Ok, thyme is one of my favorite herbs. It smells wonderfully and the best part is the fact that bees love it too. While thyme is normally pest and plant disease free, there are times when this plant finds itself under the weather. Below are some common pest and plant diseases that thyme can suffer from and to protect those bees the solution is organic.
Yes, thyme can suffer from spider mites especially when the plant is under stress. Prior to doing any treatment, one must first decide if spider mites are present. Since this pest is very small, the best approach is to shake the plant material over a white piece of paper. If you see little dots on the paper then you probably have spider mites. To treat this issue, first try to dislodge them with short bursts of water. If there are a lot present, consider removing the branch or stem they are sitting on and dispose of in a bag. While this technique will work, it can destroy the shape of your plant. Another approach to follow is to mix up a solution of 3 tablespoons dish soap to 1 gallon of water and place it in a spray bottle. Repeat this process every 6 days or until the spider mites are gone. When using this latter approach, make sure to rinse your thyme thoroughly before consuming.
Gray mold is a plant disease that is brought on by wet foliage. It will appear as water soaked spots on the leaves, which can turn brown. The spot will eventually rot through and cause the area to die. Not only is this unsightly but it can eventually kill the plant.
The first approach to control is prevention. What this means is that you properly space out your thyme and only water it in the morning. This will give the plant material time to dry before nightfall. Another technique is to keep the garden space clean. Finally, if you find this issue and it has taken over the plant material just remove it and start over. But when replanting, make sure that your thyme is not damaged. Healthy plants do not get gray mold.
Root rot is caused by a soil borne fungus. It attacks the young roots of the plant and will kill the plant if not caught early. How do you know if your thyme has root rot? Well, the first sign is a decline in the health of your plant but once you see this, it is normally too late. A better test is to take a look at the roots. To do this, simply remove the thyme from its container and wash off the soil around the roots. If you see roots that are black and mushy then you have root rot. But what do you do? If the disease has not progressed too far, you can just remove the mushy roots, dump the soil in the pot and spray off the roots to remove as much of the soil as possible. Once that is done, sterilize the pot in hot water with a capful of bleach. Allow the pot to soak and then scrub off the soil. Rinse in clear water and allow to dry.
The next step is to simply repot the plant. While this is easy, do not forget to add drainage material. A wet soil is a breeding ground for soil borne fungus. If the soil is left wet, you will develop root rot again. Also, make sure to only use sterilized soil.