When to Prune Forsythia and How to Do It Right – So You Don't Lose Any Blooms
Learning how and when to prune forsythia bushes is key to their care. Do it wrong and you may lose all your blooms. Here's how and when to make the right cut.
Laura Walters
Forsythia pruning is an essential task to keep shrubs shapely, prevent scraggliness, and ensure good blooming. It's important to understand how to prune forsythias the right way and the right timing for trimming, otherwise you might miss out on those glorious spring flowers.
Blooming forsythia bushes are a sure sign of spring. Their bright yellow flowers appear on bare branches before these fast-growing shrubs leaf out for the season. They are a fantastic addition to any garden. But they have a tendency to get a bit overgrown and unruly. That's why learning how to prune them properly is key to maintaining these shrubs well.
I'll walk you through how to prune forsythia bushes, common signs it's time for a trim, and share some major pruning mistakes to avoid so your shrubs look great for years to come.
Article continues belowEssential Forsythia Pruning Tools
These basic pruning shears are perfect for thinner stems on forsythias and the other bushes in your yard.
For thicker branches, break out the loppers! They make quick work of old, woody growth.
Turn forsythia cuttings into new plants! Dip stems into this rooting powder and plant to expand your garden for free.
Signs It’s Time to Prune a Forsythia
Generally, you should trim your forsythia bushes at least once a year. But if it’s been a while, there are some clear signs that will indicate when your forsythia needs pruning.
Forsythia bushes grow quickly. If your shrub looks large and overgrown, it is definitely in need of a trim. It may also look unruly and unattractive. When that happens, it's time for a forsythia rejuvenation pruning.
If you haven't pruned your shrubs in several years, this can also result in forsythias not blooming. A well-executed trim will solve this problem and ensure you have lots of blooms the following year.
When to Prune Forsythia
Knowing when to trim forsythia is essential for plentiful blooms. Prune at the wrong time and you will see fewer flowers. But if you prune at the proper time you will have fantastic flowering. The best time to prune a forsythia shrub is in late spring or early summer after they’re done flowering.
Forsythias bloom on old wood, so they begin to develop their flower buds as early as midsummer for the next spring. If you prune too late in summer or in the fall or winter, you’ll trim off those buds and have fewer flowers – or none at all – the next season.
If you have a very overgrown forsythia that isn’t producing many blooms anyway, the timing for pruning is less important. It’s better to hard prune older shrubs while they are dormant in late winter or very early spring.
How to Prune Forsythia
When pruning forsythias or any plants in the garden, always use sharp, sterilized pruning tools. This helps prevent the spread of diseases and pests. Though pruning can rejuvenate and revive old shrubs, it also makes them vulnerable until the cuttings wounds heal.
For thinner branches, use a sharp pair of gardening shears. These Felco F6 hand pruners from Amazon are a favorite of both professional and home gardeners. A pair of loppers or a hand saw are best for thicker branches on older shrubs. The Fiskars 28" Loppers (from Amazon) are a good option for trimming mature shrubs and trees as well.
When trimming forsythia shrubs that are not badly overgrown, start by removing about one-quarter of the old wood branches. Remove them evenly throughout to open up space within the shrub. The oldest stems are the thickest at the base and usually the tallest. Removing these will reduce the overall height of the shrub.
Next, focus on any crowded thinner branches that are higher up in the shrub. Cut off these smaller branches where they stem off of a larger branch, just above a node. Cut at a 45° angle to reduce the chances of disease and help plants heal faster.
After that, remove branches strategically. Follow these basic pruning guidelines:
- Trim off branches that are dead or damaged.
- Remove any branches growing in toward the center of the shrub.
- Remove one of any pair of branches that are crossing or rubbing against each other.
- Trim back some of the tallest, most vigorous upright shoots to control height.
The goals of trimming should be to open up the shrub to allow more light to the interior, to control its size, and to maintain a pleasant growth pattern. The natural shape of forsythia is fountain-like.
Resist the urge to simply go over the top and sides of your shrub with hedge trimmers to trim it into a uniform forsythia hedge. This is not the best way to prune a forsythia shrub. Instead, work with the natural growth habit for the most beautiful results.
Frequently Asked Questions
How Do You Prune an Old, Overgrown Forsythia?
A neglected, overgrown, and wild forsythia can and should be trimmed back severely. While dormant, trim the shrub back to one foot or less (30 cm). It will regrow vigorously the next season, so don’t be afraid to cut it way back. Within a year or two, you’ll have a refreshed shrub that will bloom prolifically.
What Happens If You Don't Prune Forsythia?
If you don’t prune forsythia shrubs once a year or at least every two years, it will become overgrown and unruly. Overgrown forsythias lose their attractive shape. They also bloom less. As forsythia stems age, their ability to produce flowers decreases. It is important to remove the oldest branches each year to promote new growth and more blooms.
