Formula and Planning Logic
The calculator converts every selected area into square metres. It scores each crop against family gaps, feeding demand, season, soil, disease, and planning mode. Higher scores indicate safer and more balanced planting choices.
Suitability score = base score + seasonal fit + rotation benefits + mode bonuses − repetition penalties − disease penalties Estimated plants = bed area ÷ (plant spacing × plant spacing) Estimated yield = crop yield rate × bed area × yield factor Estimated profit = estimated revenue − seed, compost, fertiliser, labour, and other costs
How to Use
Enter the total growing area and number of beds. Select seasons, preferred crops, rotation rules, and known field problems. Submit the form to create an editable planning reference.
Add previous crops whenever reliable records are available. Choose pest-control mode when disease pressure matters most. Review every warning before confirming the final planting schedule.
Crop Family Reference
| Family | Common crops | Rotation concern | Typical interval |
|---|---|---|---|
| Solanaceae | Tomato, potato, pepper | Blight and wilt carryover | 3–4 years |
| Brassicaceae | Cabbage, broccoli, cauliflower | Clubroot and root fly | 4–6 years |
| Fabaceae | Bean, pea, clover | Root diseases and nitrogen balance | 3 years |
| Cucurbitaceae | Cucumber, pumpkin, melon | Mildew and soil-borne disease | 3 years |
| Apiaceae | Carrot, parsnip | Root pests and nematodes | 3 years |
| Amaryllidaceae | Onion, garlic | White rot persistence | 4–8 years |
Example Rotation Plan
| Year | Bed | Crop group | Purpose |
|---|---|---|---|
| 1 | Bed 1 | Legumes | Add nitrogen before demanding crops |
| 2 | Bed 1 | Brassicas | Use nitrogen added previously |
| 3 | Bed 1 | Roots and alliums | Use moderate fertility without fresh manure |
| 4 | Bed 1 | Fruit crops | Apply compost and support structures |
Important Limitations
Crop performance varies with weather, varieties, water, and management. Disease persistence may require longer intervals than general recommendations. Confirm serious disease decisions with qualified local agronomy support.
Frequently Asked Questions
What is crop rotation?
Crop rotation changes plant families across beds over time. It can reduce pest carryover and balance nutrient demand. Good records make every future rotation decision more reliable.
How long should a rotation last?
Many gardens use three-year or four-year rotation plans. Serious soil diseases can require longer exclusion periods. Select intervals matching your crops and recorded field problems.
Why rotate crop families?
Related crops often share diseases and insect pests. Repeating families can increase pressure within the same soil. Longer family gaps usually lower avoidable biological risks significantly.
Should legumes come before heavy feeders?
Legumes can contribute nitrogen through biological fixation processes. Their residues may support following nutrient-demanding crops. Actual nitrogen benefits depend on inoculation, growth, and incorporation.
Can I use cover crops?
Cover crops protect soil between commercial or garden crops. They may add nitrogen, suppress weeds, or improve structure. Match each cover species with season and management goals.
What happens when disease is selected?
The calculator penalises crops associated with that selected disease. Higher penalties lower suitability scores and increase warnings. Use local guidance for confirmed long-lived soil pathogens carefully.
Are yield estimates guaranteed?
No calculator can guarantee actual harvest or market returns. Estimates use average spacing, yield, and price assumptions. Replace defaults with realistic values from your own records.
Can beds have different names?
Yes, enter one custom bed name per line. The calculator creates missing names when necessary. Exact names also support history and manual crop assignments.
What does the suitability score mean?
The score combines rotation benefits and detected conflicts. Higher scores indicate stronger matches under selected rules. Review notes because one score cannot replace field judgement.
How can I download the plan?
Use CSV for spreadsheets and further record keeping. Use PDF for a printable rotation schedule. The copy button creates a quick plain-text planning summary.