Not all palms are trees. Some lack trunks, so develop more as shrubbery. Some develop many slender stems, like bamboo. The thin canes of most rattan palms sprawl onto other vegetation for support, as vines. Mediterranean fan palm, Chamaerops humilis, develops multiple stout trunks, but grows so slowly that it can function as big sculptural shrubbery.
Old trunks can eventually get as high as twenty feet, and generally lean randomly. If they get too tall, smaller and more vigorous trunks can replace them. (An arborist can remove the bulky and thorny old trunks.) New trunks develop from basal pups, which can can get too densely foliated without occasional thinning. Removal of such pups might be difficult.
Mature trunks might be as wide as ten inches, with dense coats of basal petiole fiber and thorny petiole stubs. Thorough grooming can eliminate the stubs. However, petioles that suspend the evergreen palmate leaves are outfitted with the same wickedly sharp teeth. Leaves are about two feet wide. Atlas Mountain palm, Chamaerops humilis var.(iety) argentea has strikingly silvery foliage, and grows even slower.
Simple old fashioned New Zealand flax, Phormium tenax, has been popular on the West Coast for as long as anyone can remember. Big specimens are prominent in old pictures of Victorian era gardens. The upright and olive drab foliage gets as high as ten feet, and as broad as fifteen feet. Bronzed and variegated cultivars stay somewhat more compact.
Modern cultivars of New Zealand flax might be Phormium colensoi, or hybrids of the two species. They are generally even more compact, with more colorful foliage. Foliage may be olive green, greenish yellow, brownish bronze, rich reddish bronze or striped with like colors. Some bronze sorts are striped with tan or pink. ‘Yellow Wave’ has floppier foliage.
New Zealand flax is a tough evergreen perennial. Its long and narrow leaves can be too fibrous to cut without scissors. These leaves grow as tall as they do from clumping basal rhizomes. Interestingly rigid floral stalks stand slightly higher than the foliage, with yellow or red bloom. After bloom, these floral stalks can be a delightful and bold dried cut flower, and work well with pampas grass bloom.
Although it shares the same common name, Hypericum beanii is not the same sprawling Saint John’s wort that is now so aggressively naturalized within some local ecosystems. It is shrubbier and much more docile. Mature specimens get no more than three feet high and wide. It should be evergreen here, but can get sparse through cooler winter weather.
Bloom begins in the middle of summer and continues at least to early autumn. Cheerfully bright yellow flowers are two inches wide, with five rounded petals around fuzzy centers. The light green and oblong leaves are about two inches long. Stems are rather wiry, and can eventually get shabby. Coppicing as winter ends stimulates fresher vigorous growth.
Saint John’s wort prefers sunny and warm exposure. It is otherwise not very demanding. Regular watering enhances bloom. Yet, established plants can survive without watering. Where coppicing (cutting back to the ground) in late winter is not a problem, Saint John’s wort performs well as a low hedge, or unshorn border. Frequent shearing inhibits bloom. Rust is a potentially bothersome fungal disease.
Like so many of the plants that became too trendy at one time or another, giant yucca, Yucca elephantipes, had gotten a bad reputation. Some people still consider it to be cheap and common. The real problem though, is that some of the countless giant yuccas planted over the years went into situations that can not accommodate their massively distended trunks. Only a few of the largest specimens are taller than a two story house, and not many get broader than tall. However, their several sculptural trunks are remarkably bulky and flared at the ground.
The somewhat rigid and narrowly pointed leaves can get as long as three feet, and as wide as three inches. Foliage is typically slightly yellowish green, or richer green and a bit floppier in partial shade. Spikes of white flowers that bloom in spring are tall enough to stand just above the foliage, but are usually too high up to be too flashy. Individual flowers are actually only about an inch and a half wide. The bold form and texture of giant yucca work will with other bold plants like giant philodendron, various agaves and various cacti. Shoots and stems of any size that need to be pruned away can be stripped of lower leaves and ‘planted’ wherever new plants are wanted. They only need to be watered regularly until they develop roots like really big cuttings.
Prior to the appearance of oleander scorch disease in the early 1990s, oleander, Nerium oleander, was almost too popular, and for good reason. It is remarkably resilient to harsh conditions. It had been one of the more common plants within freeway landscapes since freeways were invented. Now, new plants are rarely available. Only older plants remain.
White, pink or red bloom is most abundant through warm summer weather, with sporadic bloom continuing through most of the year. Some dwarf cultivars bloom with peachy pink double flowers. Plants with enough room to grow wild without much pruning bloom best. Frequent shearing deprives the healthiest oleander of its blooming stems prior to bloom.
The biggest oleander get as tall as fifteen feet, so can be pruned up as small trees, either on single trunks or multiple trunks. However, because their limber trunks can not support much weight, occasional pruning is necessary while trunks develop. Such pruning limits bloom, so should happen mostly at the end of winter. Straight single trunks need staking. Oleander wants warm and sunny exposure, but is quite undemanding.
As long as freeways have been getting landscaped, oleanders have been contributing their profuse white, pink and red bloom. Heat, exposure and lack of moisture do not seem to bother them. They have become less common recently only because of new diseases that had never before been problematic. The diseases do not necessarily kill all oleanders everywhere, but are serious problems where the nurseries that grow most oleander are located.
The largest oleanders can get more than fifteen feet tall, and can be pruned up as small trees with multiple trunks. Oleander trees with single trunks almost never stand up straight, and do not want to give up their stakes. Because flower clusters develop at the ends of new growth, frequent exterior pruning or shearing inhibits bloom. Dwarf cultivars that are naturally proportionate to their space will bloom better than larger types that need to be pruned for confinement.
Oleander flowers are about an inch or two wide, with five petals, although some have ruffly ‘double’ flowers. Unfortunately, double flowers tend to hang on as they deteriorate after bloom. Some oleanders are slightly fragrant. The name ‘oleander’ is derived from the similarity of their leaves to those of olive trees (‘Olea‘), although oleander leaves can get three times as long.
The Nile River floods annually, inundating everything in its floodplain. Lily of the Nile, Agapanthus africanus, survives by hanging on firmly with a thick network of rubbery roots. It grows and blooms in warm weather as floodwater recedes, and then survives through a long, warm and dry season until the river floods again. It tolerates both drought and flooding, although it prefers more stability.
The blue or white blooms resemble fireworks, and happen to bloom in time for the Fourth of July. The small tubular flowers are neatly arranged in big and round trusses on top of slender and bare stems that stand about two to four feet tall. ‘Storm Cloud’ has darker blue or purplish flowers. Other purple varieties have larger and more pendant flowers (that hang downward from their trusses.)
The dense evergreen foliage is quite luxuriant, and is just as appealing as the bloom is. The rubbery leaves are up to two feet long, and arch outward from basal rosettes. Deteriorating lower leaves are typically obscured by fresh new foliage above. The thick rhizomes can be divided for propagation. Plants known as Agapanthus orientalis may have bigger blooms and wider leaves.
The delightfully clear sky blue flowers of blue plumbago, Plumbago auriculata, seem like they belong with colorful annuals or in a tailored border of colorfully blooming perennials. However, the rampant canes of mature plants are really best in the background where they have room to grow wild. The canes do not climb like vines, but can flop over other shrubbery as high as fifteen feet.
Rounded trusses of small blue flowers begin to bloom sporadically by the end of spring, and continue to bloom in phases until late summer. Supposedly, each subsequent phase should be a bit more profuse than the previous; but not all plants are aware of this. They might bloom best in mid summer, and less profusely later. ‘Alba’ blooms white. Pale foliage indicates a need for fertilizer.
Blue plumbago is not as easy to work with as it seems to be. Once established, it can grow like a weed, and really seems to take care of itself, and it is probably better to allow it to do so. It does not like to be shorn into hedges or geometric shapes as it so often is. Shearing ruins the natural form, eliminates most of the outer canes that provide bloom, and exposes sparse interior growth.
Oregon has good taste. Douglas fir, one of the most useful of timber trees in America, was selected as the state tree. Oregon grape, Mahonia aquifolium, was designated as the state flower. Although the tight clusters of tiny bright yellow flowers that bloom about now may not be as flashy as other state flowers, they contrast handsomely against the glossy and deep dark green foliage.
The pinnately compound evergreen leaves are larger than they seem to be. The smaller individual leaflets that resemble holly get noticed first. They are are not quite as wavy, spiny or thick as leaves of English holly are, so can work well where spiny foliage would be objectionable. Dark grayish blue berries are not abundant, but happen to make good jelly for those who hunt for them.
Mature plants get about five feet tall and broad, and can spread wider like Heavenly bamboo does. Foliage might be a richer shade of deep green, with a slightly more relaxed texture, in partial shade. A few garden varieties are available, including some that are more compact, and some with more rounded leaflets. Old canes should be pruned out as they get replaced by newer canes.
Pictures are probably prettier than the real thing. Australian fuchsia, Correa pulchella, really does bloom with pendulous soft pink flowers through winter when not much else is blooming. However, the flowers are quite small, and the color is rather hazy. The real appeal of Australian fuchsia is that it is so undemanding, and once established, only needs watering a few times through summer.
Mature plants get a bit higher than two feet, and maybe twice as wide, with a low mounding form. The small evergreen leaves have a nice density without any pruning. Obtrusive plants do not mind getting pruned back or even shorn for confinement, but are deprived or their naturally appealing form and texture if pruned too frequently. Good exposure for both sunlight and warmth is important.