Multiple Trees in one hex Z sort prob.

Ok it has been asked in different ways over and over again but still no clear solution has come up that works for me in maya.

This is what i want to do:

I want to create a single DTS that contains the folowing:

A ground mesh and 3 trees.

I can create thins and having ONE tree work perfectly But all other trees are rendered UNDER this tree if i rotate the view. I cant get the hiearchy to work in any way.

Need a solution. I have read all the posts about Z sorting and SORT. Just doesnt work out.

I used a differnt tech for doing this and it worked but now i need to have all the trees in the same DTS with the ground.