Hi
I have had a lovely lawn-like area of elfin thyme in my garden for about 2 1/2 years. It's on a low water drip system and has been beautiful in a walkway area and a heart shaped lawn area. This summer it began getting black spots and it spread to completely kill the whole heart area (maybe 150 sq feet?) and part of the walkway thyme. I am so sad. I've begun ripping out the black parts now and have been told by the UC Extension office here in my town that using Neem oil on the remaining thyme should save it...they think it's a fungus of some sort. I just want to confirm that this is the right thing to be doing. Does Neem have any side affects for the animals/ bees etc that might not be good. I do not want to do anything that is far from organic gardening. I bought the Neem at an organic nursery and they said as long as I user it after dusk when the bees are not active, that it would not affect them the next day. Can you please confirm?
Thank you!

Answer #1 · Maple Tree's Answer · Hi Nancy-I believe your Extension Service is correct in that this is some type of fungal disease. Once established the thymes prefer medium to dry soil that is well draining. Too wet a soil along with high humidity conditions can easily cause the thyme to rot. Too wet a condition will turn the leaves black causing the plants to slowly die. I had this same thing happen a few years ago in my rock garden when sprinklers weren't monitored during the planting of other ground covers in the same area. Neem oil is all I use in my gardens for fungal disease and some pest control. It is safe to use and will not hurt our pets and our beneficial insects such as the bees. I try to spray early in the morning before most beneficial insects have not started moving around for the day. It also gives time for the treatment to dry so that the plant leaves are not wet all night which can add to any fungal disease. Having a drip system is great as overhead watering can definitely add to fungal diseases keeping the leave wet for periods of time. I would first check the soil making sure watering or rain has not kept the soil too wet. I'm thinking watering much less should make a difference especially now that the plants growth will be slowing down for winter and the soil will be staying moist for a longer period of time.

General facts regarding Neem oil

http://npic.orst.edu/factsheets/neemgen.html

Please ask if you have any other questions and let me know what you find when checking the soil for too much moisture.

John)