Q.Unusual Colouring On Herbs
Hello, Our rosemary, sage and mint grow beside each other and are all three affected. The lemon balm is not affected. The leaves have a discolouration of yellow spots. I’ve attached a photograph which I hope shows the affliction clearly enough. Is this being caused by something in the soil?
Certified GKH Gardening Expert
Hard to tell if this is aphids, a fungus or just a lack of nitrogen in your soil. I suggest treating them a few times with neem oil, and add a bit of nitrogen to their soil. I'm suspecting an infestation that just doesn't bother lemon balm. Here's a helpful article:
https://www.gardeningknowhow.com/edible/herbs/hgen/herb-growing-problems.htm