Hello,
I have a loquat plant that I planted from seed 3 years ago, but very recently the leaves started dying (turning brown and shriveling up). My plant is forked at the very base, so it has two skinny trunks (each about 3 feet tall) with large leaves growing directly off from both trunks.
This plant has always been in a container. I have re-potted it in larger planters twice now - it started out in a little terracotta pot. When it outgrew that, I moved it to a 10" diameter glazed ceramic pot for 2 years. I re-potted it in a large resin planter (18" diameter, 16" deep, with two 1/2" drainage holes in the bottom) about 2 months ago. It had been doing really well in this new, bigger container. It grew a few inches taller and some small branches started growing out at the top for the first time, so I was really happy to see it healthy and growing.
Then 2-3 weeks ago, some of the leaves started getting brown patches on them. I have a few other smaller loquat plants in containers that have had brown patches before, but only affecting 1 or 2 leaves at a time. Those brown patches hadn't seemed to affect the overall health of the smaller plants, so I wasn't concerned about my big plant at first. I removed several browning leaves a week ago, and decided to water it less frequently because I thought I might be overwatering it. I live in Los Angeles - it's been dry with temperatures in the 70s-80s, so I had been watering it every 2-3 days. We just had a heat wave with temperatures ranging from 90-100 for 4 days, and my 3-year-old loquat's condition went downhill quite a bit faster during this time. Almost all leaves are affected now, so I am very concerned. I have put a lot of time and care into it, so I want to save it.
Today, I inspected the trunks and leaves for pest activity and did not see any insects, scale, or white powdery mildew. I dug up the plant, so I could look at the roots. The larger roots are mostly cream-colored, but there are many thin, dark brown roots along the bottom. I hadn't watered the plant in a couple days, but the soil was still moist in the lower 2/3 of the planter. I use a Miracle Gro potting soil, but I mix in used coffee grounds to help the soil go a little further and because worms love the coffee grounds. I figured making the soil amenable to worms would be beneficial because they would help fertilize the plant. While digging the plant out, I did notice a few worms in the container (~5 or 6).
I know this is a long post, but I wanted to give as much context as possible. I am really an amateur gardener, so I would appreciate any information/advice you can give me! Thank you in advance!
Lindsay