Crop rotation

Why rotate your crops?

Plants’ Needs

Plants have different “appetites”: some are frugal like garlic, others are greedy like cabbage. They also don’t draw the same quantity or the same nutrients from the soil. Moreover, certain plants can enrich the earth, like fabaceae (peas, beans, broad beans…) which fix atmospheric nitrogen. Crop rotation therefore ensures that all vegetable plants receive, in due time, the right quantity of essential elements for their growth.

Preventing Diseases and Pests

Many pests and diseases are specific to one species or botanical family (Clubroot, Downy Mildew of Compositae, Carrot Fly…) and can persist in the soil for several years. Thus, rotating plants from different botanical families helps prevent these diseases or parasitic attacks from becoming chronic.

Field beans fix atmospheric nitrogen

How to do it?

In the garden, crop rotation is carried out according to the type of vegetable (seed -> leaf -> root -> fruit) while ensuring not to follow one vegetable with another from the same botanical family, and respecting the plants’ fertilisation needs (intermediate applications are possible).

Here are two examples of crop rotations:

Plot A:

• 1) Seed vegetable: Peas (Fabaceae)
• 2) Leaf vegetable: Lettuces (Asteraceae) followed by a moderate compost application
• 3) Root vegetable: Potatoes (Solanaceae) followed by a moderate compost application
• 4) Fruit vegetable: Cucumber (Cucurbitaceae)

Plot B:

• 1) Root vegetable: Beetroot (Chenopodiaceae) after a moderate compost application,
• 2) Fruit vegetable: Tomato (Solanaceae)
• 3) Seed vegetable: Broad bean (Fabaceae) followed by a substantial compost application
• 4) Leaf vegetable: Cabbages (Brassicaceae)

If planning your vegetable garden’s crop rotation several years in advance isn’t possible, it’s important to keep, for each plot, a written record of where vegetables were planted as well as organic matter applications, to ensure optimal succession of crops.

Note that perennial vegetables (strawberries, artichokes, asparagus…) aren’t included in rotation cycles. However, when renewing plantings, the rotation principle is respected by extending the duration up to 8 or even 10 years.