When we bought our house about three years ago, we bought a landscaper’s dream and nightmare rolled into one. And just like it is possible to see a snail’s movement over a three year period, over these three years, we have moved the ball slightly downfield. Of course, when this past January we had to dig up our front lawn and flower bed, it set the snail back like a holding penalty.
But my wife saw opportunity, and her eye turned to edible landscaping. After a recent plant purchase, I asked her how her Mother’s Day budget was coming.
Her only reply was, “I think we are into Father’s Day with this one.”
When the plants arrived, so did a generic guide with care instructions. I enjoy reading these things, because I can always learn something new, so I leafed through the pamphlet. What I read about pruning lilacs stopped me in my tracks:
“Do not prune lilacs heavily,” read the first part.
In the photo, you can see that I had just done this very thing for a customer. So I kept reading:
“Prune at the ‘Y’ just beneath the spent bloom.”
My inclination was to think these instructions were mixing the proverbial apples and oranges, so I thought I should confirm with some online research.
When I searched “renovate lilacs,” I was comforted to find I had been nearly correct in all of my past lilac prunings. (As with all prunings, I rarely get calls for anything but renovations: “Honey, call the arborist, because I cannot find our garage anymore.”).
With overgrown lilacs, I have had success in the past by removing the oldest, tallest stems, and cutting others back to younger, shorter sprouts. (Near the base, the difference between old and young lilac sprouts is striking. Old bark is gray, and is already peeling away from the stem in thin strips, while young bark is a dark tan, well attached to the stem, and cannot be peeled away). My online research recommends removing all sprouts to the ground, except in the case of obvious grafting, in which a portion of each stem must remain above the graft so that the grafted plant can re-sprout. In the case of grafts, all ground sprouts must also regularly be removed, or the rootstock will replace the graft.
The logic of complete removal is to force the mature roots to produce new shoots, which will happen unbelievably quickly. If possible, I like my hybrid approach better, since some of the plant still remains. On the other hand, the generic guide was discussing pruning to produce not a better plant but better blooms.
Back to my house. All of our lilacs are leggy, and their blooms diminished. Now, if I could just get the courage (and permission) to bring the chainsaw home.
Joshua Arp is an ISA-certified municipal specialist, Clarks Summit’s municipal arborist and an operator of an organic lawn and landscape maintenance business. Reach him at firstname.lastname@example.org.