Crop Rotation Garden Planner: 4 Beds, 4 Years

Step 1: Sort your crops by plant family

Plant family is the only fact you need to start. Washington State University says vegetables in the same family are often hit by the same insect pests and diseases, and they take up similar nutrients. Plant the same family in the same spot year after year and pests get a reliable food source.

A Washington State University Extension fact sheet from Snohomish County gives a table of common vegetables and their families. The rows below are taken from it.

Write your own crop list next to the family names. Radish surprises people, because it belongs with the cabbage family. Peppers and potatoes surprise people the other way, because they share a bed group with tomatoes.

Crops in the same family share pests, so a new bed beats a new variety.

Step 2: Give each family group its own bed

Four beds fit four family groups. Washington State University's four-bed, four-year diagram uses potatoes (nightshade), kale (broccoli family), peas (pea and bean family) and beets (goosefoot family).

Clemson Cooperative Extension builds its sample the same way with four beds and four crops: tomatoes, sweet corn, okra and beans. A 2021 Clemson fact sheet also says rotating tomatoes, peppers and eggplant with each other is not recommended, because all three are nightshades.

Squash, onions and carrots sit outside those four groups. Give each one a bed of its own if you have the room, or add a fifth bed. Write the family beside every crop so you always know which group a bed belongs to.

Step 3: Fill the crop rotation garden planner grid

Shift every group one bed to the right each spring. The group in bed 4 wraps around to bed 1. Clemson's table moves each crop one bed per year too.

The grid has 16 cells, which is 4 beds times 4 years. Each family appears 4 times, and each bed holds every family once. Nightshade sits in bed 1 in year 1 and does not return until year 5. That is a four-year gap, the top of Washington State University's advice to wait three to four years. Clemson calls three years the minimum and says four or five is even better.

Step 4: Write each year's bed map down

The grid only works if you can see where things grew. The Snohomish County fact sheet says to keep a garden log or map as a reminder of where vegetables are planted each year. A pencil sketch of four boxes with the crops named inside is enough.

Print a fresh copy each spring. Cross out last year's family, write the new one, and note any crop that did badly. If a bed picked up a disease, that note tells you to keep its family away longer than four years.

Cross out last year's family on a ruled sheet and the new grid is done.

What to plant after tomatoes

Tomatoes belong to the nightshade family, so the next crop in that bed must come from another family. Peppers, eggplant and potatoes are the crops to avoid after tomatoes, and the Washington State fact sheet says why: all of them are nightshades. Clemson's sample table follows tomatoes with sweet corn.

In the grid above, the bed that held nightshades gets the goosefoot group the next year. Beets, spinach and Swiss chard all come from that family. After that, the pea and bean group takes the bed, and then the broccoli family.

If the Same Family Is Already in Last Year's Bed

You planted tomatoes where tomatoes grew last year, and you cannot move them. Do not plant that family there a third time. The Washington State fact sheet says even changing the plant family in an area from year to year helps manage pests and diseases. Next spring, put a different family in that bed, such as beets or beans, and write the swap on your map.

The University of Georgia Extension disease guide gives three steps for the current season. It says to remove the plants and plant residue after harvest and uproot entire plants when possible. It says planting resistant varieties is the most efficient way to manage troublesome vegetable diseases. It also says soilborne problems may need longer rotations or other management. If a bed picked up disease, keep that family out for longer than four years.

Small plots where a four-bed rotation does not fit

You may only have one raised bed. A four-bed, four-year grid does not fit one bed. A three to four year gap can be hard to reach in small gardens, the Washington State fact sheet says, but even changing the plant family in an area from year to year helps manage pests and diseases. Swap families each spring and keep the map.

A free county or land-grant fact sheet does the same sorting as the table in Step 1, so use it if it fits your crops. The grid cannot give you dates, though. The Winter Plan counts sowing and transplant weeks from the last-frost date you write in, and a 108-station NOAA freeze table in the file means any US zone works. It arrives as a zip of US Letter and A4 PDFs through a download link sent by email, and you print it at 100 percent so bed plans keep true scale. Fill in the rotation planner in winter, then use the Winter Plan's notes for next winter at season's end, so the new grid starts from what happened.