Preventing a Spider Mite Infestation in your Garden
PREVENTING SPIDER MITE INFESTATIONS:
Q: I just got rid of a bad spidermite infestation, and I'm getting ready to start over with new plants. I want to do whatever it takes not to get another infestation on my next crop. How should I proceed?
A: If your garden is contained in a room, it makes sense to treat the entire room. If you're using a grow-tent, I'd treat the tent itself and the surrounding area.
When spider-mites get to a certain level of infestation, they have a built-in survival instinct where egg laden females crawl off to non plant areas and go dormant for up to 6 months (as the 'legend' goes anyway). Then when conditions get perfect, they come back out in search of plants again.
The time tested method for treating a room is a bleach/water mixture applied everywhere. Be careful not to breath in any of the mixture or get any in your eyes as this could obviously have negative effects. Also be cautious about not applying the bleach mixture to anything that could be damaged, like fabric (tent material?) or carpeting.
Another possible approach is a product we sell called Mighty Wash. It has an instant kill on contact effect on mites and their eggs, so treating a room from top to bottom with Mighty Wash may be even better than the bleach mixture. It's definitely safer than bleach, but also quite a bit more expensive. Anything that resides in the proximity of the plants, or consistently comes into contact with the plant area should be considered for treatment as well, like clothing, tools, plant containers, hydroponics system, lights and fans, or whatever- because any of these items may have mites or eggs on them just waiting to make your life hell again.
Now's also a good time to get really paranoid about not bringing any mites back into the area.
In a commercial greenhouse, workers have to go through a special process before they enter the greenhouse. They put on Tyvek lab coats, hair and shoe covers, and wash their hands thoroughly prior to entry.
It may not be necessary to go to these extremes, but now that you've experienced a spider-mite infestation, it probably does start to make sense to take some precautions. We are always the carriers of our own infestations in one way or another, and anything you can do to catch a problem before it starts will make your life a lot easier in the long run, even if it means incorporating some inconvenient processes in the meantime.