To prevent diseases on the plants it is important to move the vegetables every year. This is also good for the soil as different vegetables need a different combination of nutrition and if you grow for example carrots on the same place every year you will eventually end up with a soil completely empty of the nutrition the carrots need.
An easy system is to divide you vegetables into four groups:
- Vegetables that need a lot of nutrition as cabbage, cauliflower, leek, tomatoes, cucumbers.
- Vegetables that don’t need a lot like root veggies, potatoes, lettuce, onion.
- Peas and beans which don’t need nitrogen, they get it from the air.
- Clover grown to enrich the soil. (Green manure)
Then divide your garden into four parts and let these groups rotate every year. It gives you three years of good crops and one year when the soil can rest. Using this rotation will make it easy for you to keep the soil fertile.