Knowledgebase
Hard scale infestation management #879844
Asked August 02, 2024, 12:23 AM EDT
Lorain County Ohio
Expert Response
Hi Margarit,
I apologize for being late,
I saw your question on 8/2 but when I went to my computer it was gone! Luckily the administrator resent it to me.
I do not know what type of bushes you have so I will address general scale elimination. There are thousands of species of scale and the cycle is the same. By now you have scale that has become hard shelled. At this point no insecticide is effective and that makes it difficult.
After careful inspection remove all of the infected leaves and the worst branches. Do not use these in compost but dispose of them.
Wash with horticulture oil or insecticide soap and wash all the branches and leaves, top and bottom. After rains you may have to reapply. Follow the instructions on the product closely.
Make sure the bushes get plenty of water and clean up the underbrush and old leaves. If you see small wasps or lady bugs that is great because along with soldier beetles these are beneficial insects who will assist in getting rid of the scale. If you notice ants around the main stem and along the trunk they are after the honeydew of the scale and pest barrier can be applied around the stem or trunk.
A great resource is the OSU Extension Office at 42110 Russia Rd, Elyria, Ohio 43035.<personal data hidden>. If you go to https://ohioline.osu.edu and search fact sheets online you will find more information on scale. A good local nursery will have the materials I suggested.
I have battled scale on my Magnolia bushes. Start looking in early spring under all the leaves to get them early.
I hope I have been helpful and not too chatty.
Sincerely,
Mike Heys, Franklin County Master Gardener
Hi Mike,
Thank you for responding. I researched products that could manage the scale in the “hard” stage and found the product Transtect, but I became concerned about its toxicity. I wasn’t sure if I could use the horticulture oil with the temperatures in the 80s. I have the product and will follow your instructions. I think they are burning bushes. They were on the property when purchased.
Margaret Stasik
From: ask=<personal data hidden> <ask=<personal data hidden>> On Behalf Of Ask Extension
Sent: Monday, August 5, 2024 6:59 PM
To: Margaret Stasik <<personal data hidden>>
Subject: Re: Hard scale infestation management (#0149762)
Good Evening Margaret,
I gave you more organic instructions due to toxicity that many want to avoid and because systematic insecticides are less effective against the hard scale stage. If that is your choice still remove the heaviest damage foliage and branches and clean up around the bushes and water.
This might be a problem in the future also. Keep a sharp lookout early next spring.
Best of luck.
Mike Heys, Franklin County Master Gardener
