If you aren’t familiar with soil-borne diseases, then you can count yourself as lucky.
Many (most?) microorganisms that live in our soil are harmless and quite possibly beneficial. However, there are also some that can cause significant damage to our plants and can even hang around in our soil for many, many years. These include fungi and bacteria that cause root rot and wilt diseases.
The best way to deal with soil-borne diseases is by preventing them on the front end, rather than trying to combat them in the middle of your growing season. Here are the top four ways, that we know of, to prevent soil diseases.
Top 4 Ways to Prevent Soil Diseases
1. Crop Rotation
We would say that crop rotation is the number one way to prevent soil diseases. A good rule of thumb, if you have the space, is to rotate your crops so that the same/similar crop is not in the same location for 3 years. For those of us that are urban farmers, this might be incredibly hard and/or impossible, but the closer you can get to this spacing, the better.
When rotating crops, this includes keeping crop “families” in mind, i.e. nightshades, cucurbits, brassicas, etc.
2. Have Good Garden Hygiene
This includes cleaning garden tools and pots. When starting seeds, we are very careful to clean all of the 4-inch pots – Plastic Pots for Plants, Cuttings & Seedlings we use thoroughly with a mild soap before planting new seeds. Seedlings are particularly sensitive to these soil diseases and if you lost a seedling in previous growing seasons to root rot (not incredibly uncommon), that disease may still be hanging around on the pot several seasons later.
3. Plant Disease-Resistant Crops
This may be controversial for some of you and no, we are not talking about planting GMO crops. However, some crop varieties have been bred and crossbred to be resistant to certain diseases, especially soil diseases. Obviously, there won’t be many (if any) heirloom varieties that fall into this category, but it is something to keep in mind if you’re open to the idea.
4. Don’t Overwater
Overly damp/wet plants are a playground for soil diseases, especially rot diseases. Make sure you are always planting in well-drained soil/pots. Also, if mulching, try not to mulch right up to the stem of the plant. Mulch at the plant stem holds moisture and promotes rot.
If you do get a soil-borne disease, you might have some trouble getting rid of it. The first step is identification, then treatment. Often soil solarization is a great idea, especially in my fair city of Phoenix, where summer heat renders my gardening useless. However, if you have a particularly terrible disease, replacing soil (if growing in a pot or raised bed) or moving your garden (if growing directly in the ground) may be necessary. Start with a master gardening group, local extension office or university to help with id and treatment.