It is no wonder that it takes many years to get to fifteen feet tall, and may never get more than twenty feet tall. Weeping bottlebrush, Callistemon viminalis, may grow less than a foot a year, but seems to hang downward two feet. Because the stems are sculptural, and the bark has an appealingly rough texture, most weeping bottlebrush trees are grown with multiple trunks. The brick red bottlebrush flowers that bloom sporadically at any time of the year are more abundant early in summer. Established plants bloom more colorfully with a bit of water, but can probably survive quite a while without it. The evergreen leaves are narrow and mostly less than three inches long. Weeping bottlebrush needs good sun exposure.
Even without the bright yellow staminate flowers (fuzzy with prominent stamens) that bloom in late summer or autumn, the grayish foliage of knife-leaf wattle, Acacia cultriformis, is still striking. It contrasts nicely with dark green foliage of pines, redwood and ivy. What seems to be small triangular leaves are actually ‘phyllodes’, which are modified petioles (leaf stalks) of vestigial leaves. They are about half an inch to an inch long, and neatly arranged on stiff stems.
Mature trees do not get much more than ten feet tall, and grow slowly enough to be kept even shorter. They can tolerate a bit of shade from larger trees. However, they bloom more profusely with better exposure. If the pollen is not a problem, the flowers are nice for cutting. So is the foliage, which is complimentary to many other cut flowers. Like almost all acacias, knife-leaf acacia does not require much water once established.
Ah, something vintage! Remember Hollywood juniper, Juniperus chinensis ‘Kaizuka’ (or ‘Torulosa’) flanking big two-car garage doors of mid century modern homes? Those that are still around after half a century are big and strikingly sculptural, like miniature Monterey cypress for home gardens. They get about fifteen feet tall and ten feet wide, but have potential to get significantly larger.
Hollywood juniper is an old classic that is still reasonably available in some nurseries. Their densely foliated stems twist and turn picturesquely upward, typically leaning one way or another toward sunlight or away from prevailing wind. Some say they look like frozen green flames. Their gnarly trunks and flaking bark can be exposed as they grow tall enough for low growth to be pruned away.
Because of their very irregular branch structure, Hollywood juniper is more adaptable to free-formed pruning than the presently trendy junipers with strictly upright or conical form. They must never be shorn, but do not mind if obtrusive limbs get pruned back to the main trunks. Therefore, they are actually more adaptable to smaller modern gardens than some modern cultivars of juniper are.
In California, it is hard to imagine that hinoki cypress, Chamaecyparis obtusa, gets big enough to be harvested for lumber in Japan. Almost all of the local garden varieties stay quite short. The largest rarely get up to second story eaves. The most compact types that are grown for bonsai, do not get much more than a few inches tall. Most are somewhere in between, to about ten feet tall.
The ruffled sprays of evergreen foliage are surprisingly dense relative to the soft texture and often irregularly loose branch structure. Mature trees often shed branches to reveal sculptural reddish trunks and limbs within, while maintaining the distinct density of their foliar tufts. The minute leaf scales have rounded tips. (Other specie have pointed leaves.) Tiny round cones are rarely seen.
Because of slow growth and irregular form, hinoki cypress is an excellent specimen ‘trophy’ tree, but not so useful as hedging shrubbery. It prefers a bit of shade, and will tolerate considerable shade. However, varieties with yellow new growth are more colorful with good (but not harsh) exposure. It does not take much pruning and grooming to enhance form and expose branch structure.
‘Shrubbery’ sounds so unflattering for a pine; but mugo pine, Pinus mugo, is not really much of a tree. The tallest trees do not reach eaves. Most old trees are only a few feet tall and about twice as broad, with strictly rounded form, and dense forest green foliage. The stout paired needles are only about one or two inches long. The plump cones, which are rarely seen, are not much longer.
Although very rare in other types of landscapes, and originally from the Austrian and Italian Alps, mugo pine is one of the most popular and traditional features in Japanese gardens. Even though it grows very slowly, it should have enough room to do so without competing with other more aggressive plants that might overwhelm it. It should neither be shorn nor pruned back too aggressively.
It does not grow fast, but by the time it gets old, mayten, Maytenus boaria, might be tall enough to reach upstairs eaves, and nearly as broad. The main trunk and limbs are nicely outfitted with uniformly checked grayish bark. Smaller stems are so very limber that it is a wonder that trees are able to gain any height at all. These stems arch gracefully, with their wiry tips hanging vertically.
Almost all modern maytens are of the cultivar ‘Green Showers’, which has slightly larger leaves. Yet, the evergreen leaves are so small that it is not easy to discern much difference from the slightly yellower leaves of older trees. Ironically, older trees seem to be more resilient. Newer trees seem to be more sensitive to rot if watered too frequently, particularly if soil does not drain adequately.
Pruning and grooming is not as simple as it might seem to be from the outside. If the very pendulous stems around the edges get cut like bangs, bunched stems accumulate and lose their softly pendulous texture. They need to be thinned too, so that they can hang more softly. Dead stems should be groomed from within. Main stems are not likely to regenerate if cut back too severely.
No, it is not an oxymoron. ‘Yellowwood’ is the common name for a few specie of Podocarpus. The evergreen (or ‘everblue’) foliage of ‘Icee Blue’ yellowwood, Podocarpus elongatus ‘Monmal’, really is as silvery grayish blue as the name implies. It can be as striking as some cultivars of Colorado blue spruce. It grows slowly in narrow columnar form to only about fifteen or twenty feet tall.
The finely textured evergreen foliage is ideal for both formal hedges and informal screens, although it takes a while to fill in, particularly for larger hedges and screens. Tip pruning of lanky growth of informal screens improves density. The narrow leaves are about two inches long. Fresh new foliage may be lighter and very slightly greener, which can contrast nicely with more mature foliage.
‘Icee Blue’ yellowwood will tolerate a bit of partial shade, but exhibits the best color in full sun. It prefers to be watered somewhat regularly while getting established. As it matures, it becomes less reliant on watering. Like many other Podocarpus, it is susceptible to infestation by scale insects and the ants that cultivate them. Scale produce sticky honeydew which blackens with sooty mold.
The first half of the name sound appealing enough. The second half, not so much. Do the seeds grow into snails? Do they just look like snails? Not many have seen them. Tiny pale white flowers that are supposed to bloom in spring, as well as small black berries that develop after bloom, are rare. Laurel-leaf snailseed, Cocculus laurifolius, is grown just for its glossy evergreen foliage.
The foliage superficially resembles that of common privets. Upon closer inspection, the leaves are somewhat elongated, and outfitted with distinct marginal veins flanking the midveins. As stems that become heavy with lush foliage lean over, vigorously vertical stems fill in the space, until they too arch over as they become fluffy with foliage. Mature trees might get twenty feet high and wide.
Because of its complaisant roots and tolerance of partial shade, laurel-leaf snailseed is popularly installed as a foundation plant (at the foundation of a home) but then obscures windows as it gets too big and awkward. Its arching branch structured does not do well with formal shearing. It works much better as an informal screen in the background, or as small tree with multiple trunks.
Those of us with ‘maintenance gardeners’ are likely aware of how rare it is to find someone who knows how to maintain hedges properly. It seemed so simple years ago. Several identical plants could simply be planted in a row, and then somewhat regularly shorn for confinement to a prescribed space. They were not allowed to exceed a specific height or width for long between shearing.
Formal hedges are now passe. They do not conform to modern landscape style. No one wants to maintain their formality anyway. If a gap develops, it is likely to be filled with a different cultivar or species that is not identical to the rest of the hedge, merely because it happened to be available at the nursery. Feral or invading shrubs, vines or even trees get shorn right into the whole mess.
Then there is the problem with bloat. Rather than staying confined, hedges typically get slightly larger with each shearing. What is worst is that most of the extra bulk is high up and shading lower growth, causing it to grow slower. Hedges eventually develop that all too familiar top-heavy appearance, and encroach into otherwise usable space that they were designed to provide privacy for.
There are few simple options for hedges and shorn shrubbery that have gotten too big for their space. Some can be renovated and cut back beyond their outer surfaces, but recovery will take a bit of time, and can not fix unmatched plants. However, such restoration is likely better than replacement. Just like for a new hedge, feral and invading vegetation must be removed in the process.
Another option is to completely change the form of improperly shorn shrubbery to small trees. This can be done with individual shrubs, or a few selected remnants of an otherwise removed hedge. Cherry laurel, photinia, bottlebrush, tea tree, privet, various pittosporums and many other large hedge shrubs work quite nicely. Rather than getting pruned back into submission, the lower growth gets pruned away to expose sculptural trunks within, and the upper growth gets pruned only for clearance above.
My weekly gardening column does not have much space for everything that should be said about the various topics and featured specie. I just try to fit the most basic of information into the space available, but usually would like to fit more in.
Sometimes, I would like to fit more pictures in too. It can be difficult to select just one camellia, or just one rhododendron. I typically select those that have the best contrast for black and white pictures, just in case some newspapers must deprive them of their color. That often means that I get to select my favorite white flowers rather than their more colorful counterparts. Regardless, there are so many good pictures that do not get seen. Then, there are also many qualities of the subjects that are difficult or impossible to show in pictures.
The dogwood picture that will get posted on Tuesday is pretty good, and happens to be white, but does not show how spectacular the tree that produced the bloom is. I selected a picture that was a close up of the same flowers in the picture below. Unfortunately, even if I had room for another picture, I could not get one that adequately represented the splendor of the tree. The best I could get is the picture above. I might try to get more pictures of pink and red dogwoods in the next few days, but pictures are nothing like the real thing. I had the same difficulty with the flowering cherries. The bloom was spectacular close up, but the trees looked like pink clouds on trunks from a distance.
If you can imagine, the tree in the picture is about twenty feet tall. It can be seen half a block away, through the adjacent deciduous trees. It looks just like a dogwood in Virginia should look, but happens to be right here on the West Coast, where you would not expect to see such an excellent specimen. Does that help?
I used to grow dogwood trees in the mid 1990s. They are not my favorite spring flowering tree because they do not do so well in the Santa Clara Valley. You would not know that by how well they do here on the coastal side of the Santa Cruz Mountains, just a few miles away. There are many specimens in the neighborhood that are comparable to this one. Some are pink. A few are almost brick red. The foliage probably does not color as well in autumn as it would in Virginia, but by our standards, it colors nicely.
Two very happy pink dogwoods are in front of an elegant home of early American architecture that is located just downhill from the white dogwood in the picture above. Even with redwoods and coast live oaks all around, the dogwood trees and home really look like they could be in the vicinity of Virginia. It is obvious why those from the East are so fond of dogwoods.