Foliage falls through mesh

Hello guys,
I’m working with UE4 just for a few weeks and I have a problem. When I paint foliage with it’s tool it’s placed too low…inside the landscape (static mesh). You can see in the picture what I mean (don’t think about the graphics, it should be so “bad”). I could place it higher manually, but the plants and the trees would need different heights. Does anybody know why this happens and how I could solve this problem? In my other level it just works fine.
Thank you :slight_smile: