Low tick rate (tps) problem

I'm working on a mod that has trees that render using recursion (not update ticks).  Once a slice of the tree is rendered it calls the same function to render the next slice of the tree until the entire tree is formed. The tree is up to 200 blocks high with lots of branches.  The function is called from the structure element. In the game, the trees take a few seconds to render before all rendering simultaneously.  The problem is that the tick rate goes way down. If I reload a part of the world where the trees have already been rendered and saved, the tick rate is fine.  It's when I go into a region that has not been rendered that the slow tick rate problem arises.  Any ideas on how to approach fixing this?