How to Propagate an Agave: Offsets Are the Only Sensible Way

Why offsets, and only offsets

An agave grows from a single central growing point. Remove or damage that point and the plant cannot make a new one, which is why the propagation methods that work on most succulents simply do not apply here. A leaf pulled off an agave has no growing point in it and never will. It sits, browns and rots, however carefully you treat it.

What the plant does instead is send out short underground stems that surface as small rosettes around the base, often a hand's width away, sometimes several feet out. These pups are complete plants with their own growing points, and every one of them can become a full-sized agave. Take those and you have a reliable, fast, free method that needs no equipment.

Choosing a pup worth taking

Not every pup is ready. A tiny one still drawing everything from the parent will sulk for a year or die outright, while one that has already put out its own roots establishes almost without checking. Wait until a pup is a third the diameter of a dinner plate or has at least five or six of its own leaves, and if you can scrape the soil away and see white roots of its own, better still.

Take pups in late spring or early summer, in warm weather with the whole growing season ahead. The parent and the pup both have open wounds afterwards, and warmth is what closes them quickly.

1. Let the soil dry first Stop watering for two weeks before you start. Dry soil crumbles away from the connecting stem so you can see exactly where to cut, and dry wounds seal instead of weeping.
2. Uncover the connection Scrape soil away from between the pup and the parent with a hand fork until you can see the short stem joining them. Do not tug on the pup to find it.
3. Cut cleanly, close to the parent One decisive cut through the connecting stem with a sharp clean knife or pruners, leaving an inch (2.5 cm) or so of stem attached to the pup. Ragged tears on either side are what let rot in.
4. Lift the pup with any roots it has Ease it out with a trowel and keep whatever roots come with it. Brush the soil off rather than washing them.
5. Dry both cut surfaces Leave the pup somewhere warm, shaded and airy for five to ten days until the cut is dry and hard to the touch. Leave the parent's wound uncovered and unwatered for the same period.

Wear gloves, long sleeves and eye protection throughout. Even a small pup has sharp leaf tips, and the sap that runs from the cut stem irritates skin, often hours later rather than at the time.

Potting the pup

Pot into a small container, barely wider than the rosette, in the same gritty mix you would use for an adult: about half potting mix, half coarse grit. A small pot is deliberate. It dries quickly, and quick drying is what a rootless or barely rooted pup needs while it decides to grow.

Set it so the base of the leaves sits at the surface, with the short stem buried but the crown clear. Push a couple of small stones against the base if it will not stand up rather than burying it deeper. Then leave it dry.

A gentle tug tells you when it has rooted. If the pup resists and the whole pot lifts, roots have taken hold and you can move it to full sun and normal watering.

The one-off harvest: flowering, bulbils and the end of the parent

An agave is monocarpic. After many years, sometimes ten, sometimes several decades, it throws a single enormous flower spike from the center of the rosette, flowers, and then dies. This surprises people badly, because the spike is spectacular and looks like a sign of health, and it is: it is the plant spending everything it has stored. Nothing you do will save the parent afterwards.

That event is also a propagation opportunity. Many agaves produce small plantlets, called bulbils, along the flower stalk after the flowers fade. Each one is a complete miniature plant. Let them grow on the stalk until they have a few leaves and small aerial roots, then twist them off and pot them exactly as you would a pup. A single stalk can give you dozens.

Meanwhile the pups around the base are the parent's real succession. Leave them attached while the flower spike develops and let them take over the space, or lift and pot them. Either way, a flowering agave does not mean the end of your agave, provided it had made offsets first.

Keeping track

Label every pup with the date you cut it and where the parent stood. Agaves grow slowly enough that a year later you will genuinely not remember which pup came from which plant, or whether the one that is sulking was cut in spring or in autumn.

Record the date each pup rooted, and note how big it was when you took it. After a couple of rounds a pattern appears: pups taken above a certain size root in about a month and the smaller ones take three, and that tells you exactly how long to wait next time. If a parent starts to send up a flower spike, record that too, alongside the year you first planted it. That number, the age at flowering, is worth more than any general figure because it applies to your conditions.