My Chinese Elm has been doing great! Old leaves fell off and new ones growing. I have a plant with a bunch of healthy leaves. But when I went to water the soil the other day, I saw a spider mite. I was wondering if they stay for the winter. Thanks!

If it is still growing I assume you keep it indoors. Then why would you think spider mites care about winter outside if they are inside?

It should of course be outside, and therefore the spider mites will not be a problem.

"I saw a spider mite"
Hm.. I doubt it. These critters are really the size of a grain of salt, move slowly. The main way to detect them is through silvery webbing that starts to cover branches and leaves. The individual animal is virtually impossible to spot. You probably have seen another animal.

As for your question. Spider mites populations are domant/surviving winter through eggs