What to Look For
Lilacs can be challenging to identify, which is why breeders created color and flower classifications. Though helpful, these systems are imperfect. Many lilacs change color throughout their life cycle, sometimes even changing daily as flowers open.
Lilacs often appear two toned when one side of the petal shows a deeper pigmentation than the other. Variations in the environment such as soil chemistry can also change flower hues. Cool, damp weather allows the flowers to retain their initial, intense color for longer, while hot sun fades color. A lilac’s scent is similarly altered by its environment. Flower buds form during the summer before their spring bloom, so last year’s weather can impact this year’s flower, altering the intensity of the fragrance.
When buying lilacs for your own garden, note that because of these factors the plants may be mislabeled. NYBG’s LuEsther T. Mertz Library has resources that can be helpful in making proper identification of lilacs. Listed below are some other resources that can help:
The International Lilac Society’s list of sources for online or mail-order lilacs
If you are looking for a specific cultivar:
The University of Minnesota’s Plant Information Online
Royal Horticultural Society’s Plant Finder