“Of all the ugly things, nothing is worse than the variegated conifer, which usually perishes as soon as all its variegated parts die, the half dead tree often becoming a bush full of wisps of hay.”
William Robinson ,The English Flower Garden (sixth edition, 1898).
Crop rotation has been followed for many hundreds of years for good reasons. Those medieval agriculturists knew a thing or two when they practiced crop rotation, including a fallow year – one in seven, if my memory serves me right. Planting quick maturing green crops and using compost can remove the need for the fallow year (which was all about returning fertility to the soils). The crop rotation part remains important because if you keep planting the same type of vegetables in the same place every year, you will get a build up of pests and diseases.
There is a wealth of information on crop rotation, but in its simplest form, think about plant families, not individual vegetables. There are the solanums (potatoes, capsicums, aubergines, tomatoes), the brassicas, (cabbage, cauliflower, Brussel sprouts, many of the Asian greens and broccoli), legumes (peas and beans), other leafy greens and beets, alliums (onions and garlic), the carrot, celery and parsley family of Apiaceae (or Umbelliferae), and the cucurbits (pumpkin, cucumber, courgettes, melons).
There are six families above plus a few like sweet corn which don’t fit anywhere. Rotate them round the veg patch every year and you will get a break of several years (minimum of four is desirable) before they end up back in the same spot. That simple process will greatly reduce your need to resort to intervention with sprays and powders.
If it all sounds too complicated, just keep the brassicas and the solanums moving. They are the most vulnerable crops.
First published in the Waikato Times and reprinted here with their permission.