Q: My magnolia is showing signs of some kind of fungus damage. What can I do?
A: Continuous hot weather and heavy rains have set up our gardens for fungus problems. Fungus issues are directly related to temperature, moisture in the air and soil moisture levels.
These conditions are hard to remedy. How can your soil dry out if it is raining three times a week?
You must attack fungus problems in a consistent and thorough manner. First, fungus will often attack weaker plants or plants with damaged areas. Open tree wounds are an invitation for fungus problems. Even smaller plants, like perennials will succumb to fungus if they have been damaged by wind or insects.
In between our routine rainstorms, check your plants for broken branches or stems. Rotting leaves and piles of detritus from local windstorms should be cleaned up immediately. These materials can harbor fungal spores and may continually re-infect weakened plants. A large tree like a magnolia should have all damaged branches removed.
During hot, wet weather, gardeners should be raking and cleaning beds of all rotting material. Keep the areas around plants as clean as possible.
After you remove detritus, spray the soil or mulch with a fungicide. If you have severe fungus problems, you may want to completely replace your mulch with new clean wood chips.
Dip your clippers or hand-saw in a mixture of half water and half bleach to sterilize the implement. Wash any pruning tools after every use. Then you can spray all branches and the main trunk thoroughly with a fungicide.
Do not fertilize plants, trees or flowers that are suffering from fungus attack. Weak new growth only provides fodder for the fungus. Wait until the weather improves, dryer and perhaps cooler, before you begin to do any fertilization that will stimulate growth.
Fungus problems can kill smaller plants. They rarely kill a large tree, but they can create unsightly damage. Trim your tree, keep the area clean and wait for the weather to improve.
Email Pat Lea at firstname.lastname@example.org.