In October 2016, U Of M Disease Clinic diagnosed Rhizoctonia root rot for 2 of my lilacs. Last year and this year there were no symptoms. However the white lilac , which was planted 6 years ago, bloomed for the first time last year. The lavender lilac is a slip from my mom's original lilac in Kanabec County. Planted 5 years ago. It was very small/...now about twice size as when planted. Seems slow. No blooms yet. It is 34 inches tall and crown is 15 inches. We do have a low back yard, so things stay moist longer than in front. Anything I can do to get lavender lilac to grow more? My understanding was no fertilizing was necessary. Since it is from our mom's property it is kinda special. Thank you Melanie Carlson email: firstname.lastname@example.org
Hennepin County Minnesota lilac
It is good that you had a proper diagnosis of the root rot. So you are wondering about the lack of blooms on your mom's lilac. There can be a few causes but it can also take many years for them to bloom.
Could be poorly drained soil or lack of enough sun. If you don't see any pest or health problems and have not pruned it then I would wait another year. No fertilizer necessary. Here are good links.
Thank you for your prompt response. I love this service!!!