I have a large lilac in my yard that has grown to about 10 ft high. The last few springs it has had very few flowers on it, and I felt that maybe a good pruning would help it (not to mention I might be actually able to reach the flowers if it were smaller). What time of year is it most beneficial to prune and how much can I safely take off of it without hurting the plant?

Thanks

You and me both, shelster. Mine got to a similar height and so I took garden shears and saw to it about three months ago. So far, the bush seems healthy enough, but at 8 feet high seems to need tying up as it's leaning out too much, probably because it had grown so tall. Should I be giving thought to maybe tying what's left into a closer formation to try and achieve a tighter bush again?

Sorry to have not seen this sooner...for both of you, THIS site has some really great info!

Good luck! Lilacs are by far my favorite flowering plant!!!!

Excellent link, gizmogram - thanks. At least lilacs seem to be hardy, thriving bushes so it seems like I can't have done too much damage! I'll follow some of the guidance and bookmark the site for future reference. Thanks again.

Well, the lilac's doing pretty well this spring! When we first planted it, the flowers were all white, but then gradually the traditional lilac colour took over. After all the pruning though, the white colour is prevailing again, all except one growth. So what should we do to retain the white-hued flowers, which is what we prefer? Help!

Sounds, Colin, that the lilac you have has a rootstock which is the original lilac and the white lilac has been grafted on to it. That's a universal practice with rose bushes and is fairly common with other shrubs. The reason is that the original stock is a vigorous strong plant (and very cheap: it may be the wild lilac !). The grower grafts on to the rootstock a sprig of whatever hybrid he wants. That gives a fine shrub of the hybrid (and also means that one hybrid plant can be used to make hundreds of little new ones).

Unfortunately the original stock may send out 'sports', shoots of itself, which have , naturally, all the colour and characteristics of it.If you clamber in to the shrub you'll see, right at the bottom, the points where these original shoots of lilac colour are coming from. Cut those out at the base. They'll all be shooting from below a small lump which is the grafting point at which the new white plant was grafted on. Sometimes this point is now below the soil surface.That's unfortunate because the plant is encouraged by that to shoot from below the surface. That's nature's way.So, while you are in there, clear any soil which is covering the grafting point.

Otherwise, all you can do is cut back the lilac colour shoots as low down as you can reach. If you don't, in time the whole shrub will revert to the original colour. That's because the original stock is a lot more vigorous than the shrub grafted on, one reason why grafting is done in the first place.

There must have been white lilac at some time, that is a true white shrub, which occurred naturally as a chance white plant, which is the ancestor of all garden white ones.It may be that some very old varieties, like Madame Lemoine, are true white and were vigorous enough to be grown ungrafted, but that's not likely to be the case with most.

Very useful advice this, Fred. I'll investigate closely when I return from holiday.

A quick update here. I'm back from holiday but still at the cutting-the-grass stage (rather than the tidy-up-the-bushes phase). It's 28° here too, which doesn't help my "let's get down to it" approach. Maybe Im lazy. Anyway, as the mower and I whizzed (plodded) past the lilac bush this afternoon, I had a quick look onlt to see that the pretty white/lilac flowers have already gone. Now what do I do?!