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Short answer: Space by area rather than by rows — raised beds have no tractor to drive down them, so the row spacing on a seed packet wastes half your bed. Use roughly 16 carrots, 9 bush beans, 4 lettuces or 1 tomato per square foot. Put tall crops on the north side. And treat most companion planting advice with suspicion: a few pairings have real support, most are folklore repeated until it sounded like fact.
How much a raised bed produces is decided more by spacing and arrangement than by soil, variety or effort. It's also the part people get wrong first, in both directions — crowding twenty plants where eight belong, or following packet spacing designed for a farm field and harvesting a third of what the bed could give.
Why seed packet spacing doesn't apply
Packet instructions come from row agriculture. "Thin to 3 inches, rows 18 inches apart" assumes you need to walk or drive between rows.
In a raised bed you don't. You reach in from the edge, so the paths are outside the bed rather than inside it. That frees the between-row space entirely.
What you keep is the in-row number — the spacing plants actually need from each other to size up. What you discard is the aisle.
The practical effect: intensive spacing in a raised bed typically yields two to four times what row spacing would over the same area, because the plants shade the soil rather than the soil shading between rows. That canopy also suppresses weeds and slows evaporation.
Plants per square foot
The simplest method is to think in square feet and ask how many of a crop fit in one. An 8 × 4 ft bed is 32 squares; a 6 × 3 is 18.
| Per square foot | Crops |
|---|---|
| 16 | Carrots, radishes, onions, scallions |
| 9 | Bush beans, beets, spinach, peas, turnips |
| 4 | Lettuce, Swiss chard, garlic, basil, strawberries, parsley |
| 1 | Tomato, pepper, eggplant, broccoli, cabbage, cauliflower, kale |
| 1 per 2 sq ft | Zucchini, summer squash |
| Trellised | Cucumbers 2 per sq ft, pole beans 8 per sq ft, winter squash 1 per 2 sq ft with support |
Two adjustments worth making:
Give tomatoes more room than one square. An indeterminate tomato in a single square will produce, but air circulation suffers and disease pressure rises. Two squares each is more comfortable if you have the space.
Go slightly wider in hot, humid climates. Dense canopies hold moisture on foliage, and fungal disease is the main constraint in the southeast. Tighter spacing suits dry climates.
Arranging the bed
Tall crops on the north side. In the northern hemisphere the sun tracks across the southern sky, so anything tall on the south side casts shade over everything behind it. Trellised beans, staked tomatoes and corn go at the north end; lettuce, radishes and carrots at the south.
Use the shade deliberately. That shadow north of a tomato row isn't wasted — it's the best place in the bed for lettuce and spinach in midsummer, when they'd otherwise bolt in full sun.
Put quick crops at the edges. Radishes and salad leaves are harvested and replaced several times a season. Keeping them within easy reach of the bed edge saves stretching over established plants.
Group by water need. Thirsty crops like celery and cucumbers next to each other; drought-tolerant herbs like rosemary, thyme and sage in their own zone. Mixing them means one group is always wrong.
Perennials get their own bed. Asparagus, rhubarb, and woody herbs stay put for years. Putting them in a bed you want to dig and replant every season creates a conflict you'll lose.
Companion planting: what holds up and what doesn't
This deserves plain speaking. Companion planting charts circulate widely, get copied between websites, and mostly trace back to a small number of mid-century books rather than to trials. Some pairings have real mechanisms behind them. Many do not.
Here's the honest split.
Well supported
Trap cropping. Planting something pests prefer, to draw them off the crop you care about. Nasturtiums pull aphids away from beans and brassicas; blue hubbard squash draws squash bugs off zucchini. The mechanism is simple and observable.
Attracting beneficial insects. Flowering plants with small, accessible flowers — dill, cilantro allowed to bolt, alyssum, yarrow — feed parasitic wasps and hoverflies whose larvae eat aphids. This is well established and the easiest win available.
Improving pollination. More pollinators near squash, cucumbers and beans means better fruit set. Anything flowering nearby helps.
Physical structure. The Three Sisters — corn as a pole for beans, squash shading the soil below — works because the roles are physical, not chemical.
Living mulch. Low crops like lettuce under taller ones shade soil, reduce evaporation and suppress weeds.
Weakly supported or folklore
Most of the specific "plant X with Y for better flavour" pairings. Basil improving tomato taste is the most repeated example and has no meaningful evidence behind it. Plant basil next to tomatoes because both want the same conditions and you'll use them together — that's a good enough reason without inventing a mechanism.
The same applies to most of the "never plant these together" lists. They're rarely wrong in a way that ruins anything; they're just not doing what the chart claims.
Worth actually avoiding
- Fennel near most vegetables. It genuinely inhibits nearby plants. Give it a container of its own.
- Potatoes and tomatoes in close proximity or in sequence. Same family, shared diseases — blight moves between them readily.
- Anything in the same family in the same spot two years running. This is crop rotation, which matters far more than companion planting does.
- Mint, unless contained. It will take a bed. Grow it in a pot, even a pot sunk into the bed.
If you take one thing from this section: flowers and rotation do most of the work that companion planting charts claim credit for. Add flowering plants to your beds and move crop families around each year, and you've captured the real effect without memorising a grid.
Crop rotation in a small garden
Rotation matters because soil-borne disease and family-specific pests build up where the same crops return year after year.
With only one or two beds, a strict four-year rotation isn't practical. A simplified version still helps: group by family and move each group to a different part of the bed, or a different bed, each year.
| Family | Crops | Note |
|---|---|---|
| Nightshades | Tomato, pepper, eggplant, potato | The most important group to move |
| Brassicas | Cabbage, broccoli, kale, radish, turnip | Clubroot persists in soil for years |
| Legumes | Beans, peas | Fix nitrogen — good to follow heavy feeders |
| Alliums | Onion, garlic, leek, scallion | Few shared problems, flexible |
| Cucurbits | Cucumber, squash, melon | Heavy feeders |
| Roots | Carrot, beet, parsnip | Light feeders — good after legumes |
A workable sequence for one bed: legumes → leafy or brassicas → nightshades or cucurbits → roots, then back to legumes.
Succession planting: the yield multiplier
Most beds sit half empty for part of the season. Succession planting fixes that, and it's the single biggest increase in output available from a bed you already have.
Replace as you harvest. When spring radishes come out in May, something goes in that square the same week.
Stagger fast crops. Sow a short row of lettuce every two weeks rather than the whole packet at once. You get a continuous supply instead of forty heads maturing together.
Plant a late-summer round. Lettuce, spinach, radishes and Asian greens sown in late summer mature in cooling weather and are among the easiest crops of the year. Most gardens stop in August, which is when they should be sowing again.
Interplant fast among slow. Radishes between tomato transplants are harvested long before the tomatoes need the room.
A worked plan: one 8 × 4 ft bed
Thirty-two square feet, for a household of two, at 24 inches deep.
| Zone | Squares | Planting |
|---|---|---|
| North end, trellised | 4 | Pole beans or cucumbers, 8 per square on a trellis |
| North, second row | 4 | 2 tomatoes at 2 squares each, staked |
| Middle | 4 | 2 peppers, 1 zucchini across 2 squares |
| Middle | 6 | Bush beans at 9 per square |
| South, near edge | 6 | Lettuce at 4 per square, replaced as harvested |
| South, near edge | 4 | Carrots and radishes at 16 per square |
| Corners and gaps | 4 | Basil, parsley, and flowering herbs left to bloom |
Those flowering herbs in the last row aren't decoration. Dill and cilantro allowed to flower bring in the parasitic wasps and hoverflies that handle aphids for you, which is the most reliable pest control on this page.
Frequently asked questions
How many plants can I fit in a raised bed?
Space by area rather than rows. Roughly 16 carrots or radishes, 9 bush beans or beets, 4 lettuces, or 1 tomato or pepper per square foot. An 8 by 4 ft bed is 32 squares.
Should I follow the spacing on the seed packet?
Only the in-row number. Packet spacing assumes rows you walk between, which a raised bed doesn't have because you reach in from the edge. Discarding the aisle typically doubles or triples what the same area produces.
Where should tall plants go in a raised bed?
On the north side, so they don't shade shorter crops. The shadow they cast is useful in summer — it's the best spot in the bed for lettuce and spinach, which bolt in full sun.
Does companion planting actually work?
Some of it. Trap cropping, attracting beneficial insects with flowering plants, improving pollination, and physical arrangements like the Three Sisters have real mechanisms. Most specific "plant X with Y for better flavour" pairings are folklore. Flowers and crop rotation deliver most of the benefit those charts claim.
What should you not plant together?
Fennel genuinely inhibits many nearby plants and is best grown separately. Keep potatoes and tomatoes apart, since they share diseases. Contain mint in a pot. Beyond that, avoiding the same plant family in the same spot two years running matters far more than any pairing rule.
What is succession planting?
Replanting a space as soon as a crop finishes, and staggering sowings of fast crops so they mature in sequence rather than all at once. It's the largest yield increase available from a bed you already have.
Do I need to rotate crops in a raised bed?
Yes, though a simplified version is fine in a small garden. Group crops by family and move each group to a different area each year. Nightshades — tomatoes, peppers, eggplant, potatoes — are the most important to move.
Still setting up? See our guides to starting your first raised bed, garden layout and spacing, and choosing a bed height.