Forsythia before pruning began

Back in April, I discussed my upcoming plans to prune my forsythia bush. It wasn’t flowering very much, and my commenters agreed with me that it needed a heavy pruning. Some even suggested cutting the whole thing down to the ground. But I felt a little too nervous to do that.

Cutting it down to size

On May 13th, less than two weeks after the forsythia finished blooming, I decided to drastically thin it. I asked my son Collin to do the actual cutting, because I really don’t have the upper body strength for a long stint of pruning with loppers, and I don’t have the flexibility to get inside a shrub like that without paying for it for a week afterward. And besides, it was Mother’s Day.

At the top of this post, you see what the shrub looked like before the pruning. If you look carefully, you might be able to discern Collin’s white shirt near the bottom of the shrub, as he was getting ready to make the first cut when I realized I needed a before picture. I asked him to cut everything that was 3/4″ (approx. 2 cm) in diameter or larger. He pruned out all of this:

All these branches were cut from one overgrown forsythia

And the forsythia looked like this:

This is what it looked like after the pruning was done

Hardly encouraging.

Growing Back Nicely

Don’t let it scare you. My shrub is growing back nicely.

Look at all that thick new growth! (Photo taken June 30th)

Those branches coming out every which way are the ones that were not pruned out in May. They still have leaves on the tips, but have not really made new side branches along their length. I’m wondering if I should have taken them out. If the whole shrub flowers next spring, I will definitely cut them out. (Or should I say, “have one of my kids cut them out,” since that’s probably what will happen.) But if they are the only branches that bloom next year, I will be glad to have left them in. Update: Just found this great tutorial on pruning forsythias.

What scary pruning job have you tackled? How did it turn out?

Remember the forsythia I pruned so that I could force some branches? It doesn’t look so floriferous out in the open, does it? (For comparison, check out the forsythias here.)

When I’m faced with a plant that’s not doing as well as expected, I try to analyze the situation before taking action. In the case of the forsythia, I observed that the flowers were only on the ends of the branches. If it were cold damage, I would expect the flowers below the snowline to bloom, and the ones exposed to the cold higher up on the shrub to be missing. That’s not the case, and besides, this variety of forsythia is supposed to be bud-hardy to 30 below zero Fahrenheit, and it didn’t get that cold this winter.

I know that most flowering shrubs need lots of sun to give them the energy to form flowers, and I think this is getting closer to the problem. At first, I thought the lilac bushes on either side were shading the forsythia too much, but that doesn’t quite fit with the blooming pattern. All the missing flowers are towards the center of the shrub. I’m coming to the conclusion that the forsythia is shading itself too much, and needs a substantial thinning.

So in a week, two at the most, I’ll use my loppers to prune the thickest branches as close to ground level as I can manage. I hope this will let more light into the center of the shrub, enabling it to produce more flower buds for next year. If that doesn’t help, I’ll have to suspect the general root competition from those lilacs. If that’s the problem, the choices are:

1. Remove one or more lilacs
2. Relocate or get rid of the forsythia
3. Make an effort to give the forsythia more water and perhaps fertilize it
4. Reconcile myself to a less than optimum display

Given those choices, I will probably go with number 4. I don’t want to get rid of any of the shrubs (they do their job of screening us from the road quite well), and anything I do to help the forsythia in terms of extra water will no doubt help the lilacs just as much. The point of the forsythia is to give me pleasure in spring, and it does that, even without a maximum amount of bloom. I find that bright yellow immensely cheering. I need it; I want it; I’m gonna have it–but I know I don’t have time to baby it. For me, that’s an acceptable trade-off.

A Reader’s Forsythia

Recently, a reader commented:

We just bought a house and the forsythia is very overgrown and old. It has many branches deep inside the bush that have nothing at all on them. Do we try to cut out all those old, non-blooming branches and hope for the best? We love forsythia. Help!!!!

This sounds like the same problem my shrub is having, only to a much greater degree. If a branch truly has nothing on it–no flower buds and no leaf buds, either–the branch is dead. By all means, prune it out. For branches that have leaves, but no flowers, the first step is to look around the shrub. Are other trees or shrubs shading the forsythia in summer? If so, no amount of forsythia pruning will help. You’ll have to prune away whatever is shading the forsythia, and that might not be worth the ugliness that might ensue.

You also have to consider if the forsythia isn’t bud-hardy for the climate. Any forsythia in the warmer part of zone 5 and south of that should be fine.

If both the above conditions don’t seem to be the problem, it does sound like a radical pruning is in order. Forsythias are very vigorous shrubs, and many people would advocate cutting the whole thing to the ground, watering and fertilizing well (using fertilizer suitable for flowering shrubs), and letting the shrub rejuvenate itself.

That’s just a little too scary for me. A more conservative approach is to cut out one-third of the branches for each of three years, gradually bringing the shrub into a more productive growth habit.

A “new” garden needs patient observation

When you first move into a house, you’re all excited and you want to roll up your sleeves and whip everything into shape. But really, the best thing to do is to wait a year and observe your property through the four seasons, taking lots of notes. For my first spring at this place, if I had assumed that the foliage coming out of the garden beds was old tired tulips that were no longer able to bloom, and had dug them out immediately, I never would have seen the colchicum blossoms that fall, and discovered a plant that has fascinated me for years since. Having said that, I can’t see how it would hurt to thin out your forsythia by pruning it this spring. Just watch where you step, there could be another plant growing at its base!

What discoveries have other gardeners made when they first moved into an established yard and garden?

The standard advice for pruning spring-blooming shrubs is to prune them no later than two weeks after they’re done blooming. This is because most spring-flowering shrubs, at least, all those commonly grown, develop their flower buds on the previous year’s wood. So if you prune them in high summer, or autumn, you are cutting off the wood that has the next spring’s flowers.
However, it is far easier to see the structure of the shrub you are pruning in late winter, when the temperatures have moderated somewhat but the shrub hasn’t leafed out or started blooming yet. And, in the case of forsythia, you can bring the prunings indoors, stick them in a container of water, and, in about a week, have forsythia blooming in the house. These in the photo were cut about a week ago, on one of those nice days just before winter returned.

Since the forsythia outside will be blooming in another week (or two, weather depending), some people might wonder, “Why bother?” I can only speak for myself. At a time when the mild weather has vanished and interminable gray days with flurries have taken its place, forsythia blooming in the house is incredibly cheering. And if past experience holds true, it will not dampen in the least my appreciation of forsythia blooming outside later this month.

And I’ve accomplished two goals at once: I thinned out a shrub that needed it and brought in blooms for the house. According to this article, forsythia branches can be brought in as early as January. Hmph. Maybe if there’s a spring thaw about then. I personally can’t bring myself to do much more than run down the driveway to our rural mailbox and run back with the mail when the wind is blowing and the snow is flying. Not to mention that the branches that need pruning might be under snow. Also, the closer in time to the natural blooming of the shrub, the better the results.

Bud-Hardy Forsythias

The fact that forsythia blooms on old wood is one reason why some northern gardeners get little or no bloom on their shrubs. (The other big reason is growing in the shade. Unless you pruned all the flowering branches off. Duh.) Those delicate little buds don’t always make it through the winter. I was sure glad I found this out before I plunked down my plastic for 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. I grow ‘Meadowlark,’ which is supposedly bud hardy to -35. (That’s minus. thirty-five. degrees. Fahrenheit.) 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 Zone 4.

Further Reading

For those of you who save all your back issues of gardening magazines, here’s some more information on forcing branches:

• Ann Lovejoy, “Boughing to Spring,” in Horticulture (February 1994), pp. 44-48
• Wayne Winterrowd, “A Harvest of Winter Color,” in Horticulture (November 1998), p. 32-38

This is a photo of my Forsythia ‘Meadowlark’ blooming–sparsely, I grant you, but nevertheless blooming–in September. If I hadn’t been checking for signs of the colchicums recently planted in this area, I’m sure I never would have noticed the yellow blossoms, so it is entirely possible this shrub has done this other years without my being aware of it. On the other hand, dinner table consensus was that it had bloomed pretty poorly this spring, so maybe these were flower buds that didn’t “get it” this past spring. Worse, these could be next year’s flowers jumping the gun, in which case there may well be another sparse flush next spring. I’ll keep you posted. And if anyone else knows of a fall-blooming forsythia, I’d love to hear about it. [Photo taken 9/14/04]