Extremely clean growing area always helps, put some Tanglefoot around the lips of your pots, if you do get them use Einstein Neem oil(cold pressed}... Good Luck.
Oh, I get spider mites all the time, regularly, due to my grow in the shed, and because I routinely let the plants out in the sun. I've been very successful with a combination of neem oil and carbon dioxide. I first hit them with 70 minutes of CO2, released from a 20# tank through a 1/4 hose at some slow level. A total guess. This really kills off the living mites -- mite carcasses are all over the place afterwards. Now I have no way, no way at all, to measure CO2 concentrations in my 7' x 8' x 8' grow area, but I've experimented with shorter duration blasts with no effect. 70 minutes works for me. I know there are dangers of doing so, because I really have no idea the concentrations I'm creating; I spend no time in the room afterwards, just enough time to close the valve. I don't fall asleep on the growroom floor. However, there's detailed info in Cervantes's and Rosenthal's books about the exact concentrations (5,000 ppm?) and durations (30 min?) needed to kill them -- presuming you've a CO2 meter to measure. A 20# tank of CO2 at Airgas is ~30 bucks, and my 70 minute release is ~1/3rd the tank -- I may be off ten bucks on either side, I don't remember exactly. I then apply neem oil per label directions three times, each about seven days apart to kill off the already laid eggs that want to hatch and any bugs that want to try to lay eggs. Neem oil doesn't kill off living bugs per se -- it's more effective by "confusing" living bugs to not lay eggs, and to prevent eggs from hatching into viable organisms. So if you apply neem and are pissed that it doesn't kill them off immediately, as I initially was, you just need to understand how it works. This combination has always worked for me. Always. As for taste due to neem, well, I don't smoke, so I cannot comment. I would say that I don't apply it during my flush regardless, and just accept that if they are present after earlier rounds of neem/CO2, well, then their carcasses will just be smoked alongside.
That is interesting about using high CO2 killing off the mites. Makes sense. Also Neem Oil works very well, however, it is not good to use late into the grow if you cannot wash it off completly because it will leave a very distinct and bad taste on the buds. Check out the threads on here about using a sulpher burner to kill them off. I have not tried it but it looks like it would be very effective.
hot shot No pest strip... six dollars at home depot and lowes.. place it at the base of your plant... problem solved
In looking back at old posts on these, it appears these hot shot no pest strips work by emitting vapors, not in the sense that these work like a traditional pest "strip" where the bugs find their way to the strip then either die, get stuck, can't get out, etc. A source of confusion on exactly how these things work. So apply at the base and allow the chemicals to do their thing? If I understand right, the active insecticide used to be dichlorvos but isn't any longer. Then my questions start coming -- what is the active insecticide(s), is it OK during bloom, during the last few weeks of flowering, does it impart taste, how long is it effective, can one work for the whole room or is it one per plant, will it last long enough to kill off existing eggs if an infestation is already present? From what I've read I think they'll last 4 months for a good sized room, but I don't know how this may apply to an actual grow room. While I may not elect to use this based on general unease regarding chemicalia, this nonetheless looks like a viable solution to mites. Any experiences to share would be great!