Mass place trees with coliders?

Here’s my problem:
I have a tree and I added a mesh colider on it.
The problem is - when I mass place, or paint the trees in my terrain(I created a prefab of the tree with the mesh colider), I can still walk trough them.
How to paint or mass place trees with coliders on them?
Please help.

Your character/object that will collide with the trees need the component, Rigidbody to start interact with the game physics.

Once you have a object with Rigidbody interacting with another object with a collider you’re good to continue.