lilac health - Ask Extension
I have a small group of lilacs that are about 25 years old. They get good sun exposure and there is other healthy shrubbery nearby with similar sun ...
Knowledgebase
lilac health #944970
Asked September 13, 2026, 8:59 PM EDT
I have a small group of lilacs that are about 25 years old. They get good sun exposure and there is other healthy shrubbery nearby with similar sun and soil. During the last few years they seem to have acquired a look that I would describe as thin-leafed or scraggly.
Do lilacs sometimes have a life span like trees, and just wear out? I have thinned them over time by removing the thickest stems to keep them healthy but have avoided fertilizer My question is whether to try to rejuvenate with fertilizer or replace them?
Anoka County Minnesota
Expert Response
I suggest a soil test to see which if any fertilizer is needed.
https://soiltest.cfans.umn.edu/
Note the lifespan comment in this web page, 100 years.
https://www.thenews-messenger.com/story/news/local/2025/05/14/master-gardener-the-longevity-of-lilacs/<personal data hidden>/
Note other diseases may the culprit. See this web page.
https://extension.psu.edu/lilac-care
https://soiltest.cfans.umn.edu/
Note the lifespan comment in this web page, 100 years.
https://www.thenews-messenger.com/story/news/local/2025/05/14/master-gardener-the-longevity-of-lilacs/<personal data hidden>/
Note other diseases may the culprit. See this web page.
https://extension.psu.edu/lilac-care
