Drought is nothing new here. There might yet be plenty of rain this year and for a few years afterward; but eventually, there will be another series of dry winters, prompting rationing all over again. Landscapers and big box garden centers continue with business as usual. It is up to us to manage our gardens responsibly. Even though they are not native, aloes, yuccas, junipers and eucalypti are four groups of formerly popular, drought tolerant plants that are worthy of more attention again.
Eucalypti had gotten a bad reputation even before they became popular the last time around in the 1970s. Tasmanian blue gum, Eucalyptus globulus, was planted extensively for wood pulp and timber throughout coastal California from the late Victorian period through the 1920s. Unfortunately, it is a huge and extremely messy tree and became invasive in areas where it was not wanted. Yet, it is still the most familiar of the eucalypti.
Garden varieties of eucalypti are much more docile. Even though they drop their evergreen foliage and hard seed capsules throughout the year, they do so on a smaller scale. The tall and elegant lemon gum constantly sheds strips of bark like the Tasmanian blue gum does, but does not get big enough to be too overwhelming.
Because they are so undemanding, and some are somewhat messy, eucalypti are best in unrefined parts of the landscape and away from lawn. Their mess is not so much of a problem over ivy or iceplant. Eucalypti are happiest where other trees might not be. Generous watering actually inhibits root dispersion, and can cause vigorous but structurally deficient stem growth.
Eucalypti innately prefer to be planted while very young, even from four-inch or one-gallon (#1) pots. Larger (and more expensive) trees, such as boxed trees, take so long to get established that they get passed up by faster growing smaller (and less expensive) trees. Because they are sensitive to confinement, eucalypti are unfortunately rare in nurseries.
Highlight on Silver Dollar Eucalyptus
There are a few different eucalypti known as silver dollar gum. The largest and most familiar is Eucalyptus polyanthemos. Mature trees that were popular and widely planted through the 1960s are now about forty or fifty feet tall. Some stay smaller. A few that compete with taller trees are more than sixty feet tall. Trunks and limbs are somewhat sculptural, with fibrous bark.
Grayish foliage on limber stems forms a billowy and rounded canopy that blows softly in the breeze. Juvenile leaves are nearly circular, and more silvery gray than adult foliage is, like silver dollars. Ovate adult leaves are about three inches long and half as wide. Tiny flowers with prominent white stamens bloom amongst the adult foliage in spring and summer.
Smaller trees are often pruned aggressively or pollarded so that they continually produce the more desirable juvenile foliage without bloom. The problem with this technique is that it must be repeated every few years or even annually. Otherwise, vigorous secondary growth can get too heavy and break away.