A "NO MORE SPIDER MITES OLD SKOOL FORMULA" I have been using for several years is as follows:
(finished product will be 64 ounces, for more adjust accordingly)
* 4-5 Habanero peppers per 1/2 gallon finished product desired.
* 3-4 grams tobacco (preferred natural, roll your own chemical free tobacco)
* 2 garlic cloves
Crush and make as small a pieces as possible each of the above and put into SEPARATE ready boiled water (approximately 16 ounces of water in each)that is turned off and steep for 20-30 minutes until cool. DO NOT BOIL THE INGREDIENTS AT ALL!!! THESE MUST BE DONE IN THREE SEPARATE SAUCEPANS WHILE STEEPING. Once cooled, blend the three above ingredients into your 64 ounce container, and add clean, filtered water to make up the total of 64 ounces.You will have lost some to evaporation. For some unknown reason, the three MUST be done separately, if done together, there is some funky chemical reaction while it is still hot. Once blended, add 3-4 drops of olive oil and shake to mix. Shake while using too as things settle. Spray the plants like all the other methods tell you, careful to get EVERY spot on the plant, soil/media and even the surrounding floor area. Plats love it, can spray in flower too, up to the day before harvest. Totally organic!
Like I said, I have been using this over 3 years and have no more mites. I found this after having an infestation that NOTHING worked on, until I did this. OPTIONAL Geraniums in the grow area as well as their extract, added to the above formula adds a good boost to the defenses. Also Carnation, Cinnamon and Peppermint.