JennMarie
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Total rehab or some TLC?

Hi!
We moved into a house 3 years ago but haven't been able to give the outside any attention until now. I'm learning about lilac care but because the trees have been neglected for some time now they are in bad condition. Should I do a total rehab and cut them down to the stump? This is something I heard in a video on Youtube. Or should I just trim them? I do want them to come back with lots of bloom. This year we had just a few blooms. Attached is a picture of one of them. I understand that the suckers need to be removed but what about the branches coming out of the bigger branches?
Any advice would be greatly appreciated!!

Thanks!
Jenn
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lilac tree.jpg

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applestar
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I don’t have lilacs, but cutting them down to a stump sound way too drastic — I HAVE heard that you want to cut the oldest trunks of the multi-stemmed shrub "to the base”- HOWEVER - I usually follow the “no more than 1/3 of total” RULE — this is said to protect the plant from going into shock.

Usually, the idea is to just select and lop the oldest gnarliest trunk — 2 or 3 at a time — that maybe are not blooming as well as younger, more vigorous ones.

I believe like other spring-blooming shrubs, you want to prune lilacs within a month or so after they are finished blooming.

Include in that ‘1/3 of total” some restorative pruning cuts to remove branches that are growing towards the interior rather than outward, and any crossing branches that are rubbing against each other (pick one), as well as if you want to shorten the shrub.


...just noticed you mentioned removing “suckers” — I don’t think that is correct. Lilacs naturally grow new trunks from the base, and those are the vigorous new trunks that would replace the old tired ones.

Vanisle_BC
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Location: Port Alberni, B.C. Canada, Zone 7 (+?)

I suspect JennMarie is correct in her reference to suckers on the lilac. We were given an ornamental lilac years ago. Before long wild shoots came up from the ground and the main trunk gradually died. What we are left with is a vigorous multi-stemmed wild lilac. Its blooms are nowhere near as showy as on the original plant but they are pretty and very fragrant. It has been neglected for 3-4 years and is now a tangled, leaning-over mess; much worse than the one in JM's photo. We like the tree/shrub and want to tame & rejuvenate it. Advice on doing so - hopefully while still getting some blooms - would be welcomed.

@JennMarie do you still get blossoms and/or growth on the original trunk? If not you may be left like us to choose having either a wild shrub or none. I feel sure the suckers are no friend of the original plant.

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applestar
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Haha Now I feel OLD. I’m used to my tech knowledge becoming obsolete but my horticultural know-how has generally been safe from obsolescence as long as I kept up with cultural discoveries and innovations.

Apparently, I’m clinging to the old-fashioned notion of own-root lilac being reliable hardy perennial shrub in colder zones and easily renewed with or propagated from root suckers.... :> I just don’t have them here because they prefer alkaline, well-drained soil — and my garden has neither.

I looked up grafted lilacs, and indeed this seems to be a common practice now, especially when it comes to lollipop-shaped lilac tree (I somehow missed that becoming popular ...vaguely recall starting to see it in fancy catalogs back in the ...80’s? 90’s?... but I remember thinking it defeated the aforementioned advantages of lilac....)


...If you are adventurous, maybe you know someone who has a nice lilac that you could try grafting onto the existing one? (I want to learn to graft, so I keep thinking it’s a do-able opportunity/option. :wink: )


...but getting back to the original premise — own-rooted lilac rejuvenation involves basically picking 5 or 7 or 9 (odd number preferred) vigorous juvenile to floriferous trunks and lopping the entire exhausted older trunks to the ground, opening up the interior to more light and airflow (lilac is susceptible to powdery mildew/fungal infection). If you want to reduce the size/height, prune back alternating trunks/branches by 1/3 over several years.

Vanisle_BC
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@Applestar I doubt you'd win over me in a 'who's older' contest but you certainly would on horticultural knowledge, of which I have little. I was completely unaware that anything other than 'ordinary' lilac existed, until the tree we were given started dying and the wild suckers took over.

Incidentally I don't think my soil is alkaline, here in this evergreen rainforest, yet the shrub thrives. Admittedly there is a tile drain close by so drainage is not bad.

Like you I toy with the notion to try grafting, but so far haven't done it. I feel sure I would fail. A few years back after reading of your tomato-crossing work I thought I'd have a go at that. Good grief, where do you get the eyesight & fine motor skills to even think of it? Never again for me. Thank goodness we can sometimes choose which challenges to reject!



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