swimming pool caustics - trees leafs problem

Hi,

I have an outdoor scene with a swimming pool where the water generates caustics (inside the pool).

Near the swiming pool, I have trees that use opacity map and refractive set to 1.

The problem is that I only want the caustics to be calculated for the swiming pool. So I turn “generate caustics” OFF for all other objects.

The problem is that now my trees do not cast shadows properly :? (like if I didn’t enable in the material editor “affect shadows”)

Any ideas?