Do you practice crop rotation in your vegetable garden?
Each vegetable family has its own nutritional and growing requirements and pest and disease problems. Some vegetables have greater demands on the soil than others. Tomatoes, a member of the Solanaceae (Nightshade) family, require a soil-rich in nutrients to grow successfully. After harvest and cleanup, the soil is left depleted of nutrients, making it incapable of successfully supporting another heavy feeding crop, like tomatoes, peppers, potatoes and eggplant.
In addition, if your crop experienced a disease or pest problem and another member of the same plant family was planted there the following gardening year, it too may become susceptible to disease.
For this post, I have created a vegetable families chart to make it easier for you to identify the various vegetables that belong to each family. When planning out your gardens, use this chart to plan your crop rotations for individual vegetables and entire families.
How to Use the Vegetable Families Chart:
When you look at the chart, the leftmost column is the name of the plant family, i.e. Cucurbitaceae. To the right of the plant family name, written horizontally, is a list of vegetables and herbs, corresponding to that plant family.
Some families have higher nutritional demands on the soil than others. For example, the Solanaceae family consists of tomatoes, potatoes, eggplant and peppers. All heavy feeding crops. However, Fabaceae, or the Legume family, consists of beans, peas, peanuts and runner beans. All nitrogen-fixing crops. These crops don’t tax the soil of nutrients, but instead help to replenish it by fixing nitrogen from the air, then creating nitrogen nodules on their roots. When legume crops break down and release these nitrogen nodules, they add nitrogen back to the soil.
If you grow a heavy feeding Solanaceous crop, follow it with a legume crop to help replenish the soil of lost nitrogen.
The Asteraceae family consists of lettuce, endive and other leafy green crops. These heavy feeding crops can be followed by a crop from the Apiaceae family, like carrots, parsnips, celery, dill or cilantro. A crop from the Amaryllidaceae or Allium family is also a good option.
Cucurbitaceae, consists of cucumbers, zucchini, squash and melons. It is another heavy feeding crop. Follow these crops in the following year or as a fall succession planting with a legume, allium, or crop of the Chenopodiaceae family.
Finally, it’s important to not only rotate your individual crops, but to rotate the entire crop family. If you grew potatoes last year, don’t plant tomatoes in the same spot. Solanaceous crops are heavy feeders that share similar diseases. Be sure to plan for a vegetable from a different crop family in the following year and find a new location in the garden for members of this family.
Consider working on a rotation plan. Divide your vegetable garden into 4 or more sections and plant different crop families within those sections. Then rotate each section to the next, with the last section moving into the first section, and so on. After 4 rotations (or 4 years), your beds will have replenished their nutrients and recovered from any diseases left behind in the soil.
Just be sure to select a less heavy feeding crop for the alternate sections. That way a heavy feeding crop moves into a section that hasn’t been depleted of nutrients in the previous year.
Section 1 – Solanaceae and Lamiaceae families
Section 2 – Fabaceae and Chenopodiaceae families
Section 3 – Cucurbitaceae and Asteraceae families
Section 4 – Amaryllidaceae (Alliums) and Apiaceae families
In year 2, rotate Section 1 into Section 2, section 2 into section 3 and so on. Section 4 will move into Section 1. Continue to move the sections according to this rotation for the following years. By year 5, Solanaceae and Lamiaceae will be back in their original positions in Section 1.
To speed recovery of your planting beds, top your soil with 2-inches of compost in the fall after harvest or in the spring prior to planting the next crop in the rotation. No need to stir it in. The earthworms will thank you by moving it for you.
If you haven’t practiced crop rotation in your garden plans, yet experienced weak growth in your vegetable plants, this may be a reason why. Take a look at your garden and divide it into sections. Then map out what you would like to plant and allocate it to each section. Then rotate your crops on a yearly rotation and you should experience stronger and healthier growth in your vegetable crops in following years.