Fungus on Mint
Answered by: Inge Poot
Question from: Jackie Wetzstein
Posted on: July 04, 2006

I wonder if you could help me out. In our herb garden, every year we get what appears to be a fungus, especially on the spearmint. I cut the fungus off, and try to pull the plant out. Then by the end of the season it has spread to the bee balm. Can you recommend a natural remedy for it?

You do not describe the fungus and so I have to guess that it may be powdery mildew. Cutting off the affected parts cut down on the spores available to be washed or blown onto other plants and is therefore a good idea. Spray the plants regularly and frequently with dishwashing detergent solution or insecticidal soap - both, but the latter more so, will also get rid of mites that could spread the infection and provide entrance holes for the fungal hyphae. Make sure you do any spraying or watering in the morning -of sunny days only, to cut down on moisture on the leaves which the spores use to germinate. The soap will wash off the waxy protection on the fungus and the sun will then be able to dry the fungus enough to make it die. In the fall cut off all foliage of infected plants and burn -do not compost, since the over-wintering spores will come from the compost heap in the spring!

If the soap does not do the trick, try a suspension of sulphur powder (called, strangely enough, "flower" of sulphur)or as a last resort neem oil -soap-water spray, since neem oil too has some fungicidal properties.

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