I have the same thing on my Crepe Myrtle. I believe that these are lichens, not scale. Lichens are harmless, but also will indicate the health of the plant is not up to par. Search on Google for "Lichens on Gardenias" and you should be able to find a picture to compare.
Thanks! You are right, and they are on my crepe myrtle also. Yuck!
I agree with Connie, those are lichens and they are not the cause of your problems. What little I can see of your leaves, indicate some sooty mold on the leaves and that is probably caused by a sucking/boring type insect, maybe aphids. It is also possible that you have too much water? Can't really tell that from the picture. Can you provide a full shrub picture and maybe a shot of one of the leaves? Right now my advice is to spray some Neem Oil, and or maybe some insecticidal soap.
Yes indeed that is a Lichen. Lichens are "autotrophs" which means they produce their own food like most other plants. Molds and Fungi do not...they steal "food' from their hosts. A lichen is a symbiotic relationship between fungi and blue green algae or cyanobacteria.
consider fertilizing more often to force on new leaves, which will naturally shade out the lichens
you can also just peel these off the branches...lichens are not some toxic mess...in fact some are used as food. ( just don't eat these)
excellent choices as he pix is very vague - plus oganic also. for aphids i've used Dawn dishwashing detergent and water and applied it as a foliar solutions
My gardenia has a tendency to get scale, which will leave the sooty mold behind. I treat the gardenia tree annually with a spectracide, the type that includes the plant food, is mixed with water and poured around the shrubs where the feeder roots can take it in. I've not had any issues with aphids or scale since beginning this annual routine.
Check with your Extension Office or your closest University with Hort/Ag Programs. They will be the perfect source for solutions in your particular area
I have never lived in an area with gardenias, but I think you can scrape off the licen and spray with a mix of baking soda and water to change the PH.
one can also make a mild solution of household ammonia and water to be used as a spray applied directly to the affected area. The mild ammonia will not harm your plants.
I had the same problem. I just washed it of with water. I had to do it 3 times after that, but know it stays away and the gardenia recovered the year after.
When any sort of a plant develops something like this, be it sooty black mould, or the scale that you have, it usually means that the plant is under stress. Too much water, too little, not enough fertilizer. If I remember correctly Gardenias like an acid type of food? Are the leaves (some of them) yellowing? I have quite a few in my front garden (Sydney) facing west (hot hot in summer). You can add a solution of epsom salts and water around the gardenia as an extra boost. Once, maybe twice a year. As I always advise, your local nursery is the best place to go, and because the problem could spread into the nursery if you take a piece of the plant with you (been there done that - scared the hell of one fellow when I took a plant in to the nursery with a mite infestation), take a photo. Good luck.
It's lichen and one thing it means is that you don't have any or at least very little air pollution where you live. They mainly seem to grow on older wood, I've not heard of them killing a tree. I have to say I think they are beautiful. They are very slow growing.
Sarah. County Kerry ( tons of the stuff here) Ireland
Congratulations the growth is lichen and Lichen only grows in the purest air. So You must live well away from polution. I would be so excited to find I had Lichen growing anywhere near my home. It will do no harm to your plants, but is the basis for a wonderful yellow dye if you are into homecrafts.
that grows on trees around here. some type of 'moss' 'lichen'. never seen or heard of it kill tree
You can try making some soapy water, and clean off with a soft cloth then rinse. It will not harm the plant. You can also spread some of the water around the plant. Another trick you can use is coffee grinds. You can mix it with the soil. It keeps snails, bugs and other insects that can cause that kind of mold. Hope this helps. BELINDA
It won't do any thing to your trees! We have it growing on the healthiest oak trees. I pull some off and use it on all kinds of projects.