Hello, I have 2 bonsai trees, chinese elm and chinese plum and I've putted them on the window where there is sunlight in the morning and shadow in the afternoon. I've waterized them approxemetly every two or three days but the leafs started to fall off and I don't know why. Can anyone please help me?

Watering on routine is wrong. Water only when soil is enough dry on top but not extremely dry.

Pictures of the branches with leaves and a shot of the trunk with soil would help us. Just make sure the photos are in focus.

Spacewood you can't assume it's watering. It could be pest or disease or root bound... that's why we need pictures. I know you are trying to help but we need to rule out everything.

Here are the pictures.

Bonsai Bender wrote: Spacewood you can't assume it's watering. It could be pest or disease or root bound... that's why we need pictures. I know you are trying to help but we need to rule out everything.

Not assuming anything, Bender. Just saying watering on routine is wrong, as many people know already that here.

Aurorabembic
Are the leaves dry, crunchy feeling, but still green in color right before they fall off?
How often do you fertilize?
How long have you had these, and how long have they been in those pots?

yes they are still green when they fall off. I didn't fertilized them because I got them last week so I don't know how long have they been in those pots.

Since the leaves are green I do not believe you have a watering issue. You didn't mention if they were crunchy aka dried. If you are keeping them indoors they need humidity. Keeping a tray filled with acid... I meant water will help raise the humidity around the tree. Don't place the pots directly in the tray (they don't like soaking) have them sit on something to be just above the water.
I would go ahead and give them some liquid fertilizer. After doing both of those give it 5-7 days. If it springs back to life give it some slow release fertilizer. If it slowly improves then they are probably root bound. (post back if it is this and we will talk more)