Azalea Gall

Question: I have several 35 year old azaleas that have gall. Last year I sent in a photo of some white stuff on one of the branches and was told they were insect eggs. They were not, now I have full blown gall on several of my 35 year old azaleas. I have about 20 of them and half are affected. I pulled the leaves off that I could find, but there are more showing up every day. I don't want to lose these beautiful plants. What do you suggest for treatment? I have a dog so it has to be dog safe. I did spray it with baking soda and dawn soap a mixture I found on line. So far with no change. Any help to save these plants would be greatly appreciated. Thank you.

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 15, 2023, 4:37 PM EDT
response: We apologize if there was a misdiagnosis; perhaps we didn't see enough detail in an earlier photo if one was submitted. This is clearly Exobasidium gall, as you noted, and these types of galls are fairly common on azaleas and camellias in our area. Even though ideal conditions for infection involve cool and wet weather, and this spring was cooler than average but not wet, (though cooler temps. do promote more dew that can dampen foliage enough for infection), we have still received a few submissions about these galls from other gardeners.  These fungi do not cause serious damage to the plants and can be trimmed off as discovered and discarded. There are no fungicides suitable for prevention and none will cure existing infections anyway. Do not use a home remedy like dish soap mixtures as this risks causing phytotoxicity (plant tissue damage) on the treated plant as well as other secondary environmental damage since these ingredients are not intended for pesticide use. The shrubs in the photo appear to be in great condition and if any decline manifests going forward it won't be due to the Exobasidium presence.  Miri

responder: The Question Asker Replied June 15, 2023, 6:00 PM EDT
response: Thank you!Sent from my iPhone On Jun 15, 2023, at 4:37 PM, Ask Extension <<personal data hidden>> wrote:﻿

responder: The Question Asker Replied June 17, 2023, 12:52 PM EDT
response: Hi,I have another question. The leave shave spots, I will include a picture. Is this something else the azalea has and if so can I treat it? Thanks!Sent from my iPhone On Jun 15, 2023, at 4:37 PM, Ask Extension <<personal data hidden>> wrote:﻿

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 19, 2023, 9:46 AM EDT
response: This damage is caused by Lace Bugs, a very common insect pest on azaleas and other plants. (There are different species of lace bugs on other plants, so these won't necessarily spread to anything unrelated to the azaleas.) This amount of damage is minor and should not need treatment, but you can inspect leaf undersides to see how abundant the insects appear to be. The simplest approach is to blast them off the leaf undersides with a strong jet of water from a hose, especially since several kinds of beneficial insects as well as spiders will eat them. If necessary, you can try treating with a topical insecticide like horticultural oil or insecticidal soap, but the leaf undersides must be thoroughly coated (not easy to achieve), repeat treatments will be needed (as per product label directions), and sprays should not be made while temperatures are above 85 degrees due to the risk of phytotoxicity (plant tissue damage from chemical exposure).  Miri

responder: The Question Asker Replied June 19, 2023, 10:11 AM EDT
response: ﻿﻿Hi,Thanks so much for your reply. If I just leave it alone will it be ok? I have a dog and I hate spraying anything in the back where he plays. Thanks so much! Abby Sent from my iPhoneOn Jun 19, 2023, at 9:46 AM, Ask Extension <<personal data hidden>> wrote:﻿

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 19, 2023, 5:31 PM EDT
response: Hi Abby,  Yes, the plant should be fine given the relatively low level of lace bug damage that is visible. You can keep an eye on the plant from time to time this summer as lace bugs can produce several generations per year and azaleas that are exposed to more direct sunlight or which are heat/drought-stressed are more vulnerable to developing more prominent feeding damage. Leaves can't heal, so any existing damage will not go away once it occurs (though new growth over the years will cover it up or the plant will shed some of the worst-affected leaves in spring or autumn), but as long as it's not excessive damage, this is not a big concern.  Miri

responder: The Question Asker Replied June 19, 2023, 6:03 PM EDT
response: Thank you!On Jun 19, 2023, at 5:31 PM, Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 20, 2023, 8:49 AM EDT
response: You're welcome!