Its name says it all. Firethorn, Pyracantha coccinea, produces an abundance of fiery red berries on unavoidably thorny stems. A few old fashioned cultivars produce equally fiery orange berries. Cultivars with fiery yellow berries are now rare. Berries ripen for autumn, in time to feed migratory birds. Late berries can last longer after migratory birds are gone.
The rigid and wickedly thorny stems of firethorn work well as impenetrable hedges. They are rather difficult to prune and handle without impalement though. Unfortunately, simple shearing deprives formal hedges of some of their new growth that blooms and fruits most abundantly. Selective pruning is tedious and more hazardous, but might enhance bloom.
Shrubby cultivars of firethorn can grow higher than first floor eaves. Mature and vigorous hedges with hefty interior trunks at such height can generate spirelike growth that almost reaches second floor eaves. With pruning, some cultivars that sprawl close to the ground can stay quite low. Without pruning, some slowly form thickets that are several feet deep.
Since it is native to coastal chaparral between Monterey and the middle of the Baja California Peninsula, holly leaf cherry, Prunus ilicifolia, is right at home in local gardens of the central and south coasts. Although it can be a nice refined hedge if not shorn too frequently, it is better where it has space to grow wild into a mounding shrub, and can eventually grow into an undemanding informal screen as high and broad as fifteen feet. Width is easier to limit with selective pruning than with shearing. Besides, unshorn plants bloom with clusters of minute white flowers in spring, and produce interesting deep red or purplish red cherries in autumn. Unfortunately, the cherries have very big pits with only minimal sweet pulp. The small glossy leaves have somewhat bristly teeth almost like those of some hollies.
Hollywood juniper had formerly been the only popular juniper of tree form. As it became less popular during the past few decades, cultivars of the once obscure Rocky Mountain juniper, Juniperus scopulorum, became more popular. Also, a few more modern cultivars became available. Now, the once overly common Hollywood juniper is quite uncommon.
Rocky Mountain juniper is naturally rather grayish for protection from the harsh exposure of the high elevations which it inhabits. Cultivars are grayer, bluish or silvery, and mostly develop symmetrically conical form. Old specimens that were initially conical eventually grow as small trees with rounded and relatively dense canopies, perhaps on bare trunks.
‘Skyrocket’ and ‘Blue Arrow’ are very narrow like Italian cypress that grow only fifteen feet tall. ‘Wichita Blue’ and ‘Moonglow’ are stoutly conical. ‘Blue Arrow’ and ‘Wichita Blue’ are bluish green. ‘Skyrocket’ and ‘Moonglow’ are silvery gray. Established specimens do not require much water, but develop better foliar color with warmth and occasional watering.
Strictly formal boxwood hedges are traditional components of old formal rose gardens. In California, Japanese boxwood, Buxus microphylla, had always been more popular than English boxwood, which may be more common where winter is cooler. Although it grows too slowly for high hedges, it gets high enough to obscure gnarled lower growth of roses.
Mature plants are generally less than three feet tall and wide, although they can get a bit larger if they get a chance. The oval and glossy evergreen leaves are only about half an inch or an inch long, but relatively thick, so are very conducive to formal shearing. Foliar texture is nicely dense but not too congested. Gray or pale brown bark is seldom visible.
Old fashioned Japanese boxwood, which remains the most common in old gardens, has a somewhat light or yellowish green color. Modern cultivars are darker green. A common problem with old formal hedges is the addition of modern cultivars or even other species to fill gaps. The darker foliage will not conform to the lighter foliage, so ruins the formality.
Large shorn hedges or informal screens are the more popular functions of Pittosporum eugenioides. It works like a modern and more relaxed option to privet. What few garden enthusiasts know is that it can alternatively be allowed grow into a small tree, either as a standard (on a single trunk) or with multiple trunks. It grows rather efficiently to more than twenty feet tall and about half as broad while young, and as it matures, can eventually get about thirty feet tall and broad.
The glossy leaves have appealingly wavy margins and distinctively pale midribs. The slightly fragrant flowers are only pale yellow, and are not abundant among young trees. Big old trees often bloom enough in autumn to be pleasantly fragrant. Stems and foliage are lemony fragrant when pruned or shorn. However, the common name of ‘lemonwood’ (or tarata) is not so common locally for Pittosporum eugenioides.
Foliage is often employed to obscure views. Evergreen shrubbery or trees can provide privacy in the garden or for windows. It can just as easily hide unappealing buildings in the distance, or driveways where cars get parked. Unfortunately, too much foliage often obscures desirable views or interferes with lighting.
There are all sorts of reasons to control greenery that might otherwise get overgrown. Overgrown shrubbery and trees not only hides the architectural appeal of a home, but can also be a security risk by concealing windows and doors that burglars might break into, and by obscuring security lighting and street lights. Too much shade prevents lower plants from getting the sunlight they need.
The best way to limit overgrowth is by selecting plants that stay proportionate to their intended functions. For example, shrubbery below windows should naturally stay lower than the lower windowsills. Shade trees for areas where views should stay open should have high branch structure and relatively bare trunks. Well, most of know that this does not always happen.
The options are limited for greenery that wants to get larger than it should. Obviously, it can be pruned regularly; but this may be more work than it is worth, and can cause disfigurement Some plants can be pruned less frequently if pruned more severely, but will be bare and potentially unsightly for quite a bit of time. Overgrown plants can alternatively be removed and replaced with plants that are more proportionate to intended functions.
An option that is not often considered is an ‘updo’. Trees and large shrubbery that are obtrusive to views or lighting can be pruned up and over what they are being obtrusive to. For example, lower growth of large pittosporums that is covering low windows can be pruned away to expose bare inner trunks supporting higher growth. The lower trunks can be appealingly sculptural without being too concealing. This works nicely for large shrubbery like viburnum, bottlebrush, oleander, photinia and pineapple guava.
Street trees that interfere with street lights (or marquis on storefronts) may need to be updo pruned a few times for adequate clearance, but these procedures are much less work, are less disfiguring to the affected trees, and produce more appealing results than keeping trees down.
Johnny jump up and jumping cholla have no more than amusing names in common with hopbush, Dodonea viscosa. Neither a dangerous cactus nor a docile annual, hopbush is an elegantly upright and evergreen shrub. It is very popular for both informal and formally shorn hedging. With pruning, it can become a small tree with handsomely furrowed bark.
Hopbush has potential to get about as tall as a two story house, particularly with pruning for tree form. Conversely, with only occasional pruning for hedge form, it is just as happy to stay just six feet tall. Trees with single and straight trunks fit nicely into narrow spaces. Trees with a few irregular trunks that lean outwardly are more sculptural for larger areas.
The narrow evergreen leaves are about two or three inches long, with light bronzy color. ‘Purpurea’ has purplish bronze color, but does not grow as vigorously. Most hopbush are female, and generate interestingly papery seed. Bloom and seed production are variable though, and some specimens become male. Roots should be complaisant with concrete.
Of the several junipers that were too common decades ago, the golden pfitzer juniper, Juniperus X pfitzeriana ‘Area’, was the one outfitted with cheery, bright yellow new foliage each spring. Similar but more compact varieties that are more popular now were rare back then, or simply not yet invented. Contrary to the stigma, golden pfitzer juniper is a very tough shrub, which is why so many from decades ago remain in older gardens, and new plants can sometimes be found in nurseries. Once established, they need very little water, or none at all. A bit of partial shade is tolerable, but inhibits color. Angular branches radiate outward, with the finely textured foliage drooping only slightly at the tips. Mature plants get wider than six feet, and taller than four feet. Crowded plants can stand taller than six feet. Golden pfitzer juniper can technically be shorn as hedges, but are so much more appealing if selectively pruned to maintain their natural form. They are at their best where they have space to spread out naturally without pruning.
Almost all photinia in local landscapes is Fraser’s photinia, Photinia X fraseri, which is a thornless and fruitless hybrid of two species that are now rare. Some of the old fashioned photinia are thorny. Some produce copious berries that can get messy, or feed birds who can get messy. More modern cultivars of Fraser’s photinia are becoming more available.
Fraser’s photinia is popular as a shorn evergreen hedge. New foliage that develops after shearing is richly reddish bronze, and fades to dark green. Bronze color is best in spring, after late winter shearing. Summer shearing stimulates a repeat performance, although it may not last as long before the foliage fades to green. Shearing enhances foliar density.
Unshorn photinia can develop into small trees as tall as fifteen feet, with new growth that is a bit less richly colored than that of shorn photinia. It also blooms, often profusely, with big and rounded trusses of tiny creamy white flowers. Bloom is not impressively colorful. Floral fragrance is objectionable to some. All photinia types are susceptible to fire blight.
Where it had been left to develop naturally in old freeway landscapes, shiny xylosma, Xylosma congestum, grew as small trees. The largest are significantly taller than twenty feet. They can be pruned up to expose their nicely flaking bark on sculptural trunks and stems. The evergreen foliage is shiny and rather yellowish green, somewhat like that of camphor tree. The slightly serrate leaves are about two inches long or a bit longer. The tiny and potentially fragrant flowers are rarely seen, and not worth looking for. In refined landscapes, shiny xylosma is popular as a shorn hedge. Xylosma congestum ‘Compacta’ has denser growth, and can be kept only a few feet high if necessary. Vigorous shoots can have nasty thorns hidden in their deceptively gentle foliage. Once established, shiny xylosma does not need much water. It prefers full sun exposure, but will tolerate a bit of shade.