Crop rotation is a simple and natural way to improve the structure of garden soil. Rotating the planting location of each vegetable every year will increase garden soil fertility, reduce instances of plant disease, reduce pest problems, prevent the depletion of soil nutrients and help prevent soil compaction. Out of healthy soil grows healthy plants, and rotating the garden crops each growing season is the key to improving soil structure.
Potato Pathogens
Potato pathogens provide a good example of how crop rotation keeps garden soil healthy. In one growing season, the fungi that causes scabby skin patches on potatoes will increase rapidly in the soil. Crop-destroying, potato-loving nematodes will also rapidly increase in the soil.
The first year’s potato harvest will be unscathed by the fungi and nematodes, but the pathogens will remain in the garden soil. If potatoes are planted in that same location next year, the pathogens will then attack with a vengeance and destroy the entire crop. All the damage will be taking place underground and you will be unaware of it until harvest time. Now, what if you can prevent this from occurring?
Three Year Rule
The damaging pathogens must be starved to death and the soil structure improved by planting a completely unrelated garden vegetable where the potatoes grew last year. And the year after that, something beside potatoes should be planted in that location.
This scenario plays out with all vegetables; just the damaging organisms and pests have different names and shapes.
Follow the three year rule for all garden crops so soil structure will remain fertile, well-draining, and free of crop-destroying pathogens. Rotate crops each year so that the same family of vegetable is not grown in the same place for three years. That gives enough time for soil pathogens to die off, and the soil to be healthy enough to sustain the crop planted.
Good Crops
All growing crops take from the soil, but some also give back and improve the soil. For example, sweet corn grow deep roots which help break up compacted soil and improve drainage. Legumes and nasturtiums add nitrogen to the soil, and broad-leafed greens suppress weed growth and germination of any weed seeds lingering in the soil. Choose from a diverse group for your planting needs, and plant them as companion plants if possible.
Companion Planting
What is companion planting? Companion planting is the planting of different types of plants or crops close to each other in order to improve various aspects such as pest control and maximizing the soil. Companion planting, combined with crop rotation, will help to naturally protect an organic garden from both above ground and below ground pests. For example, planting marigolds near your crops can attract and draw potential pests away from them. Both companion planting and crop rotation also help improve soil structure naturally, so plants will have a healthier place to put down roots.