Louis Raymond experiments in his own gardens like

a mad scientist, searching out plants that most people have

never seen before & figuring out how to make them perform.- The Boston Globe

…Louis Raymond ensures that trees can grow in Brooklyn…

or just about any other place where concrete consumes

the dirt and skyscrapers shield the sunshine.- USA Today

 
 

NEW Trips to Take!

Myrtle's easy when the conditions are right.

 
 
 
 

NEW Plants to Try!

Louis tries to capture the exact words to describe the fleeting but deep pleasures to be found in these Summer-into-Autumn incredibles.

 
 
 
 

New Gardening to Do!

Allergic to bees? You can still have an exciting garden, full of flowers and color and wildlife.

 
 
 
 

Plant Profiles

Today in the Garden of a Lifetime: Coat-racking the Hedge of American Holly

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American holly that grows free-range is, well, a bit static. Yes, it grows steadily. And it has great dignity. And, hey, it is the hardiest broadleaved evergreen tree. But it looks the same year-round.

 

By contrast, holly growing as a hedge is always in flux. Each year its outer branches get a thorough clipping to keep the hedge shapely and in bounds. And every decade or so, the hedge gets "coat-racked" by cutting branches and even major limbs to within inches of the trunk.

 

Year by year, those years of tip-pruning help keep the hedge's outer twigs and foliage thick and effective as screening. But not all of each year's growth is removed. Let a decade go by, and the holly plants that might have been three or four feet wide will have grown to six or eight feet wide.

 

A look into the center of my American holly hedge shows how wide it has become. With the espalier of lindens at one side of the hedge and the property line at the other, there's only so much room available. Tip-pruning is no longer the solution; coat-racking is. 

 

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To maintain a reasonable amount of the hedge's "screenage," I'll coat-rack just one face at a time. Ilex opaca naturally grows as a multi-trunked tree; all the branches that project towards the viewer in the picture below will be cut off. If any of the main trunks seem to be angling out too far, I'll saw them off, too.

 

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All forms of evergreen holly are terrific for hedges, in part, precisely because they tolerate coat-racking. Even if Rip Van Winkle bought my property, and the hedge wasn't pruned for many years, it could still be coat-racked and its narrow form recaptured. This is because new branches sprout eagerly from even the oldest holly wood. If this hedge were to be abandoned for generations, or limbed up but left to grow free-range higher up, the trees could be cut down to stumps with a chain saw and the stumps would resprout profusely. 

 

I just need to coat-rack. Compared to tip-pruning, it's a startlingly fast process. There could be scores of tips to prune, even hundreds—and because holly foliage would scar noticeably if individual leaves were partially cut in the process, their pruning needs to be done by hand, tip by tip. Those hundreds of tips connect to the holly's trunks by only ten or twenty branches. Coat-racking one face of a ten-foot holly tree takes only a couple of minutes.

 

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Five holly trees done, thirty to go. It's important to coat-rack the top face of the hedge, too, not just this first side. (I'll cut off the top when I've finished with this side.) The tips of plants produce a hormone that helps inhibit the growth of tips lower down. This makes sense when the plant is, say, a tree: The top tips are most likely to receive the most direct sun, and for the longest time each day. The higher they grow, the more sun they'll continue to receive, and the better the plant will do overall.

 

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But the definition of a hedge is thickness of growth on its two faces. And the gold standard of a great hedge is the thickness of that growth at the very bottom of those faces. Cutting off the top of the hedge ensures that the the great majority of the production of growth-inhibiting hormone is now stopped.

 

Yes, if the other face of the hedge were also coat-racked at the same time, the production of growth-inhibiting hormone would be stopped almost entirely. But that helpful cessation would be achieved at the expense of all of the hedge's ability to screen for the next six months and more. Coat-racked holly resprouts vigorously, but my trees are planted about six feet apart. If they were fully coat-racked in one frenzy of pruning, the hedge would be reduced to a series of trunks with shorty stubby limbs. It would look like a tail-gate sale of coat-racks. 

 

I'll coat-rack this face and the top of my hedge this Winter, and the other face a year from now. By that time, this face will have resprouted reasonably, and the hedge's ability to screen will be maintained.

 

There's yet another dimension (so to speak) to this first round of coat-racking. Removing the top as well as the face allows the maximum amount of sun to reach the hedge's cut face from top to bottom. This is especially true in my garden, where the line of the espaliered linden is fewer than eight feet from the line of holly trunks. The wider the aisle between the two, the more sun for both.

 

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Coat-racking should be done in preparation for holly's major growing season: Spring. That's a window from late Fall to late Winter. Prune when you've got the yen and the weather is with you; coat-racking would be awkward or even dangerous if you attempted it when there was a foot or two of snow on the ground. Where I garden, the worst snows are often in March, at the end of the "coat-racking season." It's better to get the job done earlier, when the opportunity first presents. 

 

Coat-racking yields an amazing volume of cut branches. There will be a mound of them to dispose of. A berm, even. Given that coat-racking is, in this sense, removing the entire side of the hedge and throwing it onto the adjacent pathway, such a mountain of cut branches would be no surprise. Coat-racking is reason enough to be sure that there is an adjacent pathway to your holly hedge, instead of a bed of perennials or other shrubs. 

 

"Disposal" doesn't mean trundling to the brush pile. The cut branches will hold their thick rigid leaves through the Winter, and are terrific for protecting less hardy plants. In effect, they act as a mulch where each piece of mulch—each leaf—is individually attached to a framework—the branches. This ensures that the pieces stay in place and yet also keep open the plentiful gaps between them. Those gaps are full of air, which, when held fairly still, is the best insulator of all. Laid-on thickly, cut branches of holly are better winter protection even than sheets of bubble wrap, because some flow-through ventilation is still preserved.

 

In my gardens, the holly branches will be mounded snugly over and around younger crape myrtles and osmanthus, and especially the "hardy" palms that are, just now, experiencing their first Winter. Next Winter, the second face of the hedge will be coat-racked, so I'll be set for "bubble wrap" that season, too. After that, those palms should be big enough to be hardy—or not. Or perhaps there's yet some other holly on the property that will be ready for its coat-racking debut.

 

Here's how to grow a yellow-berried form of American holly.  No matter what the berry color, all American holly cultivars want similar treatment.  Here's a look at American holly that's been growing free-range for decades.

 

 
 
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