Pruning forsythia the right way is vitally important - we show you why.
Pruning Forsythia right can make them a real asset to the garden, says Matthew Wilson
Despite its many virtues – fast growing, tough, easy-to-cultivate – Forsythia seems to suffer from a major image problem, to the point that some gardeners actively loathe it.
One of the reasons why, I’m sure, is the way in which Forsythia gets used in the garden – or rather abused in the garden – for if ever there was a shrub that suffered from the worst excesses of hacking and chopping, Forsythia must surely be it.
Forsythia grow rapidly, reaching maturity in comfortably under a decade, and this fast and sometimes slightly wayward growth is one of the reasons why they suffer from pruning butchery; if planted in the wrong place they can rapidly outgrow the space and lead to the inevitable chopping off of branches. But being vigorous by nature, the reaction of this shrub is simply to grow even more enthusiastically!
Forsythia is also a fairly popular choice of plant for hedges, and this is one application where I join the loathers. For me it just isn’t quite right as a hedge; not neat enough between trims to have the same qualities as yew, beech, hornbeam of even privet, and not loose enough to give it the natural look of a native hedge. And those vivid yellow flowers just look a bit odd embedded in the rigid geometry of a hedge. But well grown, correctly pruned Forsythia can be a real asset to the garden.
How to Grow
So how to grow Forsythia well? Firstly, give them plenty of space, and plant them in the right place where their vigour won’t be a problem. With maturity reached so quickly getting the right pruning regime in place is vital, and fortunately it’s really straightforward.
The timing is easy to remember – right after flowering. It’s important to prune then as Forsythia flower on shoots grown the year before flowering, so if you prune too late you’ll be removing the flowers for next year. After five or six years it’s a good idea to remove about 20% – 30% of the oldest stems completely, right down hard to the ground. This will stop the plant from becoming congested and improve air circulation, reducing the risk of disease.
A decent feed with garden compost or well-rotted manure, and a good drink of water if the conditions are dry, and that’s about it. Once the flowers are over the plant steps out of the limelight until the following spring when those golden yellow flowers appear once more. With proper care, you need never loathe Forsythia again.