25 years ago in inland northern California I planted half a dozen Tulipa saxatilis var. Lilac Wonder beneath a small Hawthorne tree. As the tree has grown, so have the tulips, which now surround the tree after squeezing out some commercial tulips. The tulips and the surrounding lawn are watered in the summer. Neither have been fertilized (except where passing dogs poop)in 25 years and are thriving.