I would be more aggressive with your spider mite treatment, igrowlemon. Just wiping them off is not helping it appears. I would be sure to spray very well with a hard blast of water outside, then treat the underside of your leaves (take care to get ALL the undersides of ALL leaves) with Neem oil. Keep your tree outside as you can, and after treating with Neem, keep it in the shade for a day or two, then in the sun as much as possible, bringing back inside if your temps threaten to drop below 40. It may take a couple of treatments to get rid of all the spider mites. Look for spider mites on other indoor plants as well.

Patty S.

Most likely edema, caused by overwatering in cool weather.

A word of caution, since it is a Meyer; when you move it outside, put it in full shade for 2 weeks; then 2 weeks in partial sun; then to full sun. Reverse the process in the Fall and you should avoid the heartbreaking leaf drop that so many Meyer container growers experience.

Yes! To go along with Patty, I was going to say it looks like that 'Dracena' in the back round has them too.

Those leaves should not look tired like that.

Great advice given you here. Once you get it outside, wash all the leaves off and gradually introduce to sunlight as John says.
I live in Ma. too and I pray it warms and stays that way! Mine are about to jump throught teh window pain.

Mike

I keep the tree on a south facing side- with a wall of floor/ceiling windows. so, it gets full sun everyday inside anyway. Do you think that bringing it out onto a south-facing deck would be any different, come springtime? I took it out today in full sun for several hours. Do I still need to 'reintroduce' sunlight to a plant that lives on the southern side of my house?

Is Neem oil known to be effective? I wiped all underside (and tops) of leaves, and despite this, still see tons of spider mite eggs.
IS the general consensus that the leaf drop is due to the mites? I think my ivy has mites as well.

"full sun" window is no match for outside sun. The Meyer is quite sensitive to light changes and will drop most or all of its leaves in response. Full shade outside is more or less equal to "full sun" inside.... Don't fight the problem, there are lots of folks here who have had the bad experiences.... try to learn from them, instead of learning from your own experiences which are often painful and also expensive. The neem oil, if applied carefully and again in 10 days, should solve most of the problems. Note that spider mites and other mites like dry/dirty conditions; when you put the tree outside, one of the best remedies is just to give the plant a good wash every week or so.

John is right about being outside - it will help to get rid of the spider mites as their natural predators live outside. Yes, your leave spots and dropping is due to spider mites, they can wreak terrible havoc on certain plants. So, spray with a hard stream of water to knock off as many as you can, treat with Neem very thoroughly, and follow John's advice about slowly. I think at your higher latitude, you can probably move into the sun a little faster than 2 weeks, but do it gradually. A few hours a day at a time, increasing a few more each day. Morning sun is less intense than afternoon sun. And Mike has a sharp eye - do treat all your indoor plants as they most likely all are infected to some degree and they'll continue to reinfect your little Meyer lemon if you bring it back inside.

Patty S.