Once you are sure you have eradicated the mites from your tree, begin providing more moisture to it everyday, but don't increase the watering to the roots. If you can maintain the temps in your garage above freezing it might be a better environment for your lemon tree than inside the house. It should begin to put on new leaves within a few weeks or so.

Another thing you may wish to look at is the pot your lemon is in. Have you repotted it since you bought it? If not you may have a pot bound root system that cannot absorb water or nutrients. If you need to repot, use a good mix that includes some grit, like a cactus mix and feed it with plant food designed for citrus, like citrus tone. Cheryl

You said something in your comments that has worked wonders for me..KEEPING IT COOLER..
I havn't even turned the heat on yet, for now...Thank God.

As far as the humidity. I always had an issue with mites even in the most humid conditions, with a fan going. There are mites that LOVE humdity, don't mind it..I have not gone a year yet without mites in the most humid enviroment.. Not even the local nurseries are exempt...lol

A hose off in weather above freezing is good through the winter, and in door showers definatly helps to avoid them. The tree should be ok, if the roots are ok...Check the roots..;-)

Also as for mine I have downstairs in the living room, with the heat on. No mites yet.. I have heard, fertilizing your plants with Pro-tek, a silaca base product will toughen up plant tissue, especially new growth, and can help your plants to resist drought stress conditions and help be pest rsistant! Try it. Seems to be working thus far.

Make sure you keep them as healthy as possible to resist pest infestation which will your plants withstand an onslaught of pests.

P.s....Cheryl, I just wanted to say it's great to have you here helping us all out...:-)

to get rid of the mites I had. I just mixed some dish soap in a spray bottle. make sure to get the under side of the leaf too. A large aquarium in the same room as my tree helps for moisture. I'm sure the tree appreciates the fish water also.

wonder what the N-P-K is on tank water..
oh how i hate mites