Companion Planting Layout Planner: Design Your Garden Bed

You have a 4 by 8 foot raised bed, a stack of seed packets, and a hand-drawn rectangle on graph paper. The question is which crop goes where. Get this wrong and your tomatoes shade your lettuce by July, your fennel suppresses everything within ten feet of it, and the cabbage you planted in the same square as last year gets clubroot for its trouble. Get it right and you produce 28 percent more food per square foot than the same crops in monoculture rows, with fewer pests and less work. match your layout to the right season

This is the working layout playbook for a home companion planting garden. You will get the six layout templates that have stood up to extension-service review, the spacing math behind square foot gardening, the orientation rule that protects shorter crops from being shaded out, and the family-rotation table that prevents soil-borne disease pulses. If you have come from our pillar on companion planting, this is how you turn that chart into a bed plan.

The Seven Rules Behind Every Good Layout

Every working companion planting layout follows seven structural rules. Skip any of them and the rest of the design starts to wobble. None of them is exotic.

1. Keep beds no more than 4 feet wide. University of Minnesota Extension sets this as the working maximum so you can reach the centre from either side without stepping on the soil. Soil compaction from foot traffic is the single fastest way to destroy a productive bed.

2. Run the long axis east-west and put your tallest plants on the north edge. Tall crops on the north side never shade the rest of the bed as the sun moves east to west. Reverse this and your trellised cucumbers will shade your lettuce for half the day.

3. Get 6 to 8 hours of direct sun. Full-sun crops (tomato, pepper, eggplant, squash, corn) need at least 6 hours, ideally 8 (UMN Extension). Below 6 hours, restrict the bed to leafy greens, brassicas, and herbs.

4. Plant in blocks, never single long rows. Block plantings expose more leaf surface to the sun than the same plants in a row, improve pollination for wind-pollinated crops like corn, and let companion species occupy adjacent micro-niches.

5. Use square foot densities, not row spacing. Row spacing on seed packets was written for tractors. In a raised bed, what matters is the plant-to-plant spacing, applied to a 1 square foot grid.

6. Rotate by plant family on a 3-year cycle. Both Penn State Extension and Cornell Cooperative Extension recommend a minimum three-year rotation between any two members of the same family in the same bed.

7. Build in flowers and trap crops. Not for decoration. Calendula, borage, alyssum, nasturtium, and marigold pull in pollinators, attract pest predators, and (in the case of marigolds) suppress soil nematodes.

Square Foot Gardening: The Density Framework

Square foot gardening (SFG) is the easiest density framework to plug companion planting into. Mel Bartholomew, a retired engineer, formalised it in 1976 and codified it in his 1981 Rodale book. The premise: divide a 4x4 ft bed into sixteen 1 sq ft sections, and plant each square with 1, 4, 9, or 16 plants depending on mature size (Square Foot Gardening Foundation history). The numbers come from a simple formula: plants per square = (12 / spacing in inches)².

Sources: Square Foot Gardening Foundation method, SFG Foundation 2024 spacing reference.

Vine crops break the grid. Pole beans and indeterminate tomatoes need a trellis and occupy 1 square plus vertical airspace. Vining squash and pumpkins take 4 to 9 squares and are usually staked outside the SFG bed or trained over a path.

Bed Orientation: The Rule That Stops Self-Shading

Run the long axis of the bed east to west, and put the tallest plants on the north edge. UMN Extension and most home-garden extension publications converge on the same rule: north-side trellising for vertical climbers, mid-bed for medium-height crops like tomatoes and peppers, south edge for low crops like lettuce, radish, and onion. The sun moves east to west across the southern sky in the Northern Hemisphere, so a north-edge trellis casts its shadow off the bed to the north, not over the rest of your plants.

Three growing zones emerge naturally from this orientation:

The Family Rotation Rule

The single mistake that kills a productive raised bed faster than anything else is replanting the same family in the same square next year. Soil-borne diseases (clubroot in brassicas, early blight in nightshades, Fusarium wilt in cucurbits) build up in the soil where their host has been growing. A 3-year minimum rotation breaks the cycle.

Sources: Penn State Extension, Cornell Cooperative Extension.

The easiest way to track rotation is to assign each bed a number, draw the plan on paper at the start of each season, and keep the prior two years' plans in the same folder. Heavy feeders (nightshades, brassicas, cucurbits) should rotate to a bed where a legume grew the previous year, since legumes fix nitrogen and leave behind soil ready for a heavy feeder.

Six Layout Templates That Work

Pick the template that matches your space and ambitions. None of these is a folk recipe; each has documented practitioner use and, in the case of the Three Sisters, peer-reviewed yield data.

Sources: Cornell Gardening, Iowa State Three Sisters Intercropping, Backwoods Home keyhole garden.

Most home gardeners do best starting with the Square Foot Garden template for one 4x4 or 4x8 bed and adding a Three Sisters mound or two on an adjacent patch of bare ground or in a second bed. The mandala and spiral are higher-effort builds, worth doing once you know what you grow well.

The Flowers and Trap Crops You Actually Want

The case for integrating flowers into a vegetable bed is no longer folk wisdom. A peer-reviewed field trial published in Ecological Entomology found that strawberries grown next to pollinator-attracting companion plants (alyssum, borage, calendula, phacelia) produced significantly higher yields and better-formed fruit than control plots, driven by improved pollinator visits (Hellström et al., 2020). The same logic applies to any pollination-dependent crop in your bed: squash, cucumber, melon, tomato, pepper.

French marigolds (Tagetes patula) are the textbook example of a soil-acting companion. LSU AgCenter documents that French marigold root exudate (alpha-terthienyl) suppresses several genera of plant-parasitic nematodes, with the strongest effect when marigolds are grown as a full-season cover crop the year before a nematode-susceptible crop like tomato.

Nasturtium acts as a trap crop, drawing squash bugs and aphids away from your cucurbits and brassicas (Connecticut Public). Plant a fringe at the upwind edge of the bed and accept that the nasturtium will get chewed up. That is the job.

Basil earns its place next to tomato through a documented chemical mechanism. Peer-reviewed work in PMC showed that companion basil primes tomato plants to upregulate wound-response genes before the tomato is actually attacked, lowering pest damage when herbivory begins.

What Not To Plant Together

Sources: Penn State Extension, Plantura on fennel, UMN Extension companion planting.

Putting It Together: A 4 by 8 Foot Companion Bed

Here is a concrete example for a 4 by 8 ft bed oriented east-west, running 32 square feet total. Following the seven rules from the top of this article:

North edge (squares 1 to 8, 4 to 6 ft trellis): 4 squares of pole beans (1 plant per square at the trellis base) and 4 squares of indeterminate tomato (1 plant per square, staked).

Middle row (squares 9 to 16): 2 squares basil (4 plants per square, planted near tomato), 2 squares parsley (4 plants per square), 2 squares pepper (1 plant per square), 2 squares bush bean (4 plants per square).

Middle row two (squares 17 to 24): 2 squares lettuce (4 plants per square), 2 squares spinach (9 plants per square), 2 squares Swiss chard (4 plants per square), 2 squares beetroot (9 plants per square).

South edge (squares 25 to 32): 4 squares carrots (16 plants per square), 2 squares radish (16 plants per square), 2 squares onion sets (16 plants per square).

Corners and perimeter: French marigold and calendula at the four corners, nasturtium trailing the south edge, alyssum tucked into the gaps. None of these counts against your square allocations; they share the soil with the edge crops.

That layout combines 11 vegetable species, 5 companion herbs, and 4 pollinator/trap flower species on 32 square feet a brassica-specific companion plan. With a 3-year rotation, the same bed becomes a brassica + Apiaceae + allium + green-manure bed in year two, and a cucurbit + legume bed in year three.

Frequently Asked Questions

What is the best companion planting layout for a 4x8 raised bed?

Orient the bed east-west. Put tall trellised crops (pole beans, indeterminate tomato) on the north edge. Place medium-height crops (pepper, eggplant, bush bean, Swiss chard) in the middle. Place low quick crops (lettuce, radish, carrot, onion) on the south edge. Tuck French marigold, calendula, and nasturtium into the corners. Plant 1, 4, 9, or 16 plants per square foot depending on mature plant size.

How do you plan a companion planting garden from scratch?

Five steps. First, map sun exposure and pick a spot with 6 to 8 hours of direct sun. Second, build raised beds no more than 4 feet wide. Third, lay out a 1 square foot grid on each bed. Fourth, fill each square using Mel Bartholomew's density formula (12 divided by the plant's spacing in inches, then squared). Fifth, rotate plant families on a 3-year cycle to break disease cycles. Add flowers (calendula, alyssum, marigold) and trap crops (nasturtium) along the perimeter.

How many plants can you grow in one square foot?

One large plant (tomato, pepper, broccoli, kale), 4 medium plants (lettuce, basil, parsley, bush bean), 9 small plants (spinach, beet, turnip), or 16 very small plants (carrot, radish, chive, onion set). The formula is plants per square = (12 divided by spacing in inches) squared. So 6 inch spacing = 4 plants per square, 4 inch spacing = 9 plants per square, 3 inch spacing = 16 plants per square.

Which way should a raised garden bed face?

The long axis should run east to west, with the tallest crops on the north edge. This way the sun moves across the southern sky east to west without your trellised vine crops shading the shorter plants beside them. UMN Extension and most home-garden extension publications agree on this orientation.

What is the difference between companion planting and crop rotation?

Companion planting is what you grow next to each other in the same bed and season (tomato next to basil, marigold around the perimeter). Crop rotation is what you grow in the same bed across successive years. Both matter. You can have perfect companions and still get clubroot if you replant brassicas in the same square three seasons running.

Do flowers really increase vegetable yields?

Yes, and there is peer-reviewed data on it. A 2020 study in Ecological Entomology found that strawberries grown with pollinator-attracting companion flowers (alyssum, borage, calendula, phacelia) produced higher yields and better-formed fruit than control plots, driven by improved pollinator visits. French marigolds also suppress plant-parasitic nematodes in the soil, an effect documented by LSU AgCenter.

What plants should never be planted together?

Tomato + fennel (fennel allelopathy). Pole beans + alliums (alliums suppress rhizobia in bean roots). Brassicas + strawberry (pest overlap). Any vegetable within 50 to 80 ft of a black walnut tree (juglone phytotoxicity, documented by Iowa State Extension). Avoid replanting the same plant family in the same bed within 3 years.

Resources

• Square Foot Gardening Foundation, History of the Method
• Square Foot Gardening Foundation, The Method
• Square Foot Gardening Foundation, Square Foot Spacing (2024)
• University of Minnesota Extension, Raised Bed Gardens
• UMN Extension, Companion Planting in Home Gardens
• Penn State Extension, Plant Rotation in the Garden Based on Plant Families
• Cornell Cooperative Extension, Rotating Vegetables by Family
• Cornell Cooperative Extension, How to Build a Raised Garden Bed
• Cornell Gardening, How to Plant the Three Sisters
• Iowa State University Extension, Three Sisters Intercropping
• Iowa State Extension, Plants Sensitive to Juglone from Black Walnut
• LSU AgCenter, Marigolds May Help Control Some Nematodes
• Montana State University Extension, The Science of Companion Planting in the Garden
• Oregon State University Extension, Manage Garden Pests with Smart, Safe Strategies
• Li et al., PMC9926256, The Productive Performance of Intercropping (peer-reviewed)
• Companion Basil Plants Prime the Tomato Wound Response, PMC11263239 (peer-reviewed)
• Hellström et al., Ecological Entomology 2020, Pollinator Companion Plants and Strawberry Yield (peer-reviewed)
• Cambridge Experimental Results, Robustness of Land Equivalent Ratio (peer-reviewed)
• PMC10331949, Influence of Companion Planting on Microbial Compositions (peer-reviewed)
• Plantura Garden, Planting Fennel Companion Plants
• Connecticut Public, Reduce Squash Bugs Naturally
• Backwoods Home, Build a Keyhole Garden
• UC ANR, Companion Planting in the Vegetable Garden (PDF)
• ATTRA/NCAT, Companion Planting and Botanical Pesticides (PDF)