A crop rotation chart groups vegetables by plant family and moves each group to a different bed every year, so that no family grows in the same soil again for three or four years. The point is not the individual crop but the family: tomatoes, peppers, eggplant and potatoes share the same diseases and pests, so they count as one crop for rotation, and a bed that grew potatoes last year is a bad place for tomatoes this year.
The chart below covers the 24 crops on this site. It sorts them into 10 families, says how long each family should stay out of a bed and why, and then turns that into a four-bed and a three-bed plan you can copy.
Crop families and how long to keep them out of a bed
| Family | Crops | Years out | What builds up if you skip it |
|---|---|---|---|
| Nightshade (Solanaceae) | tomatoes, peppers, eggplant, potatoes | 3 to 4 | Early blight, Septoria leaf spot, Verticillium wilt, Colorado potato beetle |
| Squash (Cucurbitaceae) | cucumbers, zucchini, winter squash, pumpkins | 2 to 3 | Squash vine borer, Fusarium wilt, anthracnose |
| Cabbage (Brassicaceae) | broccoli, kale, radishes | 3 to 4 | Clubroot (spores last up to 20 years), cabbage root maggot, black rot |
| Pea and bean (Fabaceae) | beans, peas | 2 to 3 | Fusarium and Pythium root rots, Aphanomyces in peas |
| Onion (Amaryllidaceae) | onions, garlic | 3 to 4 | Onion maggot, stem nematode, white rot (15 years or more) |
| Carrot (Apiaceae) | carrots, parsley, cilantro | 2 to 3 | Carrot rust fly, root-knot nematodes |
| Beet (Amaranthaceae) | beets, spinach | 2 to 3 | Cercospora leaf spot, leaf miners |
| Daisy (Asteraceae) | lettuce, sunflowers | 2 | Lettuce drop (Sclerotinia) |
| Grass (Poaceae) | corn | 1 to 2 | Corn rootworm |
| Mint (Lamiaceae) | basil | 2 to 3 | Fusarium wilt of basil |
The year counts are the ranges extension services give for home gardens, and the longer end is for a bed where you have actually seen the problem. Two entries are outside what rotation can fix: once clubroot or onion white rot is established, the bed is effectively lost to that family for a decade or more, so the real defense is never bringing them in on infected transplants or sets.
Three family memberships catch people out. Radishes are brassicas, so they belong with broccoli and kale, not with carrots. Potatoes are nightshades, so they count against tomatoes. Spinach is in the beet family, so it travels with beets rather than with lettuce.
The four-bed rotation chart
The classic plan sorts the families into four groups and moves each group one bed along every year. The order is not arbitrary: each group sets up the soil for the next.
| Group | Crops | Why it goes here |
|---|---|---|
| 1. Legumes | beans, peas | Fix their own nitrogen and leave some in the soil |
| 2. Leaves and brassicas | broccoli, kale, radishes, lettuce | Want the most nitrogen, so they follow the legumes |
| 3. Fruiting and summer crops | tomatoes, peppers, eggplant, potatoes, cucumbers, zucchini, squash, pumpkins, corn, basil, sunflowers | Heavy feeders; this is the bed that gets the compost |
| 4. Roots and alliums | carrots, parsley, cilantro, beets, spinach, onions, garlic | Do best in soil with no fresh manure, which makes carrots fork and onions soft |
| Year | Bed A | Bed B | Bed C | Bed D |
|---|---|---|---|---|
| 1 | Legumes | Leaves and brassicas | Fruiting crops | Roots and alliums |
| 2 | Roots and alliums | Legumes | Leaves and brassicas | Fruiting crops |
| 3 | Fruiting crops | Roots and alliums | Legumes | Leaves and brassicas |
| 4 | Leaves and brassicas | Fruiting crops | Roots and alliums | Legumes |
Every group returns to its starting bed in year 5, so each family is out for three years, which meets at least the low end of the range for every family in the table. Sunflowers are in the daisy family with lettuce but go in the summer bed because they grow and feed like corn. Basil goes with tomatoes because that is where it is planted anyway, and nothing else in group 3 is a mint.
The obvious problem is that group 3 is far bigger than the others. Most gardens deal with that in one of two ways: give the summer crops two beds and run a five-bed rotation (nightshades in one, squash and corn in the other), or keep potatoes out of the garden beds entirely and grow them in bags with fresh mix each year.
The three-bed version
With three beds, combine the legumes and the leaves, because the legumes feed the brassicas in the same bed over the course of a season (peas in spring, then kale or broccoli in late summer).
| Year | Bed A | Bed B | Bed C |
|---|---|---|---|
| 1 | Legumes, leaves and brassicas | Fruiting crops | Roots and alliums |
| 2 | Roots and alliums | Legumes, leaves and brassicas | Fruiting crops |
| 3 | Fruiting crops | Roots and alliums | Legumes, leaves and brassicas |
Each family is out of a bed for two years. That is the minimum for nightshades and brassicas, so if blight or root maggot is already a problem, move to four beds or take the troubled family out of the rotation into containers.
Rotation where you grow two crops a year
In zone 8 and warmer, and in zones 6 and 7 with a little planning, many beds grow two crops in one calendar year. Rotation then counts crops, not years: what matters is which family was in the bed last, not what the calendar says.
Two common sequences show how it works. In zone 6a, garlic planted in October comes out in early July, and bush beans can follow it if they are sown by about July 22. That is an allium followed by a legume, which is a correct step in the rotation. In zone 9a, tomatoes transplanted around March 15 are finished by July or August, and fall broccoli sown by about October 3 can follow them for a harvest in early December. That is a nightshade followed by a brassica, also fine.
What you must not do is follow a family with itself: spring tomatoes with fall tomatoes, which is a real temptation in zones 9b and 10 where a second tomato crop is normal, or spring radishes with fall broccoli. The fall planting calendar gives the sow-by dates for your zone, and the companion planting chart covers what can share a bed at the same time, which is a different question from what should follow what.
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What crop rotation does not fix
Rotation works against problems that live in the soil and wait for the same crop to come back. It does very little against diseases that arrive on the wind. Late blight of tomatoes and potatoes, powdery mildew on squash and downy mildew on basil travel miles as airborne spores, and moving the crop ten feet does not change anything. For those, resistant varieties, spacing for airflow and removing infected plants are the levers.
It also works less well the smaller the garden. If your beds are three feet apart, soil and spores move between them on boots, tools and splashing water, so rotation becomes one layer of protection rather than the whole answer. It still pays off against insects whose young wait in the bed: corn rootworm larvae that hatch in spring and starve without corn roots, squash vine borers that pupate under last year’s plants, and carrot rust fly maggots.
And it does not replace cleanup. A bed of diseased tomato vines left to rot in place over winter puts the spores straight back into the soil you just rotated away from. Bag diseased plants for the trash rather than composting them in a home heap, which rarely gets hot enough to kill the spores.
Containers and cover crops
Containers are the easiest place to rotate, because you can simply replace the soil. Potting mix that grew tomatoes or peppers should go on a bed with a different family, not back into a tomato pot. Fresh mix each year in the pots for your most trouble-prone family is the cheapest disease control there is.
A bed that would otherwise sit empty over winter can take a cover crop, and the cover crop counts in the rotation. Crimson clover and hairy vetch are legumes, so they can stand in for the legume year or be added ahead of the brassica bed. Cereal rye is a grass, unrelated to any vegetable here except corn, and it is the one cover crop that still germinates in the cold soil of late October and November, as covered in the October planting guide.
Keep a map
None of this works without a record of what grew where. A rough sketch of your beds with the crops written in, one per year, is enough; a photo of it on your phone is better than nothing. The best time to draw next year’s plan is December, when the season is fresh in your mind and the seed catalogs are arriving, which is the planning half of what to plant in December. Once you know which bed each group is going to, look up the sowing dates for your zone on your zone page and the seed-starting guide.