Hi there! I’m desperately hoping someone can help me with my poor suffering Meyer lemon!

I’ve had this young tree for about 15 months, and periodically it sprouts a batch of brown spots out of nowhere. They all show up at once, a bunch of leaves are murdered and then the tree seems fine for a few more months. This has happened three or four times; it seems to appear a few weeks after each bloom and I thought maybe fertilizer could be a culprit but I’ve only fertilized 3 times and not always in sync with the bloom.

I’m in Zone 10a, in Oakland, California. It’s a Mediterranean climate, rarely above 80 degrees and the coldest nights barely dip below 40. There are thriving mature Meyers all over my neighborhood.

My tree is on a southwest facing balcony, and gets plenty of sun and a regular breeze.

We’re under another balcony which provides rain shelter but means the tree is also not exposed to a ton of rainwater.

We have soft water here in Oakland but about six months ago I switched to distilled water in an attempt to correct this problem. I’ve also tried copper fungicide (weekly for a couple of months per the advice of the website where I bought the tree) but that seems to have had no effect.

I water when the moisture meter is below 4 and give it at least a gallon of water, until water drains out the bottom but I fear I should actually be giving this plant many gallons and flushing the soil more at each watering.

I potted this in citrus/cactus soil and I drilled extra drain holes but I also think maybe the soil is staying too wet at the bottom (even though the top is bone dry.)

The first time this happened I thought maybe it was sun scald but it’s just not very hot out; the spots appeared this time after a long stretch of temps in the 60s, maybe a day or two in the 70s.

I THINK maybe this is salt damage, due to soil not draining enough/residual fertilizer/old tap water deposits. Do you think I am right about this?

My plan is to take out the tree, gently replace the soil, flush the roots and trim any rotten roots if I see them, and return it to this pot. I’m thinking of using a mix of vermiculite, organic cactus mix soil, and worm castings, then to continue fertilizing with worm castings instead of commercial fertilizer. Is this a good idea or could I be missing something? ‘

I’ve attached an image of the tree blooming about six weeks ago, and browning now (that probably started about a week ago). And I’ve attached some close-up images of the leaves. (I have a few leaf-miner marks but that seemed to be minimal, just a handful of leaves.)

I would be grateful for anyone’s advice on how to stop this browning from hurting my beloved tree! Thank you so much!!!