This azalea plant(Karen v... - Ask Extension
This azalea plant(Karen variety?, August 11, 2014, 3 ft diameter and 28 inches tall) is several years old on the southwest side of house but under Map...
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This azalea plant(Karen v... #219425
Asked November 04, 2014, 6:53 PM EST
This azalea plant(Karen variety?, August 11, 2014, 3 ft diameter and 28 inches tall) is several years old on the southwest side of house but under Maple tree shade. Deer have not found it as much as others!! It is off color most of the time. Is this insect damage - I have more photos of parts of the plant. I have tried to fertilizer it with both organic Holly Tone and chemical fertilizers. I have sprayed it at times and it can look more damaged at times. I can try for more sunlight. I just do not know where to start to improve it. Another plant has improved elsewhere with sun and fertilizer(?). Deer have killed others by browsing. Are coffee grounds good for it? You can see some on the ground.
What additional information do you need? I need to watch for spring flowers; I do not think the deer have been eating the buds on this one but maybe.
Howard County Maryland
Expert Response
There are several reasons why azalea leaves turn yellow. The most common reason is lace bug feeding. Lace bugs (hiding under the leaves) insert their mouth part into the leave and suck out the interior. The marks they cause are called stippling. Please look at the photos from our website pub on azaleas and rhododendrons then check under the leaves of your azalea: http://extension.umd.edu/learn/ipm-series-azaleas-and-rhododendrons-hg51
You'll notice that the underside of the leaf gets very dirty looking from the lace bugs and their excrement. The pub above and the following pub give directions for control:http://extension.umd.edu/learn/lace-bug-hg95
In the first pub you'll also see the other cause of leaf yellowing. Because your azalea is almost surrounded by cement foundation which can leech and make the soil pH higher, that may be making high pH a problem. Solve that by lowering the pH--(see the pub.)
Fertilizer is not medicine and cannot usually solve problems unless the soil is lacking a particular element, which is not often the cause of problems. If lace bugs or high ph are not the problems, and/or to get an accurate reading of the pH, you may want to get the soil there tested. Soil testing information is on our home page under the photo.
ECN
You'll notice that the underside of the leaf gets very dirty looking from the lace bugs and their excrement. The pub above and the following pub give directions for control:http://extension.umd.edu/learn/lace-bug-hg95
In the first pub you'll also see the other cause of leaf yellowing. Because your azalea is almost surrounded by cement foundation which can leech and make the soil pH higher, that may be making high pH a problem. Solve that by lowering the pH--(see the pub.)
Fertilizer is not medicine and cannot usually solve problems unless the soil is lacking a particular element, which is not often the cause of problems. If lace bugs or high ph are not the problems, and/or to get an accurate reading of the pH, you may want to get the soil there tested. Soil testing information is on our home page under the photo.
ECN
