I found two citrus plants in my collection with a lot of scales. I sprayed them with oil and hope to get rid of, in former times, with only one lemon I had good results. But now I found still at two other plants in my collection a single scale, which I removed by hand.
Now I ask me if I should spry before overwintering all my citrus (ca. 70 pots)? I will overwinter them by 1 ° C in a greenhouse).
Who have good experiences how to protect, prevent scales.
Thank you Frank