How Do You Plan a Raised Bed Garden?
Plan a raised bed garden in five steps: measure the bed and its sun, choose crops you will eat, place tall crops on the north side, space everything by the square, and check neighbors for companion conflicts. Then time each sowing from your average last frost date.
Start with the space: a vegetable bed needs at least 6 hours of direct sun, and fruiting crops such as tomatoes, peppers and squash do best with 8. Count the squares — a 4 × 8 ft bed has 32 — and decide how many go to each crop before buying seed. Large plants cost the most room: one zucchini takes about 4 squares, the same space as 64 carrots.
Pick one of the templates in the planner or start from an empty bed, tap a crop, then tap squares. The plant list totals every bed and turns plant counts into seeds, transplants, sets or cloves to buy. Crops started indoors need 4 to 12 weeks under lights before planting out, and the seed starting calculator with indoor sowing dates adds germination temperatures and planting depth for each of them. The planner sits alongside other free garden planning tools and calculators for soil, compost and frost dates.
What Is Square Foot Gardening?
Square foot gardening divides a raised bed into 1 × 1 ft squares and plants each square with 1, 4, 9 or 16 plants depending on crop size. It replaces wide row spacing with even spacing on all sides, so a bed holds several times more plants than rows.
The method grew popular in the 1980s for small gardens, and the plant counts follow simple geometry: 4 plants in a square sit 6 inches apart, 9 plants 4 inches apart and 16 plants 3 inches apart. Crops that spread, such as zucchini and winter squash, take several squares per plant, while vining cucumbers, peas and pole beans fit more per square when they climb a trellis.
| Crop | Plants per square | Spacing inside the square | Row-garden spacing |
|---|---|---|---|
| Tomato (staked or caged) | 1 | centered in the square | 18–36 in |
| Pepper | 1 | centered in the square | 12–18 in |
| Cucumber (trellised) | 2 | 6 in (15 cm) apart in one row | 12–18 in |
| Zucchini / summer squash | 1 per 4–9 squares | one plant in the middle of its block | 24–36 in |
| Potato | 1–4 | centered in the square | 10–12 in |
| Lettuce | 4 | 6 in (15 cm) apart | 8–12 in |
| Carrot | 16 | 3 in (8 cm) apart | 2–3 in |
| Onion (bulb) | 9–16 | 4 in (10 cm) apart | 3–4 in |
| Garlic | 4–9 | 6 in (15 cm) apart | 4–6 in |
| Bush beans | 9 | 4 in (10 cm) apart | 3–6 in |
| Pole beans | 8 | two rows of 4, 3 in (8 cm) apart | 4–6 in |
| Strawberry | 4 | 6 in (15 cm) apart | 12–24 in |
| Basil | 4 | 6 in (15 cm) apart | 10–12 in |
| Kale | 1 | centered in the square | 12–18 in |
| Broccoli | 1 | centered in the square | 12–18 in |
| Cabbage | 1 | centered in the square | 12–24 in |
| Spinach | 9 | 4 in (10 cm) apart | 3–6 in |
| Radish | 16 | 3 in (8 cm) apart | 2–3 in |
| Beet | 9 | 4 in (10 cm) apart | 3–4 in |
| Sweet corn | 1–4 | centered in the square | 8–12 in |
| Peas | 8 | two rows of 4, 3 in (8 cm) apart | 2–3 in |
Typical square-foot-gardening counts; compact varieties fit the higher number of a range. Row spacing is the in-row distance in traditional rows.
Beds laid out in rows or on a diagonal use the same distances. The plant spacing calculator for rows and grids turns spacing in inches into a plant count for any bed or row length.
How Should You Arrange Plants in a Raised Bed?
Put tall and trellised crops such as tomatoes, pole beans, cucumbers and corn along the north edge of the bed in the Northern Hemisphere, medium crops in the middle and low crops along the south edge, so no plant shades another.
The sun sits in the southern half of the sky north of the tropics, so shadows fall to the north. A 5-foot tomato cage shades the square behind it by midsummer; the planner marks those squares with ◐. Shade from a tall crop is useful in hot weather for lettuce, spinach and cilantro, which bolt quickly in full summer sun. In the Southern Hemisphere, reverse the layout and put tall crops on the south edge.
Trellises belong on the north edge too, where they cast no shadow on the bed. Sprawling crops such as winter squash and sweet potatoes do best in a corner, where their vines can trail over the frame into the path. Succession planting keeps squares productive: sow a square of radishes or lettuce every 2 weeks in spring, and replant a square as soon as it is harvested — beans after spring peas, or fall carrots after early onions.
Which Plants Should Not Be Planted Together in a Raised Bed?
The best-supported raised bed conflicts involve shared diseases and pests: tomatoes and potatoes share late blight, spinach and beets share leafminers, and tomatoes and sweet corn share the corn earworm. Fennel and onions next to beans are traditional warnings with weaker evidence.
The planner checks every square against its 8 neighbors, including diagonals, and draws a red ring around squares that touch a conflicting crop. Tap a square to read why, with an evidence level on each pairing: research-supported, practical (space, shade or water) or traditional. Conflicts that spread by disease matter even when the two crops are in opposite corners, so the bed summary lists every conflicting pair in the bed, touching or not.
Good neighbors are marked with a green dot. The strongest pairings are practical: flowering herbs and sweet alyssum that feed hoverflies and parasitic wasps, lettuce in the shade of tomatoes, and pole beans climbing sweet corn. Every crop in the planner links to its companion planting chart with reasons and evidence levels, which also covers plants grown outside raised beds.
What Size and Depth Should a Raised Bed Be?
Build raised beds no wider than 4 ft (1.2 m) so you can reach the middle from either side, or 2 to 3 ft wide against a wall or fence. Most vegetables need 10 to 12 inches (25–30 cm) of soil; carrots, potatoes and tomatoes do best with 12 to 18 inches.
| Bed size | 1-ft squares | Metric | Soil at 12 in deep |
|---|---|---|---|
| 3 × 6 ft | 18 | 0.9 × 1.8 m | 18 ft³ |
| 4 × 4 ft | 16 | 1.2 × 1.2 m | 16 ft³ |
| 4 × 8 ft | 32 | 1.2 × 2.4 m | 32 ft³ |
| 4 × 12 ft | 48 | 1.2 × 3.6 m | 48 ft³ |
| 2 × 8 ft | 16 | 0.6 × 2.4 m | 16 ft³ |
Square count = width × length in feet. In metric mode the planner uses 30 × 30 cm squares.
Length is limited only by the space and the lumber: 8 ft matches standard boards, and beds longer than about 12 ft make you walk around them more often than through them. A 4 × 8 ft bed 12 inches deep takes 32 cubic feet of soil, and the raised bed soil calculator with a topsoil and compost mix converts any bed size into cubic yards and bags.
How Do You Rotate Crops Between Raised Beds?
Rotate by plant family: each year, move each family to a different bed so that no family returns to the same soil for 3 to 4 years. A four-bed rotation typically runs nightshades, then legumes, then brassicas, then root crops and onions.
Soil-borne diseases and overwintering pests usually attack a whole family, not a single crop, so moving tomatoes out of a bed does little if peppers or potatoes replace them. The bed summary in the planner lists the families in each bed; duplicate a bed to plan next year's version of it and swap the families around.
| Plant family | Crops in the planner |
|---|---|
| nightshade family (Solanaceae) | tomatoes, peppers, eggplant, potatoes |
| legume family (Fabaceae) | bush beans, pole beans, peas |
| cabbage family (Brassicaceae) | kale, cabbage, broccoli, cauliflower, brussels sprouts, radishes |
| gourd family (Cucurbitaceae) | cucumbers, zucchini, pumpkins, melons, watermelon |
| onion family (Amaryllidaceae) | onions, garlic, leeks, chives |
| carrot family (Apiaceae) | carrots, celery, dill, cilantro, parsley, fennel |
| amaranth family (Amaranthaceae) | spinach, swiss chard, beets |
Rotate crops of the same family as one group. Legumes such as beans and peas fit well before heavy feeders like brassicas.
How Much Water and Mulch Does a Raised Bed Need?
A raised bed typically needs about 1 inch (2.5 cm) of water a week in cool weather and up to twice that in hot, windy weeks, because raised soil drains and dries faster than the ground. A 2 to 3 inch layer of organic mulch cuts evaporation noticeably.
Water deeply 2 or 3 times a week rather than daily sprinkles, so roots grow down into the full depth of the bed. One inch of water on a 4 × 8 ft bed is about 20 gallons (75 liters). Drip lines or soaker hoses laid along each row of squares keep leaves dry, which slows leaf diseases on tomatoes and squash.
Straw, shredded leaves and fine wood chips work as raised bed mulch once seedlings are a few inches tall; keep it an inch away from stems. The mulch calculator for beds in cubic feet and bags sizes the layer for all your beds at once.
Frequently Asked Questions
- How many plants fit in a 4×8 raised bed?
- A 4 × 8 ft raised bed has 32 one-foot squares. Planted square-foot style it holds anywhere from 32 large plants such as tomatoes or peppers (one per square) to 512 carrots or radishes (16 per square). The mixed kitchen garden template in this planner fits 220 plants of 11 crops.
- What should I plant in my first raised bed?
- Easy first-year crops for a raised bed are lettuce, radishes, bush beans, zucchini, cherry tomatoes, basil and marigolds. They germinate or establish reliably, give a harvest within one season and show quickly how much sun and water the bed gets.
- How far apart should raised beds be?
- Leave paths of 18 to 24 inches (45–60 cm) between raised beds for kneeling and hand tools, and about 36 inches (90 cm) where a wheelbarrow or wheelchair has to pass. Beds wider than 4 ft need access from both sides.
- Can tomatoes and peppers share a raised bed?
- Tomatoes and peppers grow well in the same raised bed because both need full sun, warm soil and steady water. They belong to the nightshade family, so rotate them together: grow a legume, brassica or root crop in that bed the following year.
- Does the raised bed planner save my layout?
- The planner saves every change in your browser automatically, so the layout is still there when you return on the same device. Copy the share link to open the plan elsewhere or send it to someone; print the plan or download each bed as a PNG image.
Frost dates: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals, via the nearest station to each ZIP code. Plants per square, sowing windows and companion relationships: PlantoScan's own compilation of common horticultural practice; seed packets and local conditions take precedence.