil is richer and you can water more precisely. But do not treat the spacing as a suggestion — it exists because plants need room to grow. A four-inch lettuce seedling will be 12 inches wide at maturity.

Water at soil level in the morning

Water the soil directly, not the leaves. Wet foliage invites fungal disease, especially in warm, humid weather. Water early in the morning so any moisture that does land on leaves dries quickly as the sun rises.

Raised beds drain faster than in-ground gardens, so check the soil moisture every day during hot weather. Stick your finger into the soil an inch deep — if it feels dry, water. The goal is to keep the top inch moist but not waterlogged. Overwatering is as harmful as underwatering; it suffocates roots and promotes rot.

A soaker hose or drip line laid along the soil surface delivers water slowly and directly to the roots. If you use a watering can or hose, aim for the base of each plant and avoid splashing the leaves.

Position the bed for six to eight hours of sun

Most vegetables need at least six hours of direct sunlight daily. Tomatoes, peppers, squash, and beans want eight or more. Leafy greens like lettuce and spinach tolerate partial shade and can actually benefit from afternoon shade in very hot climates.

Before you fill the bed, observe the spot throughout the day. Note where the sun hits in early morning, midday, and late afternoon. A bed that gets morning sun and afternoon shade is often ideal in hot regions; a bed with sun from mid-morning through late afternoon works well in cooler climates.

Add compost or fertilizer as plants grow

The soil you mixed at the start will feed your plants for the first four to six weeks. After that, nutrients begin to deplete, especially for heavy feeders like tomatoes, peppers, and squash. Side-dress plants with compost — scatter a one-inch layer of finished compost around the base of each plant, keeping it an inch or two away from the stem.

Alternatively, use a balanced vegetable fertilizer mixed to package strength every two to three weeks. Organic options include fish emulsion, seaweed extract, and composted manure tea. Follow the label instructions for the amount and frequency.

Manage weeds and pests as they appear

Raised beds have fewer weeds than in-ground gardens because the soil is contained, but they still appear. Pull them by hand when they are small — the loose soil makes this straightforward. Do not let them flower and set seed, or you will have more next year.

Watch for common pests like aphids, spider mites, and hornworms. Spray affected plants with water from a hose to dislodge soft-bodied insects. For persistent problems, neem oil or insecticidal soap work on most vegetable pests. Hand-pick larger insects like hornworms and beetles. Encourage beneficial insects like ladybugs and parasitic wasps by planting flowers nearby — marigolds, zinnias, and alyssum all attract them.

Frequently Asked Questions

Can I plant vegetables directly next to each other with no space between them?

No. Crowded plants shade each other, compete for water and nutrients, and create humid conditions that invite disease. Follow the spacing on the seed packet or seedling label. You can plant densely compared to a garden row, but not touching.

What if my raised bed gets only four hours of sun?

Grow leafy greens, herbs, and root vegetables like lettuce, spinach, kale, parsley, and beets. Avoid tomatoes, peppers, squash, and beans — they need more light to produce well. Some herbs like mint and parsley actually prefer afternoon shade in hot climates.

How often should I water a raised bed?

Check the soil daily by inserting your finger one inch deep. Water when the top inch feels dry. In hot weather this may be daily; in cool weather it may be every two to three days. The goal is moist soil, not soggy. Overwatering causes root rot and fungal disease.

Do I need to replace the soil every year?

No. Mix in two to three inches of compost at the start of each season to replenish nutrients and organic matter. After three to five years, the soil may compact enough that you should replace the top six inches. Complete replacement is rarely necessary if you add compost regularly.

Can I plant in fall as well as spring?

Yes. Cool-season crops like lettuce, spinach, kale, broccoli, and carrots grow well in fall and winter in most climates. Plant them eight to ten weeks before your first frost date so they mature before hard freezes arrive. Spring planting works for warm-season crops like tomatoes, peppers, and squash.