Lilac tree

[ByThePowerOfGreyskull]

I have a lilac tree in the garden that is over 15ft high,
it hasn't had the love and attention it deserves since we had DS1 7 years ago, and it is now needing help.

I have found a great site telling us that we should hard prune 1/3rd of the branches this year, the same next year and the same the year after (because we aren't brave enough to hard prune it all at the same time and wait 3 years for more blooms)
However it doesn't say what time of year would be best.
It says to prune straigh after flowering but isn't that just to remove the dead flowerheads?

I have to post and run out for the afternoon but will be back later.
Any help will be greatfully received! TIA x

this link suggests doing it in spring if you're going to do this kind of serious pruning, so that you can see all the stems better without the leaves on it. Good luck - they do get enormous if you don't have the chance to keep them under control!

If you prune straight after flowering - which would be early summer - then you'd take out a few decent length branches rather than just the dead heads. The advice to do it in stages is probably because lilac flowers on old wood. If you pruned the whole thing in one go, in other words, you might have to wait a whole year or even two before it flowered again.

thanks ladies,
so, current plan, to leave alone at the moment as the flowers are just opening so once the flowers have gone and before we get too many leaves (so we can see what we are doing) to take back 1/3rd of branches really hard.

does that sound about right?

we attacked ours about 6 weeks ago, removed 3 huge branches, but they were mostly dead anyway as it was pretty neglected by previous owners. No idea if it will flower this year, but it was awfully satisfying to take it in hand. I think your plan sounds sensible- they are such lovely flowers you don't want to spoil that now! If you have a woodburner, the lilac wood burns brilliantly by the way!

I think that's about right BTPOG. I have a Philadelphus that I have to do the same thing with. Means I always have flowers on the 1/3 older wood, no flowers on the 1/3 new wood and 1/3 pruned waiting to sprout for next time. By contrast my (white) lilac never seems to need pruning at all... strange. Good luck

This is interesting. Do you mind if I hijack for some advice on our old lilac please???

Our lilac is about 15 foot tall, but it's growing at an angle. I'm confused what's best to do with it I'd quite like to let it flower one last time (incase we kill it by mistake!) and then take it in hand. If we cut it right down to 6-8" as suggested in the link, will it really sprout from the bottom? ATM there is just a tall smooth trunk with no branches until quite high up the tree! It's hard to believe it could do anything but die if we were so brutal, but it would be great if we could just cut it right down and start again, I really really love the smell!

Thank you

I guess the first question is - Are you sure it's a lilac? They usually have lots of stems all growing up from the ground together, not a single solid trunk - that's why they're classed as a shrub and not a tree.

If its just got one big trunk, it could perhaps be something else - not sure what though - but I'd certainly not cut a tree back to ground level and expect it to come back.

I think it's a lilac... It certainly smells and looks like lilac... Googling it, there seems to be both lilac shrubs and lilac trees, but I can't find a picture of one to compare. Hmm..