Good old fashioned boxwood hedges really look silly if just a single missing plant get replaced with a different cultivar (cultivated variety) or specie. Most of the older boxwood hedges are the traditional, but somewhat yellowish Japanese boxwood. Most middle aged hedges are a relatively newer cultivar that is a bit greener. Modern boxwood hedges are more likely a cultivar of English boxwood, Buxus sempervirens.
English boxwood resembles Japanese boxwood, but has slightly narrower leaves that produce a slightly more objectionable aroma when shorn or otherwise disturbed. These opposite (paired) glossy leaves are only about a quarter to half an inch wide and about twice as long. The color is slightly darker with a more ‘olive’ tone. Wild English boxwood in Europe can grow as small trees. Most garden varieties are fortunately much shorter and more compact, which is why they are so popularly shorn into small formal hedges. They also do well as topiary. ‘Aureo Variegata’ is variegated with nicely contrasting cream colored leaf margins.
Victorian landscapes made good use of cherry laurel, Prunus laurocerasus. It works well as a large formal hedge. For more relaxed modern landscapes, it makes delightful informal screen. The main reason that it is now less popular than other hedging shrubbery is that it gets rather broad if not shorn back regularly. If allowed to grow as a low rounded tree, it can get twenty-five feet high!
Regularly shearing is not necessarily frequent. It should be efficient though. Confinement for such broad shrubbery is important. If shorn back farther than where the outer surface is desired late in winter, fresh new foliage can fluff out nicely within allowable space through spring. Subsequent aggressive shearing to maintain confinement may only be necessary once or twice during summer.
The big leaves are about three inches long, and luxuriantly glossy. If hedges get shorn less aggressively, but more frequently than two or three times annually, such big leaves can be rather shabby much of the time. If shorn less frequently, small trusses of creamy white flowers may get a chance to bloom. Cultivars are more compact than the species. One cultivar is variegated with pale gold.
‘Six on Saturday’ is a weekly tradition for many of us who enjoy sharing six horticulturally oriented pictures on Saturday. I just did it earlier this morning.
This is not ‘Six on Saturday’. It is just one picture of six arborvitae. What’s worse is that there is an indistinguishable seventh at the far end of the row. It blends into the sixth in this picture. There are seven barberry between them, with the seventh beyond the last arborvitae. This picture was taken more than a week ago, so most of the amaryllis are done blooming now.
This row of arborvitae and barberry was installed early last winter, after a grungy hedge of photinia was removed. It would have been nice to salvage the photinia, but they were such a mess that the process would have taken more than two years, and even then, would have been patchy.
These arborvitaes will not grow into a contiguous hedge like the photinia were, but already soften the otherwise uninviting visual impact of the plain and uniform fence behind. They will grow taller and broader, but will never get so big that they will be difficult to maintain. It should be easy enough to get behind them to prune away parts that get too close to the fence.
I happen to be pleased that we were able to incorporate this sort of formality into an otherwise completely informal landscape. The irregularity of the terrain, as well as the randomness of the big forest trees that were here before landscapes were installed, make such formality nearly impossible. Even if it were easier, formality is not exactly fashionable in landscape design.
Despite their imposed formality and exotic origins, both the arborvitae and the barberry are remarkably compatible with the native flora of the surrounding forest landscape.
While flashier but typically weaker modern cultivars of so many other specie are being developed, the most popular of the many cultivars of English boxwood, Buxus sempervirens, remain the same. There is not much to improve on. Most cultivars get only a few feet tall, and are densely foliated with inch long evergreen leaves that are excellent for topiary and low formally shorn hedges.
One of the difficulties with formal hedges, or any formal application, is replacement of any specimens that die. There are not very many of the different cultivars available locally; but it can be quite difficult to distinguish between some of them. One specimen of the wrong cultivar ruins conformity! Another concern is that the aroma of the foliage when disturbed may be objectionable to some.
In the wild, English boxwood grows as small trees or rather larger shrubs with relatively open structure. Locally, such specimens are only very rarely found in old Victorian landscapes, such as at the Winchester House. ‘Suffruticosa’ is so compact that it popularly allowed to grow as as unshorn and nearly spherical shrubs. ‘Argenteo-Variegata’, ‘Variegata’ and ‘Marginata’ are variegated.
Just like real rosemary, the coast rosemary can either be a low ground cover or a dense shrub. Lower cultivars can get nearly five feet wide without getting much more than a foot high. Shrubby types can get nearly six feet tall without getting much wider. Shrubby types are more popular than ground cover types, and are often pruned so that they do not get too broad.
The tiny leaves of coast rosemary are silvery or grayish green, and can be variegated. Small white or very pale lavender flowers bloom sporadically throughout the year, and can be profuse in spring. Established plants do not need much water, but are probably happiest if watered somewhat regularly through summer. Shade subdues silvery foliar color and inhibits bloom.
Shrubby coast rosemary makes a delightful low hedge. It can be shorn like any other formal hedge, but is best where it has space to develop naturally. If space is limited, but not ‘too’ limited, a coast rosemary hedge can be aggressively shorn once annually at the end of winter, and then allowed to grow wild for the rest of the year.
It was so long ago that I barely remember it. I was just a little tyke. My older sister tripped on the driveway and broke one of the Japanese boxwood shrubs in the hedge on the edge of the driveway and front walkway. The hedge was still young then, and not completely filled in. My Pa replaced the missing shrub shortly afterward, but not before my younger brother and I learned that the gap was a shortcut through the hedge. The puny new shrub was not enough to compel us to go around like we had done before. Of course, it did not survive for long. It too got broken off.
We did feel sort of guilty, but only for a while. The second shrub was replaced with a third, which seemed like it should be sufficient to patch the gap in the otherwise formally shorn hedge. We were careful with this one, and actually got into the habit of going around the hedge to avoid altercation with it. However, it died even without our influence. Again, we felt guilty about the g. ap.
I do not remember if there were more attempts to fill the gap in the hedge with other shrubs. When we moved away from that house, the shrubs on either side were slowly filling in to obscure the void. A few years later, the gap could not be seen.
However, many years later, the hedge was pruned with an up-do, which exposed the lower few inches of trunk of each of the individual shrubs. Although there was no gap in the very uniform hedge, it was very obvious that one of the trunks was lacking, right where it had always been lacking. Oh, the guilt!
Even if someone wanted to go through the effort to cut a hole in the otherwise exemplary hedge to replace the missing shrub, it would be very difficult or impossible to find a shrub of that now old fashioned cultivar of Japanese boxwood. Modern cultivars are darker green. A single shrub of a modern cultivar would only compromise the uniformity of the now very uniform hedge. The missing shrub will need to stay missing forever. More guilt on top of guilt!
The satellite image below and the street level view from Google Maps shows that the hedge is now foliated all the way down the the ground. I will not even bother mentioning where the the missing shrub is missing from. I know you could not see it anyway. The hedge is a bit more overgrown than I can remember it ever being before, and it has a bit of that fat hedge syndrome going on, but it still looks great for half a century old. The gap is long gone. Only the guilt remains.
Baldness was not yet cool while Brent and I were studying horticulture at Cal Poly in San Luis Obispo back in the late 1980s. Nor were hairpieces yet tacky. Consequently, some middle aged men work toupees. As these men aged and grayed, their formerly well matched topees did not.
Hedges of Pittosporum tobira ‘Variegata’ are notorious for developing green sports (unvariegated mutant growth). https://tonytomeo.com/2018/07/04/horridculture-mutants/ Because gardeners do not prune these sports out, they become prominent green blotches in otherwise nicely variegated hedges. Pruning large blotches out would only leave big bald spots. That is why such hedges, as well as similarly blotched hedges of other variegated plants, are known as ‘bad toupee’ hedges.
‘Neapolitan’ hedges are a variant of that concept. They are not composed of formerly identical plants that later challenged their respective identities. ‘Neapolitan’ hedges are actually composed of different plant material that has been shorn together. They sometimes develop as feral plants grow up and into formerly uniform hedges. They are often composed of what should have been distinct plants within a well designed landscape, that were merely shorn collectively by ‘gardeners’ who simply did not care.
This hedge in a median of a driveway into a mall in town is a classic example of the latter. The landscape designer likely intended the deep green Burford holly, Ilex cornuta, to develop naturally as dense and low mounds between the more upright variegated holly olive, Osmanthus heterophyllus ‘Variegatus’. Apparently, it is too much to expect a well paid ‘gardener’ to figure that out. Fortunately, this particular ‘Neapolitan’ hedge happens to look good in this particular application, but would look better if the ‘gardener’ would replace the variegated holly olive that has been missing for years from the gap between two Burford hollies to the left.
There is a reason why the most popular specie for frequently shorn formal hedges have small leaves and finely textured foliage. Technically, a formal hedge of cherry laurel, Prunus laurocerasus, can be shorn as well, but should be shorn only once or twice annually, and then allowed to fluff back out. Otherwise, the big leaves get shredded as quickly as they recover from previous shearing.
If pruned more frequently, hand pruning works best, and is not as tedious as it sounds. Informal pruning is even easier, and is done primarily to prevent hedges from getting to deep (from front to back), and to prevent individual shrubs from dominating or subordinating. Pruning also eliminates most of the abundant summer bloom of upright trusses of thirty or so tiny creamy white flowers.
Cherry laurel is densely foliated and quite stout, even without shearing or pruning, and can eventually but rarely get thirty feet tall! The glossy evergreen leaves are about three inches long. There happens to be a few cultivars, including one that is variegated with light yellow, and others that are compact dwarfs. (Prunus caroliniana is different species that is also known as cherry laurel.)
The pros and cons of wax privet, Ligustrum japonicum ‘Texanum’ might get it a rating of about 2.5 out of 5. It seems that every asset is offset by a liability. The profuse clusters of tiny white flowers are sweetly fragrant, but are also a serious problem for those allergic to pollen. The berries attract birds, but are also very messy, and contain seeds that can germinate in the strangest of places.
The dense evergreen foliage is prettier and actually glossier than that of the more common glossy privet. Growth is slower, and therefore easier to maintain as a shorn hedge. Regular shearing deprives wax privet of most, but not all of its bloom and seed. Glossy privet is more invasive if allowed to set seed, but less invasive as a shorn hedge deprived of bloom before producing seed. Without shearing, wax privet eventually reaches ground floor eaves, and gets about half as broad. It can be groomed into a small tree.
Unwanted feral seedlings should be pulled as soon as they are detected. If cut instead of pulled, they are likely to regenerate, and will be impossible to pull the second time around. Roots are rather greedy.
Hedges are a complicated topic! Like lawns, they are among the more functional features of a landscape. They can be used to provide privacy within, obscure unwanted views beyond, or merely to separate a large landscape into cozier or more functional spaces. Except for hedges that are grown for spring flowers or autumn color, most hedges are evergreen with finely textured foliage.
Informal screens, which might also be know simply as informal hedges, can function like hedges, but are a bit different. They are not regularly shorn, so do not need such finely textured foliage. They are either compact plants that stay proportionate to their particular situations, or are grown outside of a refined landscape, where they have plenty of space to grow wild to their natural size.
Although they do the work of fences and walls, hedges do not substitute for them. Fences are relatively ‘low maintenance’. Hedges are quite ‘high maintenance’. They need everything that other plants need, as well as dutiful shearing. Espaliers, trellised vines or vines clinging to fences or walls are also very different, with their own intense maintenance requirements and innate problems.
Most hedges were shorn late last summer or early autumn, but have not done much since then. They should have been shorn early enough for new growth to toughen up a bit to not look shabby or sparse through winter. Now that hedges are growing again, they will need to be shorn again. If space allows, shearing of photinia hedges can be delayed until the red new foliage fades to green.
While hedges get shorn, any volunteer plants that have self sown into them must be removed. Different species of shrubs or vines that sneak in will ruin the symmetry. This is also very important when adding new shrubs to replace any that might be missing. Even different cultivars of the same species will exhibit different color and growth rates. The sides of hedges should be sloped slightly inward at the top to allow more sunlight to reach the bottom, and to compensate for faster upper growth.