Volck Oil Spray 

Question

Is Ortho's Volck Oil Spray safe to use on my orchids? I have white scale on several of my cattleyas and nothing I have used seems to solve the problem. The label states that this product is not to be used on maidenhair ferns, red maples, Japanese maples or nonwoody plants. Since the cattleyas are certainly nonwoody, could a weak solution be applied safely? —Marie B. Lambert
 

Answer

I do not have any direct experience with this product on orchids, but it is my feeling that since it is an older product, it may not be too safe for sensitive plants. It can cause phototoxicity so if you do use it, make sure it is during the coolest part of the day. Really, the only thing that has ever proven successful on the white boisduval scale has been Cygon (dimethoate). It is not labeled for orchids so we cannot recommend its use. One control for boisduval that I have used is a mixture of Safers Insecticidal soap and Sunspray horticultural oil at full strength. It takes several applications, and it is definitely a control rather than eradication, but it seemed to succeed for me. Boisudval is very hard to get rid of, so this will take some persevering on your part. —Ned Nash