The importance of rotating vegetable crops to keep soil in good heart and avoids disease build up has been know for millennia. Gardeners should rotate families of similar vegetable using the lists below, not just switching for cabbages to cauliflowers.
Vegetables from the same family often need similar culture or treatment and suffer from similar pests. Fresh soil helps.

Families of like vegetables need similar nutrient levels and attach importance to different fertilizers.

Cucurbitacea – the marrow family

• Marrows and Courgettes
• Pumkins and Squashes
• Melons
• Cucumber

Leguminosae – Fabacea

• Broad bean, Runner bean and French bean
• Alfalfa, Tares and Trefoil
• Peas and Mange tout
• Clover, Lupins and Fenugreek

Compositae – Daisy Family

• Chicory – Endive
• Jerusalem Artichoke
• Lettuce
• Salsify and scorzonera

Cruciferae – Cabbage or Brassica family

• Broccoli, Calabrese and Kales
• Brussel Sprouts
• Cabbage
• Cauilflower
• Kohlrabi, Swede and Turnip
• Raddish and Mustard
• Oriental brassicas

Solanaceae – Potato Family

• Potato
• Tomato
• Aubergine
• Pepper

Umbelliferae – Apiacae

• Carrot
• Celeriac and Celery
• Fennel and Parsley
• Parsnip

Alliaceae – Onion Family

• Garlic
• Leek
• Onion and Shallot

Chenopodiaceae – Beetroot Family

• Spinach
• Beetroot
• Swiss Chard and Spinach Beet.
• Good King Henry and Quinos

Other unclassified vegetable families include Zea maize Sweet Corn, Purslane, Lambs Lettuce, Convolvulaceae sweet potato, Labiateae basil, and Polygonaceae for rhubarb & sorrel.