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Renovating a lilac tree


We have an old lilac tree that is getting too big for it's situation and so I need to consider how best to cut it back and re-shape it.

I've looked at pruning tips for the job and the advice seems to be to take out a third of the stems down to ground level and re-shape over a three year period. What isn't clear is which stems to take out, thick ones, medium ones or thin ones.

Ideally as well as thinning it out a bit I would like to take it down by a couple of feet, which I think realistically means losing the flowers for next year anyway, so I'm wondering what the best approach is.  I know I need to get on with it - I think I'm already a bit late, but things are running behind since our flood in June, so this is the best timing I can do.

Thoughts welcome, pics below. It was a tree with one thick stem and a few thinner ones, but the thick one broke, so what's there now is what has grown up over the last 17 years, with little or no pruning or tending in the interim. It is providing too much shade for the peony and rhododendron so something needs to be done!



image This shows the base at the front where there are a number of new but spindly shoots growing up - spindly through lack of light I imagine

image And this is it from the side


  • Paul B3Paul B3 Posts: 3,063

    Hellfireimage I'd cut it to ground , miss a couple of years flowering and start afresh by regular pruning .

  • That's an option but I wonder if it is possible to do it gradually so we keep some flowers. It produces lots of flowers and looks lovely, it's just bigger than we'd like

    If we cut the thickest stems right back but left the newest growth, any thoughts on how soon they might flower? The newest growth is a bit spindly due to looking for light and so will need cutting back a bit. I had hoped to get it done this weekend but the weather is against me so it will have to be next weekend

  • mushermusher Posts: 389

    I tend to agree with Paul, it's a well established Tree..You'll be astonished at how fast your new shoots will grow. After that Prune, don't prune it again for 2 to 3 years. Until once again you get a show of good flowers. Then I'd just take out any thing that grows up through the centre. Good Aeration is important to prevent such dieases has Lilac Bacterial Canker.The rest of the Tree just pune it back by a few inches. not a third. These next couple of years you may not see any flowers at all. Only feed it with Fish bone and blood.

  • mushermusher Posts: 389

    By cutting down the main stems and leaving the young shoots. You'll still have a poor showing of flowers. So you mean't has well start again. 

    If you ever get another Lilac. Don't prune it at all until it gets well established and bearing a good show of Flowers.

  • raisingirlraisingirl Posts: 6,651

    If it was mine I'd take out all the stems on the right of the first pic, where it's overhanging the bottom flight of steps, right to the ground. Then see how it looks next year and take out or down the ones on left as you need to for balance and to get the shape you want as you the new growth comes up.

    They are tough and I'm sure the advice above is right and it would survive a drastic cut back, probably being better for it in a few years. But that wouldn't be my choice.

    “Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first” 
  • Thanks raisingirl, I'm leaning less towards really drastic action. I don't know how old the lilac is, it was here in 2000 and was a big tree then. Due to work we only lived here for 4 years and were then away for ten, so since 2014 we have been gradually tackling jobs inside and out. The garden is huge, so the lilac has only recently come to the top of the pile, partly because getting down into the garden became an expedition this year!

    I recently planted a new lilac elsewhere and the advice on that is welcome - I'll leave well alone until it is established

  • So I'm half way through the renovation and there are a number of what look like new green flower buds and if I didn't know better I'd say it looks like it might flower again, but lilacs don't do that kind of thing!

    There are also brown flower stems from the old flowers so the green ones just might not have gone brown yet but that seems a bit late really

    Before I lop off what could turn out to be next year's flowers, can anyone enlighten me please? Sorry to be dim here but I've never noticed these buds at this stage in previous years and as they are at eye level I would have thought I would have seen them before

    Apologies for the slightly blurred pics but it is windy today!


    The green buds are in the middle of this pic


    This one shows some brown and some green buds

    Last edited: 22 July 2017 19:26:11

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