"I worry that I killed the tree with repotting or over-watering." That would be my concern as well. It looks over-potted and over-watered.

I'd remove the newest soil, set the old root mass on a stack of newspapers, old towels, paper bags ......., to 'pull' excess water from the root mass, then return it to the pot it came in, for now. The next step would be to get control of your watering habits by monitoring moisture levels with a "tell", while you plan to repot the tree into an appropriate medium (one you can water correctly w/o the tree paying a tax on vitality due to extended periods of soil saturation) and start a nutritional supplementation program using an appropriate fertilizer.

Al

Thanks a bunch Al, i appreciate it. How often would you recommend watering under the new cadence? Ive been doing every 3 days but have no sense for what "damp" vs "moist" soil is.... I'll stack on some newspapers and wont water it for a week or so. Does over-potted mean i need to find a smaller pot for it, or the opposite? Thanks again for your help

You will water more in a clay pot as opposed to plastic, but 1/2 gal every other day for a plant indoors sounds like a lot.

A wooden skewer is one way to check soil moisture. A finger is another way.

Is it the moisture control MG mix? That is particularly not a good mix for citrus.

Plain potting soil is fine for citrus, and even better is mixing in more perlite so that it drains faster.

But they are heavy feeders, so once you dial in the proper watering, you need a fertilizer with micros (such as DynaGro)

Hey Hibiscus. Yep, its the MG moisture control potting mix. Honestly its the only thing Target had and i cant go elsewhere due to the non-essential business shutdowns. I'll look to order some perlite and remove some of the potting mix. I dug my finger 2 inches into the soil near the base of the plant and it was cold but no water was on my finger when i pulled it back out. So I thought i was ok.

I am not sure how bad it really is, but the general opinion is that the water crystals are the issue. You can end up with root rot because it does not dry out enough between watering. The clay pot may help combat that.

Home Depot and Lowes should also be open.

Watching for wilted leaves can be a way to assess a citrus' water needs. They can actually tolerate a slight wilt unless they are in flower. In your case my guess is that those lower leaves are now actually no longer functional, so when you water they will not respond by lifting up, so don't judge by those.

It's essential for growers to understand that an excess of water in the rootzone causes the same loss of turgidity (wilt) that a water deficit causes. With that in mind, wilt is not necessarily a signal the plant needs more water. It can just as easily be a signal the plant is dying of thirst in a sea of plenty. It takes energy to move water throughout the plant. A scarcity of air in the root zone, whether due to soil compaction, poor gas exchange, or excessive amounts of water, deprives plants of oxygen required to 'burn' the food which provides the energy that drives root function.

Al

Should i consider trimming those bottom leaves off as i dry out the soil, to ensure that moisture more efficiently reaches the top?

There is an area where the leaf attaches to the branch called an abscission zone. In order to keep an abscission LAYER from forming, a certain amount of a specific hormone (auxin) must flow through the abscission zone. When the amount of auxin is insufficient, an abscission layer forms, effectively walling off the leaf from the rest of the plant. Until this layer forms, the plant will be "salvaging" mobile nutrients and biocompounds for use elsewhere in the plant, so it's better (for the plant) to avoid removing the leaves until they're completely dehydrated and crispy. Also, removing lower foliage isn't necessary to ensure the top of the plant is adequately hydrated. In apically dominant plants, the top of the tree and ends of branches oriented more toward a vertical position will be more powerful energy sinks than other branches low on the tree. The tree's energy comes from the food it makes (sugar) and is delivered in the nutrient stream, the strongest energy sinks receive the lion's share of the energy allotment. The only way to effectively prevent this from occurring is by reducing the foliage mass of the stronger energy sinks, which will force redirection of energy to the weaker/lower branches. More accomplished bonsai practitioners keep a tight rein on their trees' energy flow, making sure the right branches grow and thicken properly while restraining the top to prevent over-thickening in areas that would normally display twiggy growth. If the lowest branches aren't the thickest and upper branches thinnest, it jars the eye. Even if the viewer can't place exactly what's wrong, viewers will be left feeling something is out of place or doesn't look right when there are heavy branches high on the tree and thinner branches below ........ but I'm starting to stray here ...... .

Al

Leave the lower leaves until they drop

Hey all. I repotted, water 1/4 gallon every 3 days or so, and added a grow light for a few hours a day, due to my window direction. Now, the bottom leaves that were previously broken have since fallen off, but the top leaves are drooping slightly and some are curling up (which i thought was a symptom of overwatering?) I have not done anything with nutrients since getting the tree, as i was trying to stabilize the watering regiment. Any thoughts? Updated picture below

The best thing to do is to check how wet the root zone is. We've established your mix is not a fast draining mix. Al explained why frequent shallow waterings are detrimental. You've kept the same frequency but lowered the amount. I would suspect that is not helping because it's still not allowing the root zone to dry and instead you risk building up salt levels in your soil (when water evaporates it leaves behind salts, which need to be flushed or they make it harder for your roots to breathe and take in water). So the question is are you over- or under-watering. Forget what you think should be normal. You have to respond to the actual state of your potting mix. That's all that matters.

Al's suggestion of using a dowel to assess moisture at the root zone level is on point. If you're not sure about that, carefully lifting your tree and looking at the soil around the root ball can be very informative. I once had a tree that I potted in a fast-draining mix after buying it; I was perplexed when it showed signs of overwatering. I pulled it out and discovered the root ball (which I left intact from the nursery container it came in) was a soaking, suffocating mess of broken down mix. Moral of the story, I learned a lot about the status of my soil around the root zone by looking at it.

Another clue is how the tree responds when you water. If my trees are happier when I don't water and I get more yellow leaves and drooping when I do water, that tells me I am watering too much. With practice, you will be better at knowing when to water.

You have to choose the correct potting mix. The problem is the wetting agent. It has a chemical which holds 30% more moisture. Look for a potting mix with a maximum moisture content around 50% and one without a wetting agent.

Media treated with a wetting agent hold less water at container capacity than untreated media.

Also, consider carefully before you buy into the idea water absorbing polymer 'crystals'. When media are moist, they serve no purpose. As a medium dries down, the crystals can hold what would otherwise be available water so tightly it's unavailable to the plant.

Al

Direct from Miracle-Gro the potting soil you are using "Absorbs up to 33% more water than basic potting soil (vs. potting soil that does not contain sphagnum peat moss, coir and wetting agent)".

That being said in two days a wetting agent is not going to have catastrophic effects. Your lemon tree is in shock from moving from the greenhouse to indoors. The plant can't uptake enough water to compensate for less humidity. Water more and move it back from the window. Buy a $20 infrared thermometer on Amazon and check the actual temperature of the leaves.

If you just fertilized when reporting that could also be the issue.

Tap water is not great. If water is cold that can shock the plant. Ideally water should be the same temperature as soil or warmer. I use reverse osmosis indoors and I use tap water outside but let it sit for a few days for chlorine to evaporate. Outdoors I have a garden house with heated water 90F for misting plant and knocking bugs off.

Hello everyone! Just a quick update, my tree flowered! I dont know what this will mean in terms of lemons but it has about 15 blooms so far. About 5 of them have opened and then apparently turned yellow and died? But the newest look healthy. I havent changed anything except putting egg shells in the soil. Excited to see what happens next or if there is any particular advice for this next phase to ensure the tree continues to live! I took a Qtip in between the male and female plants to pollinate them.... before half of them died. Ha

Pic 2 of full tree

Hi HU, citrus blooms can be triggered by stress. After a period of stress "drought" they may bloom. How many times per year depends on the cultivar of citrus. The larger the size of the fruit of the cultivar the fewer number of blooms. Some limes and lemons, for example, can produce up to four times a year, while the citrus blooming season for those big navel oranges is only once in the spring. There is a plethora amount of hack videos on the web about how to pollinate citrus for a bumper crop. The videographers all state this a necessity indoors. Its all BS. I tried it once with the tiniest artist paintbrush I could find and it knocked off 80% of everything I touched. Most citrus are self pollinating. I have a bummer crop of sweet oranges from last November that all bloomed indoors with no help from me to pollinate. Two of my trees have about 16 full size sweet oranges between them. 3'rd tree is the same cultivar and dropped all its fruit. My 4'th orange tree is a different cultivar and did not bloom last year. I harvested fruit last fall and again they bloomed indoors the year before and were never hand pollinated.

https://www.walterreeves.com/food-gardening/pollination-requirement-and-seeds-in-citrus/

A very high percentage of blooms and fruit will fall off naturally. Say 95%. Indoors you have a couple extra obstacles to deal with. Indoors you have low humidity and no natural breeze to cool the leaves. You have high leaf temperature and cold roots from radiant heat near a window. Spend 20$ and get an infrared thermometer to check leaf temperature. When leaf temperature is about 30F hotter than root temperature you will start to see more leaf drop. If leaves get too hot pull it back a few more inches from glass. Get a misting bottle and keep the blooms moist. Warm water to 90F. Cold tap water is a real shock.