Kris, what type of soil is your lime potted in, and how much light will it get during winter months?

12-5-7 plus nutrients sound right. Definately, enough Nitrogen.
I'd give it one dose, the last of the year, then give it a rest until spring.
If you're tree is in complete soil-less mediums, I hope those who go that route jump in, I believe citrus are fertilized year round.

You'd add the doseage listed for indoor plants. Did you buy Osmocote? Toni

It's potted in pro-mix. Not sure if thats the best for it or not but I try to keep it on the drier side so I don't over water it. Over the winter I'll keep it in my sunroom that has a south west exposure. Once all of our leaves drop outside it gets pretty bright in here in the winter. The brand of the fertilizer is "Expert Gardener". I'm pretty sure it's just a walmart brand.

Definitely be careful with Pro-mix. It is made up mainly of sphagnum moss and retains a ton of water even after it stops dripping. This could be an issue over the winter, because container trees don't need nearly as much water when indoors.

By way of example, my trees get water about once a day when it's 85-95 F, but when they come indoors they only need water about once a week. That's how big the difference is.

Once you bring your plant indoors for the winter, it will be much, much less forgiving when it comes to water. A water meter only costs about $6 and can save your tree's life, no exaggeration.

To answer your actual question, that's probably an acceptable fertilizer, but I agree with Toni, you should be thinking about giving your plant(s) their last fertilization of the year right about now.

I know that promix holds water a lot and I thought that might be a problem. I have a water meter on hand. If it registers any moisture does that mean I should not water at all until it is completely dry?

That is the trick of watering..Knowing just when to water..For some it can take years learning like me, for some it is a gift.

I have killed a many citrus with moisture meters..Never let the meter register completely dry..The line between moist and ry is good..You should also flush your soil out with fresh water, preferably fresh rain or bottled water to rid the salt build up in that type mix..Salt levels can also throw your moisture readings off..

I have found these thing never reliable for me..I use wooden dowels and only water when the stick feels dry..

If you find your mix taking a week or longer to dry out, you might want to consider using a better mix than wait till spring to see what happens..Just my take..:-)

In that type mix, I agree with Toni and Displacer, or at least be stingy with it if you find your tree starts to loose true color not due to over watering and root rot...

Mike

I was thinking that maybe I should try and get through this winter with the promix and then repot it in the spring. I'm also wondering if I should repot it in a smaller pot. Have you had any experience with the miracle gro soil for citrus?

I've never used the Miracle Gro mix because it's not very good for citrus. IIRC (and if I'm not thinking of something else) it is a very heavy, dense potting mix that tries to compensate for its waterlogging nature by containing a huge amount of sand and perlite. Sand and perlite can't fix what's wrong with Miracle Gro mixes.

With my first citrus tree, I did all the wrong things (I didn't use Pro-mix but what I did use was very very similar) and it still lived for almost three years. When it did die it was because of spider mites and not because I'd messed up the soil. So leaving it in the Pro-mix until spring is not a death sentence, as long as you are careful about watering, and then in the spring if you want you can put it into something more carefree.

If your moisture meter is anything like mine, you don't want it to get to "dry." Mine has 4 numbers, with 1 being dry and 4 being wet, and I like to get it to slightly under halfway toward dry before watering (in other words, about a third of the way down into "2").

What is critical about using a moisture meter is to ensure that the tip is in the soil that actually touches the roots - don't just slide it down along the edge of the pot where you may not have many roots growing - and to =measure more than once=. Your soil may be wetter in some places than others, so jam the meter down at least twice in different spots. If you get varying readings in different spots, try to mentally average out your readings. If your readings are extremely different, you're probably not choosing your sample spots well.