Ah yes…my wonderful habit of forgetting to prune right after certain shrubs are done blooming. Yup…once again I am a few weeks late, but fortunately next years flower buds have not yet begun to form. So how many of you have giant overgrown lilacs, viburnums, or forsythias? I do! I do!
The house that I am currently living in has a huge overgrown lilac in the backyard. Last year I gave it a pruning and this year I have once again hacked and sawed and cut to try to get it back down to a manageable size.
I pruned probably 1/3 of the growth out of it last year later than I probably should have, oh say July. Fortunately, I was still ahead of bud formation and this year it bloomed beautifully. Of course who constantly forget to get out the camera to take a picture? This sprout. Oops.
So, the above picture is before I pruned on it. It actually is best to prune spring blooming shrubs right after they are done blooming in the spring. Remove 1/3 of the oldest growth every year. It encourages new growth and better flowering. Please don’t wait until September to prune them…you end up removing next years flowers. Yeah, go ahead and ask me how I found that one out.
Next year I’ll remove the last cluster of large stems. The other reason I’m doing this is it’s getting awfully close to some overhead wires and I’m trying to avoid that. The lilac looks a bit odd right now since it looks kind of sparse and awkward, but later in the summer it will fill in. I promise and I’ll try and remember to take a picture to show you.
So, if your spring blooming shrubs need a haircut the time is now!
The Garden Sprout 
This I did not know!! I too had a huge massive overgrown dwarf lilac when I moved in, I pruned the crap out of it the first spring but, last yr I pruned it in the fall and it seemed to not last very long. How long should it be in bloom for? I love your blog, already learned something new!!!
Usually lilacs bloom for a few weeks. By September they are already starting to develop flower buds for next year. Just prune out 1/3 of the oldest growth each year for three years and it does wonders. You’ll want to prune the oldest growth down as far to the ground as possible too. Glad you learned something new!