torch aloe (Aloe arborescens)

Nearly everything that grows in South Africa will grow in the San Fernando Valley, too.
That’s because the climates of these coastal corners of two continents are virtually mirror images of one another. While Los Angeles’ latitude is 34 degrees north of the equator, Cape Town’s latitude is 33 degrees south of the equator. The difference is expressed in opposite calendar seasons. Just as we clean out our rain gutters and prepare for winter, South Africans are taking their swimsuits out of storage and getting ready for summer.
No plant better represents South Africa than Aloe arborescens. Its succulent leaves impart drought tolerance, essential in a land where rain is absent most of the year. At the same time, its flowers provide a colorful counterpoint to overcast skies during the coldest months.
Its species name, arborescens, which means treelike, is a misnomer since it is anything but a tree. Call it a tall ground cover, a sprawling shrub or a living fence, but it definitely does not have a trunk.
Instead, the species sobriquet of arborescens may be explained by its tendency to branch out in every direction. When it comes to propagation, this is a desirable trait since you can cut off any branching shoot, stick it in the ground, and it will soon put down roots and develop into a new plant of its own.
In South Africa, Aloe arborescens is known as krantz aloe, the reason being that krantz is the Afrikaans word for rocky cliff, and Aloe arborescens is famous for growing along mountain ridges at an elevation of several thousand feet. At the same time, its distribution is vast and it may be found thriving at sea level.
Torch aloe is another one of its names and refers to its flaming inflorescences that are visible during the winter season. Over time, a single torch aloe may grow into a massive 10-by-10 foot candelabra.
In South Africa, torch aloe is used as an ornamental, inexpensive fence for the confinement of livestock. It is also more medicinal than any other aloe species, with the exception of aloe vera. The sap of Aloe arborescens is beneficial in soothing burns and research has shown that a lectin isolated from its sap may be beneficial in treatment of some cancers and immunological disorders.
In any event, if you want to be surrounded by vivid orange-red in winter, Aloe arborescens is the species for you. Cultivars with yellow flowers are also available.
Nearly all red-hot poker (Kniphofia spp.) plants bloom in spring, summer or fall, but a few cultivars prefer to flower in winter. One of those is on display at the Conejo Valley Botanic Garden. Although they are in the same family as the aloes, red-hot pokers, also known as torch lilies, need more water to thrive. While they can survive in a drought-tolerant garden, expectantly holding out for an injection of winter rain, they will do better when regularly watered in hot weather.
Signature red-hot poker flowers glow in red, orange and gold, but there are species and cultivars that bear magenta and white, burgundy and green, lime green, and pure butter-yellow torches, too.
Winter is the swan song season for foxtail agave. Its botanical name of Agave attenuata is easily recalled because of its attenuated – elongated – arching flower spike. While most agaves are spiny, this one is softer than felt. However, in the manner of all agaves, the plant dies when its flower fades. As is the case with most agaves, foxtail agave produces numerous offsets, or pups, in the course of its life so that the death of a single flowering plant is more than compensated for by a surrounding host of clonal offspring.
Apple galls on oak trees
Have you ever noticed a brown golf ball hanging from an oak tree? This spherical growth, known as an apple gall, is created by a small wasp. The wasp lays eggs in an oak stem and, in response, cells in the stem reproduce abnormally until they assume the shape of a green globe that later turns brown.
This growth is called a gall since bitter- tasting tannins are a major chemical constituent. When the wasp larvae hatch they feed on the gall until they are big enough to make exit holes in the gall and continue their metamorphosis into adult wasps. Galls do no harm to oak trees, and insecticides would be useless since they cannot penetrate the gall casing and would not affect the wasps inside.
Distinctive winter flowers
At Armstrong Garden Center in Sherman Oaks, I recently observed a few winter flowering plants of note: Camellia sasanqua ‘Yuletide,’ one of the most floriferous sasanquas, with cherry-red petals surrounding fat circles of golden stigmas; a new picotee blue and white Cineraria with daisylike petals; Arctotis daisy cultivars in yellow, orange and mauve; and shade-loving perennial leopard plant (Farfugium japonicum ‘Aureo-maculatum’), with large yellow spots on orbicular leaves and deep yellow flowers borne on uncanny 2-foot stems.
Tip of the week
While visiting Culver City the other day, I spotted a 5-foot-tall poinsettia hedge the likes of which I had never seen before. The plants were outstanding both for their compact growth and excessive display of red bracts, modified leaves that are often mistaken for poinsettia flowers. Bracts are the papery appendages that give color to bougainvillea, too.
Usually, when you see a poinsettia growing outdoors, you notice a cluster or two of bracts on a rangy, pale-green plant and acknowledge, “Oh, yeah, that must be a poinsettia.” Here, however, the tight, dark-green vegetative growth and superabundance of bracts made it seem that this variety had been bred for outdoor use.
It must be noted that poinsettia (Euphorbia pulcherrima) is frost tender and would certainly have an advantage growing in more temperate Culver City as compared to the frostier San Fernando Valley.
If you wish to plant your poinsettia outdoors, wait until March, when the danger of frost is over. Make sure it gets a half day or more of good light but that it is not exposed directly to more than an hour or two of afternoon sun since it could burn in too much heat. It would also be beneficial to situate it next to a wall since heat radiating from the wall on a cold night would help protect it in the event of a freeze.