Ask Ed: Grow Questions and Answers – Mite Infestation

CANNABIS CULTURE – Ganja Guru Ed Rosenthal on how to eliminate mite infestations.

Question: We have been growing for more than five years and we constantly have a problem with spider mites. Sometimes we use a homemade pesticide we make from dish soap, tobacco, alcohol and water. This knocks them out for one and a half to two months but then they return. How do they get into our garden? How can we protect the plants?

P.O., Ottawa, Ontario

Ed Rosenthal: There are a couple possible explanations for your recurrence of mites. One is that they have re-colonized your garden from outside and the other is that your knock-down spray, while highly effective, didn’t get every last mite. Just one fetid female can restart the cycle.

The mite road to your garden from outside has several arteries: they can hitchhike a ride on shoes, clothing, hair or garden tools. They can ride in on the air stream or thrill-slide through an unfiltered vent system to a veritable sea of green. They can also sail through an open window or door. The easiest is garden-to-garden transfer via plant or cutting. Nothing could be more convenient; they can continue to eat while traveling.

If your garden gets re-infested during the winter when there are no active mites outdoors, and you haven’t carried a mite in after visiting another garden, you should assume that you did not totally eradicate the mites or their eggs and the survivors repopulated the green room. Mite eggs are somewhat impervious to insecticides. If this is the case, the next time you spray, instead of a single treatment, use the pesticide three times, three to four days apart. That way any survivors or newborns will be killed.

Send your grow questions to Ed Rosenthal at [email protected].