Unexpected color variation on lilac tree
Thank you for your question. Since many lilacs are grafted onto rootstocks, I suspect that your purple scion was grafted onto a white rootstock, and thar the rootstock has managed to put out a sucker (from the root), that has matured into a plant. You can check this by following the white plant downward to see its base. You can also compare the leaves to look for subtle differences. Here is an article on these plants: http://chemung.cce.cornell.edu/resources/lilacs Good luck!