Question: What’s the secret to growing an aloe from a leaf cutting? I’ve tried it twice, but each time the leaf just rots away without producing a baby.
Answer: It’s not surprising your attempts were unsuccessful, because it’s impossible to grow aloes from leaf cuttings. It’s yet another garden myth.
The leaf of the medicinal aloe, also called true aloe (Aloe vera)—I presume that’s the variety you’re talking about—simply doesn’t produce adventitious buds (dormant buds capable of producing an offset) on its leaves. As far as I know, no other aloe (and there are more than 500 species of them!) will grow from leaf cuttings either. They just don’t have what it takes to do so.
But I Saw It on the Internet!
What is curious is that there are many websites that claim quite the opposite. Even very serious ones you’d think would know better than to spread false information! Some even go so far as to explain how to make aloe leaf cuttings!
These sites often offer contradictory advice: “make a clean cut” versus “crush the wounded end”; “leave the leaf intact” vs “cut it into sections”; “let the wound heal before planting” vs “insert the cutting into potting soil immediately”; “stand it upright” vs “lay it on its side”, “apply a rooting hormone” vs “don’t apply rooting hormone,” etc. Some even show step-by-step photos of the recommended process … except that the last picture, the one that should show the result, a beautiful baby plant growing from the base of the leaf cutting, is always missing.
On the other hand, if you do an Internet search on how to take leaf cuttings of haworthias (Haworthia spp.) or gasterias (Gasteria spp.), two genera closely related to Aloe (all three belong to the subfamily Asphodeloidea of the Xanthorrhoeaceae family) that have the reputation of being easy to multiply by leaf cuttings, you will have no difficulty in finding photos showing plantlets of those two sprouting from the base of a leaf cutting.
If leaf cuttings from aloes, far more popularly grown than haworthias or gasterias, were possible, wouldn’t you think photographic evidence would be abundant?
Division: The Best Way to Multiply Aloes
There is no doubt that the easiest way to multiply medicinal aloes is by division. In general, they produce many pups, even from a very young age, making this method highly popular. You just have to separate a pup or two from the mother plant, preferably leaving each “baby” a few roots of its own. You can do this by delicately digging at the base of the plant to free them or by unpotting the entire plant, knocking the soil mix off, and then pulling apart the resulting horde of babies. After that, it’s simply a question of potting them up into their own little pots, then watering little at first; more when the “babies” start to grow. Note that pups with at least 4 leaves are easier to grow successfully than less mature divisions.
Stem and Rhizome Cuttings
At first glance, the medicinal aloe doesn’t look like it has much potential for stem cuttings. After all, the species is stemless (it produces a ground-hugging rosette, with no visible stem (although it may produce a more visible stem if it etiolates due to insufficient light) and you can’t take a stem cutting from a plant that has no stem. But there is a stem: it’s just that it’s hidden by dense, overlapping leaves. Normally, you’d only consider taking a stem cutting when the mother plant is dying, perhaps due to root rot (a not infrequent occurrence).
To do so, simply cut off the top of the plant above any sign of rot and pull off a few rows of lower leaves, leaving a section of bare stem 1 to 2 inches (2.5 to 5 cm) long at the base of the stem, then insert it into a pot of soil. Don’t even water for a week or so, so the wound can heal a bit, then begin watering gradually, increasing as roots begin to form. Within 3 months, the plant should have fully recovered.
(Note that there are many species of shrubby and creeping aloes that don’t produce stemless rosettes, but rather branching stems of well-spaced leaves. They’ll be much easier to multiply by stem cuttings.)
You can also take rhizome cuttings. As it ages, the plant develops a thick underground stem (rhizome) that you can cut into sections. When planted up, these sections will quickly produce young plants.
There is a way of succeeding with what may look a lot like a leaf cutting. That is, if you manage to harvest a small section of stem along with a leaf, such is if you cut a leaf free, making sure the base of the stem remains attached, rather than pulling one free. That will ensure a piece of stem from which the plant might regenerate if planted up. This might look like a leaf cutting, but is really a form of stem cutting, since the dormant bud that led to the new plant came the stem, not the leaf. Also, it’s hard to think of a situation where this method would be superior any other method. We’re pretty much scraping the bottom of the barrel here!
Of course, you can also multiply aloe by seed if you want. Sometimes, after flowering, aloes growing outdoors produce seed pods (this rarely happens on indoor aloes due to the absence of pollinators) and if so, you could harvest and sow the resulting seeds when the pods open. If not, the seeds of several species of aloe are easy enough to find on the Internet. Just sow them indoors just like any other plant. Germination is a little slow, but very easy to obtain.
Finally, you could probably also try micropropagation of aloes using meristem tissue … but that’s more likely something you’d want to do in a laboratory than in a home garden setting.
With that, we’ve reached the limit of ways of multiplying an aloe … and it simply doesn’t include leaf cuttings!