My indoor lemon tree was doing just fine and had a beautiful bout of growth, some branches developing huge leaves and up to 10in in new growth. I've had it for about a year.
However, several leaves (~10) started yellowing and falling off. I'm attaching some pictures below of what the fallen leaves look like.
- I don't think I over-watered it. I always wait until the soil is very dry and never water more than once a week, more like every 10 or 15 days. The water drains out nicely and fills the saucer.
- I don't think I over-fertilized it. I gave it some general-purpose fertilizer 4 and 6 weeks ago respectively (new growth was picking up) and haven't fertilized it throughout the winter or after that.
Two topics of concern:
- cleaning underneath the pot revealed a yellow fungus spread, but it didn't seem to enter through the watering hole
- spider mites, which I've been battling with spraying soapy water on the leaves.
What are your thoughts? Does this seem like something caused by spider mites? By a fungus? Or something else I'm not thinking of?