Hello,I have a ficus bonsai that has an unusual problem with its leaves. We've had the bonsai for about 10 years and haven't seen this before. On new growth leaves, there is odd discoloration. This is more severe on lower branches. We had not been giving fertilizer because its winder, but we gave a small amount once we noticed the leaves. We also dosed with eddha iron chelate a few weeks ago, but no change. The fertilizer we use is biogold slow release 5.5/6.5/3.5.Attached are a few photos. Thanks!

I cannot tell you what the problem is or how to solve it. But just want to point out that theese leafs will always be yellow until they fall Any recovery will be seen in new leafs only. Since it is winter now, the tree is not growing much. Any recovery will not be seen until spring.

Iron deficiency is first seen in new leafs, since your problem is most severe on old leafs you can rule out Iron deficiency.

Thanks for your reply. The issue seems to be primarily on new growth leaves. We'll continue to monitor it.

My bad. Discoloration on new leafs can indeed be due to Iron deficiency. But it is not sure that adding more Iron to the tree helps in that case. The most common cause of an iron deficiency is high soil pH (but only on trees that are naturally adapted to low ph like ficus). There may be other factors at play, including: Excess of manganese, copper or zinc, which will impact the iron update by trees.

If Iron deficiency is suspected in ficus the first task that should be done is sheck the water. If you are using tap water you can get a water analyse from your local water plant. If you are in an area without severe polution, the best water to give your trees is most likelly rain water.

Have you checked thurougly for pests? That is also a possibility.

My first thought looking at the leaves was pest. Possibly red spider mite.

Thanks, I've continued to monitor and haven't noticed any mites. I tried to identify them by putting a white sheet of paper under the tree and then looked at the specs that fell off under a magnifying glass. I only found little pieces of bark. I also looked under the leaves with a flashlight and didn't see anything unusual.

Now a number of leaves have turned yellow and have fallen off. I've uploaded some updated pictures. You can see the older leaves that have the strange venation and the newer light green leaves (as well as a few yellow ones that haven't fallen off yet).

The water seems like a possible culprit. We run the water we give our bonsai through a brita. We were in New Orleans for the last three years and are now in upstate New York (as of August) so I'm wondering if the water (or maybe just winter?) could be the culprit. It is definitely less happy than it was in New Orleans. It was growing aerial roots, but that stopped when we got to New York. We do have a plant light (2x F20 T12 24 inch bulbs) for it that we have on for 13 hours a day. Any thoughts are welcome!

Ficus houseplants are tough, having a light on that long is not a good idea, they do not need that amount, if any extra. It could be the cause or it could be the plant is losing some leaves naturally. I doubt the water is a problem

Brita....Isn't that the kind of filtration that runs troue salt pellets? Maybe your problem is salt poisoning?

Less areal roots suggests that your new home is lower in humidity. Is your new home in a colder climate and you are heating more? Where I live in Sweden all ficus lose a lot of leafs in winter. Lack of light and low humidity beeing the most important reasons. However, I haven't noticed that severe yellowing.

I missed the bit about Brita. If it has salt then that will be a problem. What's wrong with mains water?

I read up on brita. That is a brand for water treatment products. They have activated carbon solution as well as ion exchange products. The first one is ok, the second one not.