A family-based rotation puts one botanical family in each bed and moves every family one bed along each year, so a cycle of n beds returns each family to the same bed every n years and gives n − 1 years away. Decide the number of beds from the longest break the worst disease of any family in the cycle requires, then check that the order also passes nitrogen from legumes to the hungriest crops.
A family-based rotation schedule assigns crops to beds by botanical family and cycles the families so that no family follows itself.
Why The Carrier’s Four Groups Need Refining
The carrier’s four-year cycle uses four groups: legumes, brassicas, solanaceae, and “roots and alliums”. The last group is a convenience, not a family: carrot and parsnip are Apiaceae, onion and garlic are Amaryllidaceae, and beet and spinach are Amaranthaceae. A bed of “roots and alliums” holds three families that come back together, so each is on a four-year return, which is adequate for some pests and short for others. The cycle also leaves out cucurbits, maize and lettuce.
The Families, Verified By Botany
| Family | Crops | Notes |
|---|---|---|
| Fabaceae (legumes) | Bean, pea, lentil, clover | Fix nitrogen |
| Brassicaceae | Cabbage, kale, broccoli, turnip, radish, mustard | Clubroot; radish and mustard count |
| Solanaceae | Potato, tomato, pepper, aubergine | Late blight, wilts, nematodes |
| Cucurbitaceae | Squash, cucumber, melon | Share beetles, mildews |
| Apiaceae | Carrot, parsnip, celery, parsley, dill, fennel, coriander | Carrot fly |
| Amaryllidaceae | Onion, garlic, leek | Onion maggot, white rot |
| Amaranthaceae | Beet, chard, spinach | |
| Poaceae | Maize, wheat, oats, barley | Grains |
| Asteraceae | Lettuce, sunflower |
The Phase 2 families guide (Crop Families) works at this level.
How To Build A Schedule
Step 1: List the families you actually grow and the area of each.
Step 2: Find the longest break the worst problem needs. Intervals from the Phase 2 pest guide (Pest Disruption): corn rootworm 1-2 years, Colorado potato beetle 2-3, onion maggot 3-4, potato cyst nematode 5-6 or more. With n beds, the family is away n − 1 years, so n = break + 1. For onion maggot at 3-4 years away, use 4-5 beds; for nematodes, 6-7 beds or keep that family on its own land.
Step 3: Order the families so that heavy feeders follow legumes and light feeders come last (Nutrient Cycling Through Rotation).
Step 4: Shift the whole sequence one bed each year.
Step 5: Equal areas. Each bed should be roughly the same size, because each family takes a turn in every bed.
Worked Example: Six Beds, Six Families
Sequence: legumes, brassicas, solanaceae, cucurbits, Apiaceae (carrot family), alliums. Bed A starts at the first; each later bed starts one step further along.
| Bed | Year 1 | Year 2 | Year 3 | Year 4 | Year 5 | Year 6 |
|---|---|---|---|---|---|---|
| A | Legumes | Brassicas | Solanaceae | Cucurbits | Apiaceae | Alliums |
| B | Brassicas | Solanaceae | Cucurbits | Apiaceae | Alliums | Legumes |
| C | Solanaceae | Cucurbits | Apiaceae | Alliums | Legumes | Brassicas |
| D | Cucurbits | Apiaceae | Alliums | Legumes | Brassicas | Solanaceae |
| E | Apiaceae | Alliums | Legumes | Brassicas | Solanaceae | Cucurbits |
| F | Alliums | Legumes | Brassicas | Solanaceae | Cucurbits | Apiaceae |
Check: every column holds each family exactly once (each family occupies one bed per year), and every row holds each family exactly once (every bed has a different family each year). Each family returns to its bed after 6 years, five years away. Beet, spinach and maize are not in this cycle; add a seventh bed or fit beet with the allium group if no problem is known.
Check the transitions. Brassicas follow legumes, which suits them. After that the order runs solanaceae, cucurbits, Apiaceae and alliums, and legumes close the loop. The weakness is that three nutrient-hungry families (brassicas, solanaceae and cucurbits) come in a row after one legume year, so compost or manure must be added to those beds. The families in adjacent steps share few diseases, but check any pair you add against the pest tables.
Failure Modes
- Different bed sizes. A family that has a small bed one year and a large bed the next breaks the food plan.
- Unplanned crops. Volunteer potatoes or self-sown brassicas count as a crop of that family and break the break; remove them.
- A pathogen with a wild host. Weeds in the same family (shepherd’s purse in brassicas) keep the pathogen alive in the “empty” years.
- Skipped records. The plan lives in the notebook, not in memory.
- Perennials. Asparagus and fruit bushes sit outside the cycle.
What’s Next
- Learn next: Soil-Borne Disease Prevention — when rotation alone does not suffice
- Combine with: Rotation Planning — the Phase 2 master plan