Heyy, first post. I was about to put my shimpaku juniper into the garage for winter when I noticed it has what appears to be a scale infestation. The picture included shows what's happening all over the tree unfortunately. Just wondering if anyone could suggest some kind of treatment, given that it's early December? Didn't know if certain insecticides were a bad idea in the winter. Any advice at all would be greatly appreciated
Please keep in mind that if you use an insecticide with oil or soap it is a good idea to rinse off the foliage in 24 hours so the plant can breathe again. Also some insecticides are not suitable for juniper, so check labels before using. You may need to change the dosage or product.
Scale is one of the more difficult to control insects, for a situation like that I would want to use a systemic but the time of year with dormancy is not conducive to that approach.
I would recommend a solution of soap and alcohol with q-tip application on the worst areas, if spraying then saturate above and below, get the undersides of the foliage as well and rinse 24 hours after application.
One recipe suggested is as follows: two drops of liquid dish soap one cup of warm water and one teaspoon of rubbing alcohol.
* Taken from Bonsai Today's Master Series " Junipers"
For dish soap a good choice is Dawn liquid detergent "original".
For insecticide it usually boils down to what is available to you in your location for the particular purpose.