What Is Soil Fatigue?

If you grow tomatoes in the same bed three years in a row, you'll notice it: the plants get smaller, more susceptible to disease, and the harvest shrinks. The phenomenon is called soil fatigue and affects hobby gardeners in the DACH region just as much as farmers with hundreds of hectares.

The causes are complex:

Nutrient imbalance: Each plant species draws specific nutrients from the soil
Root exudates: Plants leave behind substances that inhibit the growth of the same species (allelopathy)
Pest cycles: Soil fungi and nematodes specialize in particular plant families
Mycorrhiza depletion: Monocultures weaken the fungal network in the soil

The 4-Field Principle for the Home Garden

Classic crop rotation divides crops into four groups:

1. Heavy Feeders (Year 1)

Plants with high nutrient requirements:

Tomatoes, peppers, squash, zucchini, cabbage, celery
Preparation: Work in compost (3-5 L/m²), and horn shavings if needed

2. Medium Feeders (Year 2)

Moderate nutrient requirements:

Carrots, onions, kohlrabi, fennel, chard, lettuce
Preparation: Light application of compost (1-2 L/m²)

3. Light Feeders (Year 3)

Modest plants:

Beans, peas, radishes, herbs, lamb's lettuce
Bonus: Legumes (beans, peas) fix nitrogen in the soil!

4. Green Manure / Fallow (Year 4)

Regeneration of the soil:

Phacelia, mustard, crimson clover, winter rye
Effect: Loosens the soil, builds humus, suppresses weeds

Practical Example: 4 Beds Over 4 Years

Imagine you have 4 raised beds of 1.2 x 2.4 m – a typical size for allotments in Vienna, community gardens in Hamburg or family gardens in Bern.

	Bed A	Bed B	Bed C	Bed D
2026	🍅 Tomatoes, peppers	🥕 Carrots, onions	🫘 Beans, peas	🌿 Phacelia
2027	🥕 Carrots, chard	🫘 Beans, radishes	🌿 Green manure	🍅 Squash, zucchini
2028	🫘 Peas, herbs	🌿 Mustard, clover	🍅 Cabbage, celery	🥕 Kohlrabi, fennel
2029	🌿 Winter rye	🍅 Tomatoes, peppers	🥕 Lettuce, carrots	🫘 Beans, lamb's lettuce

Mind the Plant Families!

Even more important than heavy/light feeders is family rotation. Plants of the same family should have at least a 3-year break:

Nightshades (Solanaceae): Tomato, pepper, potato, eggplant
Brassicas (Brassicaceae): Cabbage, broccoli, radish, mustard, arugula
Umbellifers (Apiaceae): Carrot, parsnip, celery, parsley, fennel
Legumes (Fabaceae): Bean, pea, lentil, clover

Digital Crop Rotation in PermaNatura

PermaNatura makes crop rotation planning easy:

1. Document Your Beds

Each bed is recorded with its crops in the bed planner. The historical data is retained over the years.

2. Automatic Warning

If you want to plan a tomato where nightshades already grew last year, the companion planting checker warns you automatically.

3. Recommendations

Based on the bed history, PermaNatura suggests suitable follow-on crops – taking into account plant family, nutrient requirements and companion planting compatibility.

4. Harvest Tracking

Document your yields per bed and year. This way you can see across the seasons whether your crop rotation is working or whether yields are declining.

Special Considerations for the DACH Region

Short Growing Season

In the Alpine regions and northern Germany the season is shorter. Make use of:

Starting seedlings on the windowsill from February
Fleece and cold frames for a 2-4 week extension
Winter vegetables: Lamb's lettuce, claytonia, kale survive frost

Soil Types

Northern German sandy soils: More compost, more frequent green manure
Alpine foothills loam soils: Good nutrient buffers, but watch out for waterlogging
Swiss moraine soils: Often calcareous – check the pH value in the soil analysis module

Conclusion: Crop Rotation Is Not Rocket Science

With the 4-field principle and one simple rule – never the same family in the same spot two years in a row – you prevent 80% of all soil fatigue problems. PermaNatura helps you keep the overview, even when after three years you no longer remember where the tomatoes stood in 2026.

Plan your crop rotation digitally. Start PermaNatura for free.

Planning Crop Rotation Digitally: How PermaNatura Prevents Soil Fatigue