fungus on plants - Ask Extension
i have this fungus on my azaleas and a couple of other plants. can u please tell me what it is and how to get rid of it. it makes my plants look ugly.
Knowledgebase
fungus on plants #204278
Asked August 03, 2014, 12:30 PM EDT
i have this fungus on my azaleas and a couple of other plants. can u please tell me what it is and how to get rid of it. it makes my plants look ugly.
Barbour County Alabama
Expert Response
Good Morning,
Your azalea has lichens growing on it. Lichens don't actively try to hurt your azaleas, they just use the branches as a place to grow on.
Lichens are a combination of fungus and algae living in harmony. The algae makes sugars that the fungus needs and the fungus provides a safe haven for the algae, keeping it from drying out and providing it with nutrients.
Usually lichens are a minor problem for trees and shrubs. In your case it looks like the lichens are doing really well. This means that the azaleas are not doing well. As the shrub grows it stretches the bark, usually making the lichen break apart or fall off. If the azalea isn't growing well, then the lichen isn't interrupted and it keeps growing and can, in time, smother the azalea.
There are no chemical controls that will work well on this situation. Instead, you have to try to improve the health of your azalea.
1) Get a soil test kit from your local extension office and follow the instructions. The test will let you know if the soil is too acid, basic or has some other problem that can affect your azaleas. Azaleas like acid soils that are well drained but moist.
2) Check your azalea for any insect problems. Azaleas in our state have a number of pests but Azalea Lacebugs are a problem. They can severely weaken your shrubs. Only insecticides can stop them. Look for yellowy speckled leaves that have lots of pinhead sized black dots on the underside. A few here and there are no problem, some on all the foliage is bad. Here's an article for you about this:
http://www.aces.edu/pubs/docs/A/ANR-0193/ANR-0193.pdf
3) If the azalea in question is older and hasn't been pruned much in its life you can also just cut the shrub back to about 6 to 10 inches tall. This is called renovation pruning. It will remove all the branches with lichen. However, you will not have spring flowers next year as you'll be removing the flowerbuds set this year. You can, if you think the shrub can endure, wait until after flowering in 2015. Do not do this to the shrub right now. Wait until cool fall or winter weather.
4) Mulch and fertilize the azalea. Azaleas naturally live in very fertile areas with lots of leaf litter on the soil. remove any weeds and grass from around the shrub completely and mulch it. Fallen leaves, pinestraw, or store bought bark mulches are all acceptable . This will help keep the roots of the shrub moist and cool and as the organic matter breaks down, improve the soil fertility for the shrub..
Fertilize the azalea only if your soil test says to.
There is a lot to know about azaleas. I'll post another link after this that contains a lot of information. You want to read the culture and care information in the back of it.
The lichens are there because the azalea isn't growing well and doesn't have a dense canopy of leaves to shade out the lichen itself. Doing everything you can to improve the azalea health will begin to reverse the lichen. You can also remove the old branches and start over with an azalea but, be sure your shrub is able to handle such a harsh treatment.
http://www.aces.edu/pubs/docs/A/ANR-0200/ANR-0200.pdf
Also consider calling your local cooperative extension office at:
County Extension Coordinator
1 Court Square, Room 105
Clayton, AL 36016
Phone:<personal data hidden>
Your azalea has lichens growing on it. Lichens don't actively try to hurt your azaleas, they just use the branches as a place to grow on.
Lichens are a combination of fungus and algae living in harmony. The algae makes sugars that the fungus needs and the fungus provides a safe haven for the algae, keeping it from drying out and providing it with nutrients.
Usually lichens are a minor problem for trees and shrubs. In your case it looks like the lichens are doing really well. This means that the azaleas are not doing well. As the shrub grows it stretches the bark, usually making the lichen break apart or fall off. If the azalea isn't growing well, then the lichen isn't interrupted and it keeps growing and can, in time, smother the azalea.
There are no chemical controls that will work well on this situation. Instead, you have to try to improve the health of your azalea.
1) Get a soil test kit from your local extension office and follow the instructions. The test will let you know if the soil is too acid, basic or has some other problem that can affect your azaleas. Azaleas like acid soils that are well drained but moist.
2) Check your azalea for any insect problems. Azaleas in our state have a number of pests but Azalea Lacebugs are a problem. They can severely weaken your shrubs. Only insecticides can stop them. Look for yellowy speckled leaves that have lots of pinhead sized black dots on the underside. A few here and there are no problem, some on all the foliage is bad. Here's an article for you about this:
http://www.aces.edu/pubs/docs/A/ANR-0193/ANR-0193.pdf
3) If the azalea in question is older and hasn't been pruned much in its life you can also just cut the shrub back to about 6 to 10 inches tall. This is called renovation pruning. It will remove all the branches with lichen. However, you will not have spring flowers next year as you'll be removing the flowerbuds set this year. You can, if you think the shrub can endure, wait until after flowering in 2015. Do not do this to the shrub right now. Wait until cool fall or winter weather.
4) Mulch and fertilize the azalea. Azaleas naturally live in very fertile areas with lots of leaf litter on the soil. remove any weeds and grass from around the shrub completely and mulch it. Fallen leaves, pinestraw, or store bought bark mulches are all acceptable . This will help keep the roots of the shrub moist and cool and as the organic matter breaks down, improve the soil fertility for the shrub..
Fertilize the azalea only if your soil test says to.
There is a lot to know about azaleas. I'll post another link after this that contains a lot of information. You want to read the culture and care information in the back of it.
The lichens are there because the azalea isn't growing well and doesn't have a dense canopy of leaves to shade out the lichen itself. Doing everything you can to improve the azalea health will begin to reverse the lichen. You can also remove the old branches and start over with an azalea but, be sure your shrub is able to handle such a harsh treatment.
http://www.aces.edu/pubs/docs/A/ANR-0200/ANR-0200.pdf
Also consider calling your local cooperative extension office at:
County Extension Coordinator
1 Court Square, Room 105
Clayton, AL 36016
Phone:<personal data hidden>
