A Londoner in need of help, please. I have a 20 year old Benjamina Ficus bonsai, which was purchased a year ago. After a few weeks it adapted from the nursery to the home environment and everything was good. It was growing very well and lots of leaves. On Feb 4th I took it back to the nursery, upon advise from the seller the previous year, to assess whether it was pot-bound. So, it was last checked up on in February by this reputable nursery and it was decided that it was not pot-bound so no need to disturb the tree. The seller also commented how very healthy it was.
In March, as the lighter days were coming, the tree started producing huge amounts of shoots and leaves and was developing for about a month or so. Every single branch was coming with a multitude of shoots. Then suddenly around mid-April, the new, light-green leaves started curling up, going brown and falling (first affecting the left side), whilst the old, dark green more leathery leaves were staying. When it recovered somewhat, it affected the right side the exact same way. It is now June, and the right side is virtually bare, but is covered in new shoots. Also, the new leaves are no longer falling to any great extent on the side that started recovering, but the old leathery leaves (specifically only them) are going yellow (exactly the same was as trees do when preparing for winter) and slowly falling off.
The tree stands in a bay window to get as much light as possible, but there are sheer blinds installed to protect it from the most powerful direct sunlight, also because we had the sunniest spring and hottest May on record. I was checking the soil and humidity as I've done before, so I can't think I have over/under watered. It gets its occasional fertiliser too.
This is so bizarre and I am at a loss. It has so many shoots and keeps developing them, but no leaves.
Thanks for any advice.