Question
QUESTION: I read a Q&A here from March about forsythia.  My question is related.  Our forsythia (in Toledo,OH) forms a hedge which needs frequent trimming. It grows as fast as a weed! It almost never flowers because it is trimmed frequently throughout the season.  I accept that I can't expect flowers.  I just want it to be full and healthy.  But now it is so large that it's hard to reach across it to trim it.  I had heard that it should be cut back in the fall, but I'd like to do it now.  It's about 5' tall and almost as wide.  I'd like it to be at least a foot shorter and only 3' or 4' wide.  Can we cut it back now or must we endure another season of trimming?  If it's cut back now, will it leaf out quickly or just look like bare sticks?  The foliage is most dense at the tips from so much trimming.  And with the dense tips gone, the rectangular shape will probably disappear.  I can accept it looking bad for a short time if it fills out in the long run.

ANSWER: Hello Vikki

As you probably read in the March Q&A, forsythia should be trimmed right after the flowers have faded, which means about now.  After that the plant will put on a spurt of growth and this new growth will carry next springs flowers.  So - the more you cut it now, the more it will grow to try to have new growth for next year!

The fall would be the best time to prune if you want a hedge (although I have to say that forsythia isn't really a plant I'd recommend for a formal hedge), but if you cut it now it is still early enough in the year for it to send out new shoots and thicken up.

I suggest that you cut the hedge down a foot lower than the height you ultimately want - as you have noticed, most of the new growth comes from the cut area of the stems.  Another ploy to get a hedge that is leafed down to the ground would be to cut some of the stems out at the bottom, some a foot above that and so on, so that fresh, new growth will spring up from each cutting point.

When you have cut the hedge down by 2 feet you may find it easier to reach across it in future, cutting half from one side and half from the other side!

I do hope this has helped.

Gill  

---------- FOLLOW-UP ----------

QUESTION: That's a good tip about cutting some of the stems closer to the ground so that there will be new growth there as well as at the top.

It sounds like I could cut it down some now, but you think the fall would be the better time.  I'm anxious for it to be cut back, but I'll wait until fall if the long term result is better.  Do I need to wait for cold weather to start?  I think in years past, although it grows like a weed most of the summer, the growth slows, almost stops, at the first sign of cool weather (I forget how early - the end of August maybe?)  When new growth stops, if I cut it then, I wonder if September weather could make it grow too much?  Should I wait until leaves are falling?

Thank you!

Answer
Hello Vikki

You could cut some back now for the sake of tidiness and do the main job when growth slows down at the end of August or beginning September.  I don't think there is any real need to wait until all the leaves have fallen.  

Next year you should see a definite thickening up of the hedge and it will be easier to keep it that way in future years.

Hope this is helpful.

Gill