Lilac Growing Issue



Hello : I live in Toronto (Victoria Park/Sheppard ) . I believe I have loam sand in this part of my yard. The pictures I have submitted are from a small lilac tree that is over 10 years old. This tree was located very close to another,larger lilac tree until this year. The larger tree has always grown very quickly and is doing well.This smaller tree seemed to struggle and grow very slowly compared to the larger one ( It had been putting out a few blooms over the past few years,but always stayed small). Both were located in the south-west part of the backyard and received the same amount of sun and rain. In the first week of May , we decided to move this tree to a sunnier,open location.When carefully digging around the tree, we found about half of the roots to be over a large concrete slab underground. These pictures were taken May 23 . The tree began to leaf this year, but now seems to be “frozen” and the leaves are not getting any larger.
I watered it thoroughly / daily after transplanting. Any thoughts or suggestions would be very much appreciated.


Thank you for contacting the Toronto Master Gardeners with your question regarding your recent Lilac transplant.

It is not too surprising from the transplant trauma you described that the shrub is shocked.  It would be prudent to take out your pruners and remove as much weak wood as possible, leaving only the healthiest branches that have most leaves. The goal is to get the most energy going to the viable branches, but try not to be excessive.

So carefully identify weaker branches and cut them back to a node where there is a branch with better leaves or even a healthy looking bud. If you see larger branches that are failing then I would lop them off as well. If you see energetic suckers, leave a 2 or 3 select suckers, as they will form the next generation of mature stems.

Generally lilacs do not require fertilizer, but in this case you can apply a balanced fertilizer (20-20-20) to help it along.  Also ensure that there is good drainage and they do not like grass right at their feet.

Hopefully the lilac will become established this year and you will enjoy it for years to come.