Why Rotation Matters
Planting the same crop family in the same soil year after year quietly works against you on three fronts. The first is disease. Many of the worst soil-borne pathogens are family-specific and stubbornly persistent — the organisms behind nightshade wilts and blights can linger in the ground for three to seven years, and brassica club root for far longer. Each season you replant the same family, you feed that reservoir. Rotation starves it: move the family elsewhere and the pathogen left behind has nothing to infect.
The second front is pests. Plenty of insects overwinter in the soil or nearby debris, emerging in spring to find the host they specialize in. Shift that host to another bed and many of them never make the trip. The third is nutrition. Heavy feeders like tomatoes and squash pull enormous amounts of nitrogen; legumes, through their partnership with rhizobia bacteria, put nitrogen back; root crops draw on deeper layers and lighter doses. Rotating these in sequence lets each year's crop partly set the table for the next.
The Four-Year Cycle
The classic scheme sequences families by what they take and give. Year one goes to the heavy feeders — the fruiting nightshades and cucurbits that demand the richest soil, so you plant them when the bed is freshest. Year two brings legumes, which restore the nitrogen the heavy feeders drained. Year three is for root crops and other light feeders that get by on what's left and mine the lower soil rather than the surface. Year four hands the bed to brassicas and leafy greens — moderate feeders whose distinct pest and disease profile gives the bed a clean break before the cycle restarts. Then it begins again.
When You Have Fewer Beds
Most home gardens aren't four tidy beds, and the tool doesn't pretend otherwise. With two beds, alternate two groups year to year — the heavy-feeder-then-legume pairing is the most useful, since it keeps nitrogen cycling. With a single bed, rotate the families through it across the seasons regardless; you lose the year-to-year spatial separation that does the most against disease, but you keep the nutrient balancing and still come out ahead of monocropping. Turning on cover-crop years lets a small garden stretch a short rotation without repeating a family.
What This Tool Can't Do
Treat the plan as a framework, not a verdict. It works at the family level by design, so it won't tell you tomato-then-pepper is risky (it is — they're the same family). It doesn't track the compost or fertilizer you add mid-cycle, doesn't estimate yields, and is no substitute for a soil test every few years. It knows nothing about your microclimate, your past disease pressure, or the weather coming. Start from the schedule it gives you, then adjust based on what your own garden tells you season to season.
Frequently Asked Questions
Why rotate crops?
Rotation does three things at once. It breaks disease cycles — many soil-borne pathogens, like the fungi behind tomato blight or brassica club root, persist for years and build up when you plant the same family in the same spot. It disrupts pests that overwinter in the soil targeting a specific family. And it balances the soil: heavy feeders deplete nitrogen, legumes restore it, and root crops draw on different layers, so rotating evens out the demands instead of mining one bed the same way every year.
How long is a rotation cycle?
Three to four years is the home-garden standard, and this tool plans on a four-year cycle. Four years means a given family only returns to a bed once every fourth season — long enough to starve most family-specific pests and let soil-borne disease decline. If you've had a serious, persistent disease problem, a longer gap helps, but beyond four years the added benefit shrinks while the planning complexity climbs.
What if I only have 1 or 2 beds?
Rotation still helps, just less dramatically. With a single bed, rotate the families through it across the years anyway — single-bed rotation has perhaps half the disease-breaking value of a four-bed scheme, but it's far better than planting the same thing in the same soil annually. With two beds, alternate two groups (heavy feeders and legumes is a classic pairing), or add a cover-crop year to stretch the cycle.
Do herbs rotate too?
Mostly no. Perennial herbs and vegetables — asparagus, rhubarb, rosemary, thyme — stay put for years and aren't part of the rotation; give them a permanent bed. Annual herbs like basil, cilantro, and dill can simply be inter-planted among your rotating crops rather than assigned their own rotation slot. Rotation is really a discipline for annual vegetables grouped by botanical family.
What's the difference between this and the Companion Planting Checker?
They work on different time scales. Crop rotation is about what you plant in a bed across years — making sure this year's tomatoes don't sit where last year's potatoes were. Companion planting is about what you grow next to what within a single season — pairing crops that help each other and separating ones that don't. Both matter, and they're complementary: plan the rotation first, then arrange companions within each bed-year.