These exotics are colorful, easy and drought-tolerant
If you have little interest in garden design and just want to decorate your yard with plants that have exotic looks, you can do that by focusing entirely on two botanical genera: Euphorbia and Kalanchoe. Most of them are drought-tolerant, coming from arid habitats in Africa and Madagascar.
In the year 12 B.C., King Juba of Numidia (North Africa) was suffering from a prolonged illness. When he recovered, he named the plant that cured him after the Greek physician, Euphorbus, who prescribed it. Today, euphorbias are commonly referred to as spurges. Spurge is derived from the Latin “expurgare,” which refers to the purgative or laxative effect of euphorbia sap.
One of the most common weeds this time of year is petty spurge (Euphorbia peplus), which grows 6-10 inches tall with discrete tiers of attractive, 1-inch oval leaves. It spreads rapidly but is an annual with a superficial root system and is therefore not a nuisance. In fact, a large patch of petty spurge is a delight to the eyes. The sap of this ubiquitous weed has been used in the treatment of nonmelanomic skin cancers.
Euphorbia sap can be curative but it can be dangerous, too, depending on the species. The most widely planted ornamental euphorbia in Los Angeles gardens is Euphorbia tirucalli. It is known as pencil tree since its leafless stems vaguely resemble those familiar writing utensils, and it can grow up to 30 feet tall, even though it is typically kept shrubbier as a garden ornamental. The Sticks on Fire variety, first brought to Los Angeles from South Africa by legendary plant explorer Gary Hammer, has stems that appear in glowing pink, orange and yellow. You see it everywhere.
Be careful with pencil tree sap since getting it your eyes may cause blindness for several days, and it has proven to be carcinogenic. Burkitt’s lymphoma is the most common childhood cancer in central Africa, and research has indicated that pencil tree sap is a causal agent of the disease. In tropical Africa, pencil trees are commonly used for fencing. Pencil tree stems are easily snapped off and children play with the gooey, pathogenic latex sap that oozes out. While various preparations of pencil tree sap have also been used to treat a range of conditions in some countries, it’s obviously not recommended.
Most euphorbias are easy to grow because once established, they need little if any water. This includes the leafy types such as Mediterranean spurge (Euphorbia characias wulfenii), which should be flowering any day now.
This spurge species is a glorious conglomeration of robust drumstick inflorescences in chartreuse yellow. The erect flower wands are complemented by blue-green foliage.
The leaves of some euphorbias are colorful, such as Euphorbia x martinii “Ascot Rainbow,” whose foliage is pink, blue, green, and yellow. Silver spurge (Euphorbia rigida) is widely planted due to its toughness, enhanced by perfectly contrasting yellow bracts and silvery-blue foliage. Here is an ideal plant for a slope to which access is limited. Silver spurge self-sows and so for the price of a few plants, you will have a large crop of them sprouting up within a few years’ time.
The most famous euphorbia does not come from far away but is indigenous to Mexico and Central America. I am talking about the poinsettia (Euphorbia pulcherrima), named for Joel Poinsette, the United States ambassador to Mexico 150 years ago, who popularized the plant — eventually named for him — by sending cuttings of it back to his native South Carolina. Later, he made a living by growing and propagating the plants in greenhouses.
Like all euphorbia species with colorful terminal appendages, the red or pink color that you see in poinsettias is not from flowers but from modified leaves known as bracts. The tiny yellow flower buds encircled by the bracts do serve a useful purpose, however. Tightly closed buds are a sign that the plant is fresh. Once they have opened, the color of the bracts quickly fades.
You can plant the poinsettia you got last winter in your garden if you live by the coast. If you live inland, plant it against a wall, since the heat absorbed by the stone or stucco during the day will radiate out at night, protecting the cold-sensitive poinsettia in case of a frost. Poinsettias will accept regular irrigation but are also drought-tolerant. At this time of year, you can detach 6-8 inch cuttings from your poinsettia, dip the bottom third of the stems in root hormone (available in nurseries or through online vendors) and insert them into a mix that is half perlite and half peat moss. Roots will begin to form soon enough.
Poinsettias aside, crown of thorns (Euphorbia milii) is the most brilliant of the spurges. Its red bracts are visible 365 days a year. An excellent crown of thorns display may be found on the north side of Ventura Boulevard just west of the 405 Freeway, in the sidewalk planter of the hotel located there. Although reasonably cold-tolerant, crown of thorns should be covered with protective material when freezing temperatures are forecast.
The name kalanchoe — pronounce it either ka-lanKO-ee or ka-lan-CHO-ee — may sound eerily exotic and, if truth be told, some of the plants included in this genus are precisely that. Kalanchoe beharensis “Fang,” for example, has toothy growths extruding from its leaf surfaces; its tapered, felt-textured, triangular leaves grow up to 8 inches long, and the plant itself will eventually rise to an arboreal height of 10 feet. Flapjack or paddle plant (Kalanchoe thyrsiflora) has a series of rainbow-colored discs that will eventually rise up from the ground on 4-foot stems. Panda plant (Kalanchoe tomentosa) has furry, teddy bearlike appendages that pass for leaves. It grows into a bushy specimen up to 3 feet tall. Copper spoons (Kalanchoe orgyalis) has furry copper leaves and brilliant yellow flowers. Lavender scallops (Kalanchoe fedtschenkoi) has lavenderish, scalloped foliage with salmon bells for flowers.
The name “kalanchoe” has two possible derivations. According to most authorities on the subject of plant name origins, kalanchoe is composed of two Chinese words — “kalan chauchy” — which mean “that which falls, grows,” and refers to the fact that tiny plantlets, with baby roots attached, are produced on the leaf margins of certain species. When they fall from the leaves, these plantlets root where they drop and eventually grow into full-fledged adult specimens. Mother of thousands (Kalanchoe daigremontiana) is the classic species for illustration of this phenomenon. Alternatively, some botanists believe the name comes from two Hindi words — “kalanka,” meaning rust, and “chaya,” meaning glossy, a reference to the glossy red leaves of a particular species from India.
Kalanchoe is distinguished by the fact that nearly half of its 125 species are native to Madagascar, a large island nation off southeast Africa. Islands tend to have their own distinctive flora or endemic species due to their isolation. “Endemic” is a word used to describe any species, plant or animal, whose habitat is restricted to a single place on earth, and nearly all the Madagascar kalanchoe species are endemic to that island.
Florist’s kalanchoe (Kalanchoe blossfeldiana) has shiny foliage and silky, long-blooming flowers in red, orange, salmon or yellow. Doubleflowered types whose blooms resemble roses are widely available. A sample of this species that I planted in midDecember is still flowering. All kalanchoes may be propagated from stem cuttings or individual leaves. The latter are detached and inserted vertically with their bases in a fast-draining soil medium; alternatively, leaves may be laid down flat on one side, flush with the same medium.
Note: Thanks to Karen Husmann and Nancy Harris for pointing out that a photo of sugar bush (Rhus ovata) was mistakenly captioned as lemonade berry (Rhus integrifolia) in a recent column. How to tell them apart? Both correspondents noted that sugar bush leaves are bent upward “like a taco shell.”
Please send questions, comments, and photos to joshua@perfectplants.com. For more information about area plants and gardens, go to Joshua Siskin's website, thesmartergardener.com.