One of the most widely grown succulents in California from the coast to the foothills is Aloe arborescens (torch aloe).
There’s no need to buy it. It’s so common, it’s a “pass-along plant,” meaning friendly neighbors who grow it will likely give you cuttings.
But before you go knocking on doors, here’s what you need to know to grow Aloe arborescens and keep it thriving.
Easy-care aloe
Aloe arborescens is from southeastern Africa. Its found from Mozambique to Cape Town in South Africa---regions climactically similar to California from the Bay Area to San Diego.
This is one of the easiest landscape succulents. Aloe arborescens doesn’t get unmanageably large, although the species name means "treelike."
Beach garden with Aloe arborescens
It isn’t treelike at all. Rather, rosettes form a multi-headed colony over time, which can be as tall as 7 feet when in bloom. Such mounds are easy to whack back. Discard the cuttings, tuck them into garden gaps, or pass them along.
A beach-lover
These dramatic plants do fine exposed to salt spray.
Aloe arborescens in Laguna Beach, CA
I think of Aloe arborescens as "the Laguna Beach aloe," because it has naturalized along the cliff-top walkways of that city by the sea.
Those flowers!
Even as a child, I was fascinated by the flowers. Two-foot-tall coral-red spires of elongated, beadlike buds attract bees and hummingbirds.
Aloe arborescens flowers contrast with blue sky and yellow euryops daisies
Against a blue sky, torch aloe flowers are unforgettable.
Best of all, like the majority of aloes, arborescens blooms midwinter, when little else is going on in the garden.
Gel and teeth
The gel is harmless but can stain clothing. Like its famous relative, Aloe vera, the gel of Aloe arborescens can be used medicinally, although I don’t recommend it. It’s a purgative, meaning it’ll cause cramping and rapidly clear out your digestive tract (!)
Aloe arborescens gel in a split-open leaf
Toothed edges of aloes look intimidating but are no more likely to draw blood than prickles of hardened wax...which they look and feel like.
Fire-retardance
Torch aloe's gel-filled leaves and tendency to form dense mounds make it an effective firebreak.
Several years ago I conducted an informal experiment (see my video, Do Succulents Burn?). I placed cuttings of various commonly-grown succulents from my garden onto a blazing fire. Without exception, they charred but didn't catch fire nor did they transmit it. Basically, the plants cooked.
I tested the flammability of Aloe arborescens on a gas-flame fire pit.
I'm not claiming that Aloe arborescens or other succulents can prevent a home from burning. Only that their high moisture content makes them significantly more fire-retardant than thin-leaved, woody plants.
I'm not alone in considering them a must-have plant for wildfire-prone areas of California---ideally planted around a property's perimeter. Fire prevention agencies recommend aloes too.
How to start cuttings
Aloe arborescens starts readily from cuttings. Slice the stem about a foot below the top of a rosette. Dig a hole big enough to hold the stem upright, insert it, and firm the soil around it. In a few weeks, roots will grow and anchor the plant.
In the video, I demonstrate taking a cutting. This one came from the outer, lower part of the mound.
Succulent cuttings can't grow without roots, but they won’t die without them either. At least, not for a long time. Cuttings of aloes are typical; they live off the moisture in their leaves---which btw is the definition of a succulent.
Soil, water, fertilizer
In a mild climate, an established colony of Aloe arborescens can get by on rainfall. However, the plants will be more lush and healthier if hosed every few weeks in summer and fall.
Aloe arborescens doesn’t require rich soil, as long as it’s well draining. Nor does it need fertilizing or irrigation. But it doesn’t mind them either, in fact, it grows more vigorously when pampered.
An aloe indoors with inadequate light
Aloes---most plants for that matter---need sunshine in order to bloom and photosynthesize. They tend to sulk as houseplants, flattening their leaves to expose maximum surface area to available light.
Sun and heat
Along the coast, Aloe arborescens wants all-day sun; farther inland, some protection from scorching afternoon sun in summer and frosty nights below 25 degrees F in winter.
You won’t see Aloe arborescens in the desert, except perhaps in dappled shade, because summer sun and heat are too strong.
Varieties
Alhough most often green-leaved and orange-flowered, Aloe arborescens has sub-varieties that collectors consider cool.
Aloe arborescens 'Lutea'
For example, Aloe arborescens ‘Lutea’ has yellow flowers; and leaves of Aloe arborescens ‘Variegata’ (my favorite) are striped green-and-cream.
Isn't Aloe arborescens 'Variegata' gorgeous?
Pests and problems
The biggest concern with aloes, regardless of species or variety, is a microscopic mite that infests the tissues. It causes cancer-like growth that resembles tree burls.
Aloe arborescens 'Variegata' exhibiting aloe mite
Such growths have an intriguing weirdness, but please do us all a favor and remove them to keep the mite from spreading.
Aloe flowers distorted by aloe mite
Remove deformed flowers as well, because mites travel on air currents. And don’t pass along cuttings of infested plants. Once an aloe has the mite, it always has it.
The only other problem I’ve encountered during decades of growing Aloe arborescens in my Zone 9b garden northeast of San Diego, was that after a particularly rainy winter, numerous leaves had dark, pitted spots.
Black pitted areas on leaves indicate a fungal disease
I cut the plants back to healthy growth, discarded anything diseased, drenched stems and remaining leaves with copper fungicide, and in six months the plants grew back better than ever.
Questions?
If you love aloes---and Aloe arborescens in particular---and have observations to share or questions to ask, by all means do so below in the Comments or on my corresponding YouTube video.
I look forward to hearing from you!
Its flowers glow beautifully when backlit, and (gasp) are gorgeous mirrored in still water.
