We all know about the bad reputation of eucalypti, especially the notorious blue gum. They are too big, too aggressive, too messy, too structurally deficient, and in groups, they are too combustible. However, there are several eucalypti that are not only appropriate for local home gardens, but because of their resiliency, drought tolerance and adaptability to the local environment, should be more popular than they are.
Red flowering gum, Eucalyptus ficifolia (which is now known as Corymbia ficifolia), rarely gets more than thirty feet tall and broad, with a stout branch structure. It is a good street tree because the roots are usually deep and complaisant. Constantly falling leaves and seed capsules are somewhat messy, but the mess is proportionate to the compact canopy, and is probably worth the spectacular summer and autumn bloom.
Fuzzy trusses of staminate flowers are usually some shade of red, but might be pink, salmon, reddish orange or pale white. Trees must be a few years old to bloom, so color might be a surprise when young trees bloom for the first time. Profusion of bloom can be variable from year to year, or from one portion of the canopy to another. Tree size and form are also variable. Some are vigorous while others are more compact.
Known more as a medicinal herb, and by its Latin name, coneflower or Echinacea, is a delightful prairie wildflower that works just as well in refined home gardens. It blooms in summer and again in autumn, although autumn bloom can be inhibited if plants are not groomed of deteriorating stems from the previous bloom. Like related gaillardia and rudbeckia, coneflower is a nice cut flower.
What an unflattering name for such striking tropical foliage! The pointed and strap-shaped evergreen leaves of mother-in-law’s tongue, Sansevieria trifasciata, stand vertically, about two or three feet tall. They are rather rigid, and seem to be plastic with a glossy finish. Almost all modern varieties are variegated with silvery gray, white, cream or yellow stripes or banding. Dwarf varieties stay shorter, with flared foliage.
One of the big four for mild climates, sweetgum, Liquidambar styraciflua, develops an excellent display of mixed yellow, orange and red, regardless of how quietly autumn tries to sneak in. Of the other three, Chinese pistache is more orange with less yellow, flowering pear is more ruddy, and gingko is only bright yellow. They all get very flashy color, but sweetgum just might be the flashiest.
From a simple picture, Spanish bayonet, Yucca aloifolia, is indistinguishable from the common giant yucca. The narrow leaves are about two feet long, and flare upward and outward from terminal buds. Plump conical trusses of waxy white flowers with purplish highlights stand vertically just above the foliage. The main difference is that the leaves are more rigid than they appear to be, with nastily sharp terminal spines.
Like redwoods, the cork oak, Quercus suber, is a ‘pyrophyte’, which means that it survives forest fires that burn off competing vegetation. The trunks and main limbs are insulated with a very thick bark. Only the foliage and smaller stems burn off. After a fire, the upper limbs of cork oak regenerate new foliage while other less fortunate plants start over from their roots or seed at ground level.
Bluegum is famously problematic. It is too big, too invasive, too messy, too structurally deficient, and as demonstrated in the Oakland fire, too combustible. Dwarf bluegum, Eucalyptus globulus ‘Compacta’, is a completely different animal that does not even look related. It gets only about fifty feet tall, with a dense and somewhat symmetrically rounded canopy. The mess and falling limbs do not affect such a large area.
In the west, the incense cedar, Calocedrus decurrens, was made into cedar chests or paneling for cedar closets as a substitute for the more traditional Eastern redcedar (which is incidentally a big juniper). The wood is supposedly aromatic enough to repel moths from woolens and furs. The evergreen foliage is very aromatic as well, so is sometimes used for garlands at Christmas time.
It is really an evergreen shrub with limber stems; but lavender starflower, Grewia caffra, can work almost like a rambling vine. It does not actually climb or grip anything. Like the canes of a climbing rose, it can be tied onto a trellis or fence as an espalier. As a free standing shrub, the arching stems should be pruned selectively. Shearing deprives them of their natural form, and inhibits bloom.
Yuccas are almost as useful as aloes are for gardening in chaparral or desert climates. I say ‘almost’ because most are not quite as friendly. The leaves are outfitted with nastily sharp tips. It is how they protect themselves from grazing animals in the wild, but it is not such an advantage in home gardens. Some actually have the potential to be dangerous where someone could bump into them. The leaves of Joshua tree can puncture leather. Some types of yucca get so big that they make it difficult to avoid their nasty leaves, even if planted in the background.
Tony Tomeo 