April Pruning of Forsythias

In the first week of April, while fall-planted garlic cloves are still encased in ice, I will take on any chore that gets me into the garden.  So when the receding snow revealed the top portion of a downed spruce lying across the forsythia at the end of the driveway, I jumped at the chance to try out the machete I got for Christmas.  Chopping through the pulpy trunk, I divided the long-dead tree into movable sections and liberated the forsythia.  Fifteen minutes of chopping and my shoulder joints were reminding me that I had been cooped up at the writing desk for too many days!

Trading the machete for pruners and loppers, I cut back forsythia twigs and branches that had been damaged by the fallen snag.  At this point, I ignored my own best advice about the time to prune spring-flowering shrubs and forged ahead with the complete annual pruning of the forsythia before it had bloomed!  You could say that I fell back on a old paradigm: prune when the pruners are sharp.

If the goal is to maximize the number of flowers, pruning a spring-flowering deciduous

A properly pruned forsythia hedge is a beautiful harbinger of spring.

shrub should be done as soon as the plant stops flowering, not before it blooms.  Yet other than removing a few flowers, I still achieved the main objective: enhancing the proportion of young, floriferous branches in years to come by removing one-third of the branches, choosing the oldest and thickest as the first to go.  And I did this at a time when branches could be easily seen and reached.

Such early pruning does reduce the total number of flower buds, but it also creates a more open and graceful plant on which the remaining flowers will be displayed.  And early pruning will likely produce several cut branches for forcing indoors, an early touch of spring.

I pruned with the knowledge that forsythia flower buds form during the summer on two-year-old branches that grow off of older branches or from ground level.  As a branch grows old, its production of flowering shoots is reduced and plants with an abundance of old branches thicker than an inch in diameter often bear few flowers.  By removing the oldest branches every year, my forsythia will never be crowded with thick stems that bear few flowers.

I cut each selected branch back to the ground or to within a few inches of the ground, varying the height of the cuts to maintain a natural form and making each above-ground cut just above an outward facing bud.  New stems will grow from lateral buds to replace the old stems and these new stems will grow vigorously during their first year and flower profusely in their second year.

As I pruned away the tired old stems, I also removed all dead, damaged, or diseased stems, again making each cut either just above an outward-facing bud or at ground level.  Pruning for these “three D’s” should be done throughout the year, whenever they are noticed.

Working on this forsythia in the cold sunlight of early April, I thought back to a road trip from Ellsworth to western Massachusetts that Marjorie and I had taken a few years ago, a late April view of the advance of spring in rapid motion.  Beneath the soft and subtle golds of willow and oak, the bright yellow of blooming forsythia was everywhere.  I remember thinking that Massachusetts must offer tax breaks to homeowners who grow this herald of early spring, for few properties were without at least one shrub and some citizens were competing with the highway department for the largest colony.

Early in the trip we decided to document the many forms that forsythia assumes in home landscapes.  We photographed wild and woolly hedges that had not been pruned in decades, their slender flowering branches twisting into the light from a tangle of old, woody stems.  Other informal hedges, open and airy and far more floriferous from top to bottom, reflected the care of annual pruning.  And there were all of the tortured forms, meatballs lined up along the property line, hot-air balloons flanking the entrance drive, and flat-topped plants that might be used as garden benches.

For my taste, the best forsythias are those managed to enhance their natural growth habit, slender branches that grow upward and outward, stiffly arching down to earth under the weight of spring flowers.  This can be accomplished with a single plant, or a small grouping, or a long informal hedge.

Pruning forsythias, even informal hedges, should be done with hand-pruners, loppers, and a small pruning saw.  Under no circumstances should any form of pruning shears be used!  Shears lop off stems at indiscriminate points – you want to make each cut just above an outward facing bud.  Also, shearing plants into unnatural forms removes many flowering stems and shortens the length of others, thus reducing the total number of flowers.

This entry was posted in Ornamentals by Reeser Manley. Bookmark the permalink.

About Reeser Manley

I was born in Laramie Wyoming but moved to the southeast at an early age. I was educated through my B.S. in Biology in the Columbus, Georgia area, then crossed the Chattahoochee River to earn my M.S. in Botany at Auburn University. For the next ten years, I worked as Horticultural Manager for the George W. Park Seed Co. in Greenwood, S.C. At 40 years of age, I decided to return to graduate school and in 1994, I earned a Ph.D. in Horticultural Science from Washington State University, Pullman, Washington. Fast forward through 10 years at university (7 at UMaine, Orono) and you find me teaching high school science in Eastport, Maine, the edge of the world, and writing a weekly garden column for the Bangor Daily News. My new book, The New England Gardener's Year, a Month-by-Month Guide for Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, and Upstate New York”, will be published later this year by Cadent Publishing. You can learn more about the book by visiting its Facebook page: http://www.facebook.com/pages/The-New-England-Gardeners-Year/187285218055676.)