I am at my wits end over this Meyer Lemon tree, which is sentimental to me. It simply refuses to grow new leaves, and as you can see, it looks quite sad. Six leaves left. Some background: My fiance bought me this tree for my birthday last year, and it managed fine through the summer (though it lost some leaves) and then I moved it inside for winter. The spot I put it in didn't get quite enough light; it developed the large leaves you see here, but a lower branch died. This spring I moved it to a somewhat sunnier spot (all our light is north facing, but it's in a bigger window and not a corner) and even bought a full-spectrum bulb for a desk lamp near it. Once it was reliably sixty degrees (F) at night, I moved it to our (still north-facing, recessed) balcony (I transitioned it by leaving it outside for the warmest part of the day for a few hours every day before leaving it outside full time). Over this period, it's consistently lost leaves. Not dramatically or all at once; just one a week. They get yellow veins down the middle, and then drop. I water thoroughly once a week, being careful to empty the container its in afterward so the roots don't soak, and I've fertilized with a citrus fertilizer two or three times in line with the instructions. I recently order a moisture meter and a nitrogen soil test, but they haven't arrived yet. What more can I do for this plant? It's flowered prodigiously (2-3 times) over the spring, but stubbornly refuses to grow new leaves. I've been picking off the tiny baby lemons so it will conserve energy, but it remains naked and ungrateful. I'm on the verge of calling it a "lemon" and buying a new one. (Please excuse that terrible pun.) Do you think it can be salvaged? If not, should I buy a new Meyer Lemon, or is my north-facing light just never going to work? I live in Washington, DC (cold but mild winters, but hot balmy summers). Thank you so much for any advice.
The tree is probably slowly starving to death from insufficient light in its north facing location and the decline will continue as long as the problem is not addressed. The yellowing leaves are ones that are old and in the process of being shed. I suspect it's impossible to grow citrus in this location without investing in significant artificial lighting. Rather than trying again with a new tree, perhaps you can leave the tree with a neighbor, one with a southern exposure, where it can rejuvenate before being brought back for another go.
