Spider mites can and will wreak havoc on crops if given the chance. If you find yourself in a spider mite position then the following tips can help.
Cleanliness of people/plants and the growspace itself is the top preventative. This step sounds easy but is far from it, as you find yourself in the growspace for plant/grow space maintenance, watering and general checks. Keeping clean can be hard but will reduce the risk of mite infestation. But as disheartening as it sounds it will not always work, it only takes one person/plant to introduce Mites into the grow space, and all of your hard work unfolds.
Do not put your indoor plants outside!!!
Majority of people spoken to regarding mite infestation have done one thing in common!!! and that is!! a few sunny days a week, take their indoor plants and put them outside for the day. If your doing this!! then you might as well find some spider mites in your garden and throw them into your indoor grow space. This includes seedlings and clones. Mites will wipe out young plants very fast.
Separate infested plants.
At the seedling and clone stage you can remove infested plants quite easily. You can spot a bad clone or seedling by its yellowing and drooping leaves, no point trying to revive these young plants as the longer you try keep them alive the higher the risk of infesting other plants. As plants get larger it becomes hard to seperate the infested plants and at this point! infestation has most likely taken over all crops.
Defoliation is a top tool that needs to be done! especially if your grow space is a tent, There are alot of articles online stating the benefits of both defoliating vs not. As far as removing leaves for mite management it works well. This step works very well with Foliage spraying, air movement and plant growth.
This step does not mean the spraying of pesticides but of PH corrected water with or without nutrient additives. As mites thrive in warm temps with low humidity, giving your indoor plants a frequent foliage spray will help disrupt the mite environment both on and off the plant.
A simple fan blowing over the plants will help with general air movement but also disrupt the mite environment on the plant.
Grow your plants
A good indoor grow environment will grow your plants sturdy enough to withstand mite attacks. What this means is not overcrowding your grow space with plants, but instead grow your plants to a size that can withstand unforeseen pests. i.e rather then having 9 plants in your grow tent, only grow 4 plants and train the 4 plants to fill the tent, once the plants are mature they are at a size that will withstand unforeseen circumstances.
Predatory mites are a very good weapon and is one additive we would recommend. Predator mites feed on spider mites and not the plants. If immediate attention is needed to eradicate mites then this step might not work for you! Predatory mites take a few weeks to start populating and operating, so your plant could be well done by that point.
Other preventatives are the adding of silica and mite spray.
Giving your plant silica will aid in the hardening of your leaves, which are the mites food source. Although this does work, keep in mind silica levels with human consumed plants. If you are using silica as a tool to fight Mites then a decent flush of the plant should be carried out before harvest.
If you choose this solution then diluted or organic mite spray is recommended. If spray is not organic then synthetic toxins are consumed by your plant. Once again a decent flush to be carried out of plant before harvest.