Photinia

60316As a shorn evergreen hedge or simple shorn shrubbery, photinia, Photinia X fraseri, produces handsomely glossy bronzy red foliage without bloom. It is best if shorn as weather warms at the end of winter, and then allowed to grow out for a while. It can be shorn again through summer as bronzy foliage fades to green, but should not be shorn so often that it is always deprived of red foliage.

Without regular shearing, photinia becomes a small tree or large shrub. Trees can either be staked on single trunks, or allowed to develop multiple trunks. New growth in spring is not as vigorous as it would be in response to shearing, so is not as colorful. Domed trusses of tiny white flowers bloom about as soon as new foliage appears. The floral fragrance can be objectionable to some.

Only the biggest and oldest trees reach high voltage cables. Most stay less than fifteen feet tall and broad. Hedges can be kept less than six feet tall, and ideally, should be kept less than half as deep (from front to back). Photinia can grow rather well while young, but then grows slower as it matures. Partial shade or a lack of water through summer compromise foliar color and density.

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Pruning Late Might Be Justified

90313thumbThere may not be exceptions to every rule, but there are a few exceptions to the rule that winter is the best time for pruning. It is generally true that most plants are the most dormant through the coolest part of winter. It is also true that while they are the most dormant, most plants are less sensitive to pruning, as well as other horticultural techniques that interfere with their normal function.

However, certain ‘special’ plants get pruned later, either because it is healthier for them, or just because they are allowed to do what they do best in spring before getting deprived of some of what they need to do it with. Some get pruned rather soon after coming out of winter dormancy. Some should probably wait for their new spring growth to mature a bit. It is not as confusing as it sounds.

Evergreen plants that drop much of their older foliage through winter should probably be pruned late in winter or early in spring, essentially at the last minute, just before new foliage develops. If shorn early and deprived of outer foliage that should survive through winter, photinia looks scraggly as it continues to lose much of what had been inner foliage until new foliage develops in spring.

Red twig dogwood and some types of willows that are coppiced or pollarded to maximize production of their colorful twigs should be allowed to show off their colorful bark for as long as possible. Like photinia, they too can be pruned at the last minute, just before vascular activity resumes. However, red twig Japanese maple really should be pruned in winter so it does not bleed afterward.

Flowering cherry, plum, peach, crabapple and quince are grown for prolific but sterile bloom which is diminished by winter pruning. If they need it, they can instead be pruned after bloom, but before too much foliage develops, or after such foliage matures in late spring or early summer. They do not need to be pruned nearly as aggressively as fruiting trees that would otherwise produce too much burdensome fruit. Some may only need to have dead stems pruned out.

Bullwinkle II

P90303What makes this Bullwinkle worse than most is that I pruned it like this myself. What makes it worse than worse is that it did not need to be pruned in this disfiguring manner for clearance from utility cables like the last one I wrote about was. https://tonytomeo.com/2018/08/08/horridculture-bullwinkle/ It is instead an attempt to renovate an overgrown hedge that was behaving something like a fat hedge. https://tonytomeo.com/2018/06/06/horridculture-fat-hedges/

In fact, the only reason it did not qualify as a fat hedge is that it had plenty of space for all of its superfluous bulk The side to the left was only beginning to encroach into the driveway on that side, and was easily pruned back to the curb, which for now, is adequate confinement. The side on the right was only beginning to encroach into the upstairs balconies, and was likewise easily pruned back for reasonable clearance.

The problems with this hedge were within and on top. It had been shorn back only for minimal confinement for so long that all the foliage on the sides was within a thin external layer. Pruning any farther back would have exposed a thicket of necrotic stems in various degrees of deterioration that had been accumulating within the interior for many years. Almost all growth was directed to and concentrated on top, which shaded the interior and lower stems even more than the accumulation of necrotic crud within did. Since the top had always been pruned down to the same height, all subsequent growth after pruning on top was above where it had been pruned previously, which was of course above the height where it was wanted, and consequently removed when the hedge was pruned again. There was no incentive for lower foliage to develop.

The hedge is there to obscure the view of a building on the left from the windows of the building on the right. The most important foliage for that purpose is the lower foliage, which is precisely what is lacking. Almost all resources were going to the upper foliage, which was contributing nothing, while shading out the lower growth. Although the inner thicket of necrotic stems was partially helping to obscure the unwanted view, it was also inhibiting healthier lower growth.

The illustration shows what remains after the useless top and necrotic interior were removed. After the picture was taken, the left and right sides of the hedge were pruned lower to eliminate the useless upper foliage that was not contributing to the function of the hedge. As unsightly as it is, it partially obscures the view of the building on the left from the building on the right, and will obscure it more as new foliage develops. Now that the interior is exposed, new growth should develop within the interior, and lower to the ground. Because the area is partially shaded by nearby redwoods, the exposed interior limbs are not likely to be damaged by sun scald.

After the new interior growth is established and obscuring the view, the external sides that are there now can be pruned back farther and sloped inward toward the top so that the lower growth of the hedge gets more sunlight. The hedge certainly does not need to be as wide as it is. It would be easier to maintain if it were narrower and so close to the allowable boundaries. Ultimately, with appropriate pruning over the next few years, this old hedge should be restored.

English Boxwood

90306While 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.

Horridculture – Instant Hedge

P90220Back when horticulture was still respected, a very long time ago, dense shrubbery with finely textured foliage, such as Japanese boxwood, could be purchased already shorn into cubes that only needed to be installed in a closely set row to become an ‘instant hedge’. For some small hedges composed of small plants that recovered efficiently from transplant, it actually worked reasonably well, even if they did not look so great at first. It also worked for a few larger shrubs that happened to transplant very easily, such as glossy privet. Tall arborvitaes happen to work exceptionally well as instant hedges, although the best spacing for them leaves temporary gaps in between.
However, most of the best of the bigger shrubbery should not be planted as instant hedges. The taller specie of Pittosporum get too distressed from transplants when mature, so should instead be planted while small, and allowed to grow into a hedge. Larger and much more expensive shrubs, take a few years to recover from transplant, and some recover much slower than others, compromising the conformity of the hedge as it develops.
That being said, I am not certain what to say about this instant hedge. The individual plants are much too close to each other, probably because someone wanted instant coverage, but perhaps because the so-called ‘gardener’ could charge more for installing more plants. I seriously doubt that the so-called ‘gardener’ will be able to contain these junipers, which will want to get much taller and wider than their confined space will allow. Even if the hedge bulks out just a slight bit beyond the curb, it will shade out the lower foliage more than it already is. I actually expect the junipers to grow well out into the driveway within only a few years, as they compete for space. If they get big enough, they can break the curb and asphalt pavement. It annoys me mostly because I like Skyrocket juniper so much, that I hate to see it abused like this.
Yet, It could work. As unlikely as it seems, there is a very slight possibility that the so-called ‘gardeners’ may be more qualified than I give them credit for. (Or they might be replaces with such. This is after all, the backside of the same landscape that is inhabited by the crepe myrtle featured last Wednesday.) After all, someone seemed to have enough sense to select #5 (5 gallon) plants instead of #15 (15 gallon) plants that would not be doing so well now. If the top of the hedge is kept down to prevent the junipers from growing as trees, and the facade of the hedge is kept contained to within about a foot and half of the wall behind it, lower growth will regenerate and get enough sunlight to not get shaded out. It will take serious commitment, and a specialized combination of regular shearing and selective pruning to limit congestion, but this hedge just might work.

Guilt Trip

P80923It 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.P80923+

Horridculture – Neapolitan

P80801Baldness 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.

Horridculture – Fat Hedges

P80606

This is the first article within the designated ‘rant’ format, that will continue each Wednesday. Articles for the other six days of the week will be more cheerful, or at least less objectionable. These articles may not always be rants, so might alternatively include discussions of particular fad, trends, gimmicks and so on. Perhaps some topics will remain just that; discussions in which the advantages and disadvantages of a particular subject are compared. Categories may develop, so besides ‘Horriduclture’, there could be a category for discussions of fads, for example. This is a new format for me, so I will keep it open to modification, and see how it goes.

Fat hedges are one of my serious peeves!

Hedges done properly are very useful landscape features, that provide privacy, obscure undesirable views, muffle outside sound or simply divide a large garden space into smaller garden rooms. Landscape designers know how to use them, and are good at planning their locations and orientations, as well as designating the plant material to be used for particular hedges. Some informal hedges or screens are outside of useful space, where they have plenty of room to grow plump and wild without becoming obtrusive. Formal hedges are those that require shearing for confinement within limited space.

Fat hedges are those that are designed to be contained, typically by formal shearing, but are instead allowed to encroach into the usable space within the landscape that they are designed to enclose. They can be a serious problem in confined garden space, and sometimes occupy most of the space themselves.

Seriously, they are very often several feet deep (from front to rear). Fat hedges on either side of a small garden room that is only about twelve feet wide can easily occupy more than half of the area. Think about it. If each hedge is just three feet deep, and there are two hedges, that means that six feet of the width of the twelve foot wide space is occupied by fat hedge! That is half of the area available! Some fat hedges are even deeper! A fat hedge does nothing more than a properly maintained hedge. Really, a three foot hedge accomplishes no more than the same sort of hedge that is only one foot deep. The interior is only bare twigs.

Fat hedges are mostly the result of inept gardeners who allow the hedges to gain a bit more width with each shearing, without ever renovating overgrown hedges. To make matters worse, they allow the tops of the hedges to get wider, which shades out lower foliage, which becomes sparse. Then the fat hedge becomes a top heavy hedge, leaning into usable space where it should be leaning slightly away. Ends of top heavy hedges often protrude a bit more than the sides of the hedges. If these hedges flank a driveway or walkway that is perpendicular to the sidewalk or a patio, the distended end is particularly obnoxious.

In the picture above, the low hedge seems to be well maintained. If it is a fat hedge, it is in a situation where it is not really crowding much. However, notice the width of the sidewalk. It is quite broad. Then there is a significant constriction where the hedge protrudes over the sidewalk. What is the point of so much concrete and such a wide sidewalk if almost a quarter of the width of it is overwhelmed by vegetation? It is like four lanes of freeway that merge into three, only to merge back into four.

Cherry Laurel

80530There 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.)

Wax Privet

70517The 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.