I have them on a holly bush.

I bet they like it there.

Maybe there is some focus on one plant species or another but, I wonder. This dahlia was growing within 5 feet of a small pine. It is exactly the same location where a dahlia died after spider mites swarmed it, last year.

Those 2 deaths are the first-ever in the dahlia gardens that I can attribute to the mites. However, how many mite-weakened plants produced roots which could no survive winter storage? Death several months down the road may have had to do with the nasty situation through the growing season.

Steve

I am still hosing down the plants prior to spraying them. In the rose greenhouse where I worked, this was common practice. We claimed that it killed more mites than the spray.

There are a number of "miticides." I seem to be stuck within the homeowner's limits. Anyway, farm miticides are sold in bulk and are expensive. I don't know of many choices. If you do, let me know.

First of all, I know that various horticultural oils and soaps kill spider mites. Problem is that with a few hundred dahlias, I can't do a good job with a contact spray. So, I use systemic.

The last two years, I have given them a one/two punch. I spray alternatively with Bayer 3-in-1 and Bonide Systemic. I wish I'd started earlier for this plant. It seems to work.

Cooler weather helps and I've learned that watering more often benefits the dahlias and hinders the mites. They will kinda fade away with the cool rains of late summer ... whenever they might show up. A record high again today, probably with about 12% humidity -- the mites love it!

Steve

I get by with one spray of Bonide. I never could get anything else to do much. With egg plant, it *seemed' as if dormant oil helped, but I can't confirm that.