How to Propagate Aeonium: Beheading a Leggy Stem and Rerooting the Top

Why cuttings, and why this is not a rescue operation

An aeonium is built as a rosette on a stem, and the stem lengthens every year while the lowest leaves are shed. Over three or four seasons that produces a tall, bare, often leaning trunk with a head at the top. This is normal growth rather than a fault, though poor light accelerates it badly. The remedy is the same either way: cut the head off, reroot it, and keep the stump, which will branch.

Cuttings root exceptionally easily. A severed head with a couple of inches of stem, stood in dry gritty mix in the cool half of the year, is usually anchored within three to four weeks and growing within six. Leaf cuttings, by contrast, do not work on this genus. A detached leaf may sit green for months but will not produce a plantlet, so do not waste a season on it.

Timing

Take cuttings at the beginning of the growing season, meaning autumn after the heat breaks, or early spring. Both give the cutting months of active cool-season growing weather to build roots before it meets any real stress. Cuttings taken in the middle of the summer rest sit for weeks doing nothing, shrivel from the bottom up and often fail, so if a stem breaks in high summer, dry the cut end thoroughly and stand the head in an empty pot in bright shade until the weather cools before planting it.

Beheading and rerooting, step by step

The whole job takes ten minutes and the only part that people get wrong is the waiting. A cut surface pushed straight into damp mix rots instead of rooting, and the plant gives no second chance once that starts.

1. Cut the head off with two to three inches of stem Use a clean sharp blade and cut straight through the stem two to three inches (5 to 8 cm) below the rosette. A longer stub is easier to plant upright, a shorter one gives a more compact result. Cut into firm pale tissue and if the inside looks brown, cut higher until it is clean.
2. Strip the lowest leaves Pull off the bottom ring or two of leaves so the section that will be buried is bare. Pull them sideways and down so they come away cleanly at the stem rather than tearing a strip of bark with them.
3. Dry the cut for several days Stand the cutting somewhere dry, airy and bright but out of direct sun for 3 to 7 days until the cut end is dry and sealed to the touch. Do not stand it in water and do not use rooting hormone, neither of which helps and both of which invite rot.
4. Plant into dry gritty mix Push the bare stem an inch or two (3 to 5 cm) into a small pot of half-grit mix, deep enough that the cutting stands up on its own. If it will not stand, prop it against the pot rim or use a short cane rather than burying it deeper.
5. Wait a week, then water lightly Give no water for the first 5 to 7 days. Then water lightly, about a third of a normal soak, and repeat every 7 to 10 days. Keep the pot in bright shade for the first fortnight, then move it into full light.
6. Test at three to four weeks Give the cutting the gentlest sideways nudge. Resistance means roots have taken and you can switch to the normal watering routine. Free movement means wait another fortnight. Do not lift it to look.

What to do with the stump, and with side branches

Do not throw the decapitated stump away. Left in its pot in a bright spot and watered sparingly, it almost always pushes two or more new heads from dormant buds along the stem within a couple of months, which is how a single-headed plant becomes a branched one. This is worth doing deliberately even when the plant is not leggy, because a branched plant survives the death of any one rosette.

Side branches on an established plant are cuttings in their own right and are easier than a full beheading. Cut a branch off flush at the main stem, dry it for a few days and treat it exactly as above. Taking two or three branches from a crowded plant improves the shape of what is left and gives you spares, which matters more with this genus than most because of what flowering does.

Keep spare cuttings rooted at all times. A rosette that flowers will die afterwards, so a plant with several branches, or a pot of rooted cuttings on the side, means a flowering season never costs you the plant itself.

Seed, and what to write down

Seed is possible but rarely worth it for a plant you already have. Sown on the surface of a fine gritty mix at around 65F (18C) in autumn, seed germinates in two to three weeks, but seedlings take two to three years to reach any size and the genus hybridises so freely that they will not match the parent. Take cuttings if you want the same plant, sow seed only if you want unpredictable new ones.

For every cutting, write down the date you took it, the date you first watered it and the date it resisted the nudge test. After a few batches you will have your own rooting time for your conditions, usually somewhere between three and six weeks, and that number stops the second-guessing that makes people dig cuttings up to check. Note which parent plant each batch came from as well, since a bench of rooted heads becomes anonymous within a season.