Why Won’t My Forsythia Bloom?

– Posted in: Forsythia

The forsythias bloomed later than usual this year, sometimes overlapping with the earliest lilacs–but they did bloom. If yours didn’t bloom, here are some things to consider:

Meadowlark forsythia is bud-hardy to -35F.

My neighbor Mike’s forsythias backlit by the sun.

Improper Pruning

The flowers for forsythia are set the year before they bloom. That means if you prune your shrub too late in the season, you will cut off the wood that has the flowers growing on it. The standard advice is to prune forsythia about two weeks after it’s done blooming. Don’t shear it like a hedge, but cut entire branches down to the ground. I prefer to prune my forsythia in very early spring, because it’s a lot easier to see what to prune. Those branches won’t bloom outdoors, but I force them indoors for a little early spring sunshine.

Too Much Shade

Forsythia needs full sun. You probably read the tag before you planted it, and planted it in full sun–or what you thought was full sun. It could be you planted it before the trees leafed out, and didn’t realize a tree would shade it. Perhaps you planted it on the sunny side of the house, never realizing it was in shade all afternoon. Or maybe you really truly did plant it in full sun, but several years later, other trees and shrubs have grown and now shade it. Take a good hard look at your forsythia’s location at several different times during the day to determine if this is the problem.

Too Much Neglect

If you don’t do any pruning to your forsythia for several years–like I did–it can start to shade itself out. You need to renovate the shrub. Even more detailed directions for pruning forsythia can be found here.

Meadowlark forsythia, bud-hardy to -35F

My ‘Meadowlark’ forsythia was getting kind of scraggly before I took the pruners to it.

Too Darn Cold

The fact that forsythia blooms on old wood is one reason why some northern gardeners get little or no bloom on their shrubs. Those delicate little buds don’t always make it through the winter. I was sure glad I found this out before I plunked bought the forsythia of my childhood, ‘Lynwood Gold.’ ‘Lynwood Gold’ is rated hardy to Zone 4, but it’s only bud-hardy to Zone 5–in a good year.

Bud-hardy forsythias

I grow ‘Meadowlark,’ which is supposedly bud hardy to -35F (-37C). (That makes it hardy to USDA Zone 3.) Fortunately, I haven’t had to personally verify this. You can also look for ‘Northern Gold, ‘Northern Sun,’ ‘Vermont Sun,’ ‘New Hampshire Gold,’ or ‘Ottawa,’ which are all supposed to be bud-hardy to USDA Zone 4.

Meadowlark forsythia hardy in cold climates

A well-grown ‘Meadowlark’ forsythia gets big. (Also one of Mike’s.)

One day I would like to grow all these bud-hardy forsythia side by side to see what the differences are.

About the Author

Kathy Purdy is a colchicum evangelist, converting unsuspecting gardeners into colchicophiles. She would be delighted to speak to your group about colchicums or other gardening topics. Kathy’s been writing since 4th grade, gardening since high school, and blogging since 2002.

When dealing with frost it is always best to be paranoid. In the spring never think it is too late for one more frost to come. And in the fall never think it too early.

~Rundy in Frost

Comments on this entry are closed.

James July 28, 2014, 10:33 am

I love Forsythia and this is one of my favorite plants when I do my garden landscaping. Yeah, sometimes it takes time to bloom but it will definitely blooms if you care them right.

Frank June 1, 2014, 8:02 pm

Forsythia season seems ages ago now that we’re finally getting some warmer weather. I don’t have any in my garden right now but growing up we spent many a summer day cutting back forsythia. I didn’t even mind it much since the branches were soft, there was no sap or thorns, and any mistakes would grow out within a couple weeks!

Donna@GardensEyeView May 31, 2014, 2:08 pm

I got rid of all but one of my forsythias as they had too much shade and too much cold….I have one dwarf variety that is in full sun and is buried by the snowblower every year but boy does it bloom no matter what.

Shane May 28, 2014, 6:24 am

Many thanks! I had been battling this same problem with my forsythias! Will definitely try all your suggestions here.

Kathy Sturr of the Violet Fern May 27, 2014, 7:19 am

Thank you! I vowed I would prune my forsythia this Spring. Now I have even more confidence and incentive. It didn’t bloom this year even though, I too, have Meadowlark. It did begin blooming last Fall, followed by a cold winter, and lastly I haven’t pruned it … It all adds up. It hasn’t even fully leafed out yet so I have no excuses but to prune!

Kathy Purdy May 27, 2014, 3:08 pm

My Meadowlark always throws out a few blossoms in fall, but not in a big way. Good luck with your pruning job!

Rodrica May 27, 2014, 4:43 am

Finally! You’ve answered my question as to why some forsythias bloom well, even this year, and others in the neighborhood only bloom below the depth of the winter’s snow. Thanks.

Joanne Toft May 26, 2014, 9:09 am

I have a very little Forsythia that – it has not died, it has flowered every year but it is not getting any bigger. ( I know I have to watch for the rabbits who like to eat it in the winter but I am not getting any summer growth. Any thoughts on how to encourage some growth?

Kathy Purdy May 26, 2014, 12:23 pm

Forsythia is supposed to be easy to grow, hard to kill, so I would say something in the area is competing with it. If it has flowered, I would think it is getting enough sun. Perhaps it is in a very dry spot? Or–you don’t say what the cultivar is–perhaps it is a dwarf variety and is just not supposed to get very big?