I found spider mites on a container-planted dahlia (or rather that's what my nursery said it was - I honestly couldn't see anything that looked like a mite or any evidence such as webby material). I isolated the plant and treated it with Neem Oil, but it was too late. When I sprayed the dahlia, I also sprayed all my other plants (all planted in pots). I've continued to do so every two weeks, even though I see no evidence of any kind of pests. Does Neem Oil (or soapy water) act as a deterrent, or preventive, against pests, or am I just making my life more complicated?
