As I work on planning the garden one aspect is picking what kind and varieties of each plant will we grow, the other aspect is placement. A big factor in placement is to consider what was grown there last year. Crop rotation makes sure that plants of the same family are not planted in the same spot year after year. Some plant diseases and pests live in the soil, if planted in the same spot year after year the same issues will ensue each year. By switching around plant families which have different diseases and pests you will help to increase the likelihood of healthy plants.
I have heard all sorts of ideas about crop rotation. One theory is that you should be on a five year rotation or some say a seven year rotation. Maybe a farm has room for a seven year rotation but I am going to be happy if I can figure out a good three year rotation. Last year it was easy to flip flop the placement of the plants. This year is going to be a bit trickier in terms of planning. I don't want to flip flop the plants back to their placement two years ago, luckily with the possibility of creating more beds that will solve the rotation issue.
Some people just figure it out year to year how they will rotate their plants. However others have a real science to it. This Fall I read about the Bio-Dynamic Method of crop rotation which has a four season rotation. Their rotation is based on five main plant families, here is what they say:
Season 1 - Grow solonaceae (potatoes and tomatoes) which are nutrient hogs.
- In the Fall replace them with brassicaceae (cabbages, broccoli, cauliflower) which will take away the food source for solonaceae fungal issues and pests.
Season 2 - Follow with apiaceae (root veggies).
Season 3 - Plant leguminosae (legumes, peas, beans) which replenish nitrogen levels in the soil.
Season 4 - In the last year plant asteraceae (lettuce and salad crops) which can grow well in depleted soil and will do well with the nitrogen left behind by the legumes.
Then when season 4 is over apply compost, manure or other amendments and start the rotation over.