Spearmint Brown Spots
Answered by: Inge Poot
Question from: Jessica Chapa
Posted on: December 07, 2007

I am growing "The Best" spearmint and have been noticing brown spots along and near the tips of leaves. I was just picking off the affected leaves, but I am now seeing it on new growth tips. I have had to do recent changes to my plants... I used diatomaceous earth to combat any slugs and I have moved these plants into the greenhouse.

I am assuming that your plants were in your home and that the browning occurred before you moved them to the greenhouse.

It could be that the roots did not keep up with the loss of water in the dry home environment and the leaves are therefore drying out in patches. Moving the plants into the moister greenhouse environment should correct this. If it doesn’t then I suspect a soil problem. You may have a drainage problem or you may have an excessive salt buildup. Make sure that water is freely allowed to drain from the container that the plants are in. If after a thorough watering water doesn’t drain out the bottom within seconds then drainage may need to be improved. If the drainage is okay, then try leaching the pot for several hours to remove excess salts: you can do this by placing the pot under an open faucet for an hour or two.

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