Crop Rotation In The Vegetable Garden
The term "crop rotation" refers to planting different vegetables in different spots on the same land from year to year. In other words, for best results with your vegetable garden, related vegetables should not be planted in the same spot every year. For example, squash should not be followed with a related vegetable such as watermelon, cantaloupe, or cucumber. 

Crop rotation has been used by farmers for many years. The practice of rotation helps minimize insect and disease problems and helps maintain soil fertility. Certain families of plants are subject to the same diseases and should not be planted in the same area more than once every 3 years to prevent the disease organisms from building up in the soil.

In the chart below, crops planted in Bed 1 are planted in Bed 2 the following year, and in Bed 3 the year after that, and then Bed 4 and back to 1 again. If you don't plant a cool season crop of leafy vegetables, you can take a few plant types from Bed 1 and Bed 3 and place them in Bed 2. 

Rotating your crops in this manner helps to keep your soil makeup balanced, insects at a minimum, and your garden healthy. You will start to notice a healthy improvement in your garden produce.

Note:  Remember that potatoes are the unique vegetable here. While keeping them in a rotation plan, you'll want to be sure they're planted in a bed that has not previously grown tomatoes, peppers, or eggplant.

The concept is very simple. Keep a notebook of where your crops are planted from year to year. This is a sure fire way to keep your crop rotation in line.