Last post focused on the radical renovation of forsythia, as an example of how cane-growing shrubs can be ‘refreshed’ by cutting them back severely very occasionally. Today I’m posting a series of photos illustrating one method of renovating a tired yew (Taxus) hedge.
The driveway renovation in these photos required that one drive entry be moved uphill slightly. To do so required that we remove a couple of shrubs from one end of the hedge; the other shrubs stayed in place.
6-foot high Taxus hedge before renovation
The owners of the house were very attached to these plants, but weren’t pleased with how tired the plants looked: they were narrow at bottom and wide at top, they had been sheared for years, and as a result were now leggy and sparse.
To preserve the shrubs, in 2006 I asked the arborists to cut the shrubs down and thin them out from the interior. Originally, the outer branches were supposed to stay, with the severest thinning to happen inside, behind a wall of older foliage. The crew missed that part, and really went to town on the hedge. The client saw the work only after the crew had left, and was understandably concerned.
When I went over to look at the newly cut hedge — now lowered to 3′ in height, and drastically thinned — from a distance it looked horrifying. It looked horrifying close up, too.
Taxus hedge cut down to 3' height, and thinned
But here’s the cool thing about Taxus, and other plants belonging to the group of ‘mound-growing’ shrubs. (For more information on groups of shrubs — cane-growers, mound-growers, and tree-likes, see the writings of Cass Turnbull, the Seattle shrub pruning guru and founder of Plant Amnesty.) Mound growers have tons of dormant buds along their stems, and when foliage is cut from the plant, those buds break and cover it with fresh new foliage; the buds are stimulated to grow by this type of cutting.
The arborists (Hartney Greymont of Needham, MA, who know what they’re doing) knew this, and took what horticulturally was a very good approach to the work. The short-term aesthetics were a little alarming, but produced a great result, as you can see here from this 2009 photo. Three years of growth have given back the most of the hedge height, and have left it lush and dense with fresh growth.
The same hedge, now 5' high and thriving
Aftercare of this kind of work is essential, especially in the first year or two after the cut-back: the shrubs should be given enough water and some mild fertilizer, to help them recover from what they’ve just been through. If hand-pruning isn’t practical on a bigger hedge, it should be sheared with a slight batter (make the bottom wider than the top), and then gone over with hand pruners to loosen up the outside ‘wall’, so that light and free airflow can still reach into the plant’s interior.
As with the forsythia renovation, this is extreme pruning, to be done only when it’s the one solution short of removal and replanting. It can be done on the same plant or hedge once every 12-15 years, or even less frequently…
Deborah Howe
Toby Wolf
Whoa. So you mean I can do the same thing to the hedge outside our dining room? Can I send you pictures? It would make a huge difference in the way it looks if this kind of pruning would work for it!
Send photos, and let’s see. Taxus is an incredibly durable plant. Good exposure is helpful for this kind of renovation; the plants shown on this post are in full sun. One of the reasons Taxus is such a workhorse in the landscape is that it can handle quite a bit of shade, as well. I’m guessing that renovation would be OK in the shade, but recovery would take considerably longer than with more sun.
Another way that some people like to deal with an overgrown specimen yew is to leave its height, and take foliage off the thickest limbs, revealing the beautiful cinnamon-colored bark and underlying structure of the plant. The plant is left with cloudlike tufts of foliage at the clumped twigs. Can work, can look peculiar. You probably wouldn’t want to do this with an entire hedge (and might not be able to anyway, given how the hedges are typically pruned.)
In a lecture, Gary Koller – and I may have gotten this wrong – showed some examples of a two phase renovation of yews. In year one, you take one side of the plant (one side of the hedge) and cut it as low as you need, nearly down to the ground if you like. The shrub will survive this brutality because the other side is still up there photosynthesizing and respirating and all that good stuff. Then you come back in year two or year three, once the first pruned side has some good growth, and take down the other side. The second side soon catches up to the first, and you have an entire shrub of fresh new growth. That said, I’ve never done this myself and may have misinterpreted part of what Gary was saying, so don’t do it just because I say so.
And of course I wouldn’t do this to a shrub that has the kind of sculptural/structural potential that Deb describes in her comment above.
I’ve seen this method used on a long yew hedge, too, but have to say that it seemed less successful. Maybe the pruner took too much off the first side, or the aftercare was poor (seems unlikely in this instance), but two years after the first side was cut it was struggling, and so the client delayed having the other side cut.
On the hedge I showed, the arborists were supposed to remove the interior of the plants and leave the outside stems, so that the inside could grow back in relatively concealed privacy. The idea was then that the outside stems would be removed a year or two down the road, once the inside stems had rejuvenated.
As scary as the actual method used was, though, it worked best, I think. In the way that it’s a delight to see the bare stems of deciduous plants get dressed in the spring, it was a delight to see this hedge recover its form and foliage.
Actually, the same hedge I will be sending you pictures of was sticking way out over the patio when we first moved into the house. I boldly trimmed back one side – to my husband’s horror – because it was sticking out so far, and it is looking pretty good there now. I guess I’ll just need to remind him of this when I confront the whole hedge with this technique!
How would this work with a mugo pine?
If you have already cut back your yew and seen success with its recovery, then continuing should be ok, especially if it gets sufficient sunlight and moisture.
This technique is definitely not one to use on a mugo pine (Pinus mugo). Pines don’t have dormant buds under their bark, so if you cut back on a pine, you’ll wind up with a dead stub, and no new regrowth on that limb. Pines grow at the tips of their twigs, and to keep them somewhat in check you can pinch back the new candles of growth by one or two thirds before they put out actual needles. Otherwise, your pruning should be limited to taking off dead or broken branches, or possibly cutting a branch or two (but be careful, there may not be that many!) back to a main limb or trunk. If those techniques don’t do what you want them to do, you may simply have too big a plant for that spot.