How to Propagate a Kalanchoe: Stem Tips and Leaf Cuttings From the Prunings

The prunings are the propagation material

Cutting back a kalanchoe after flowering and propagating it are the same job done in one sitting. The stretched, bare stems you remove carry perfectly good growing tips, and those tips root faster and more reliably than almost any other houseplant cutting. A plant that has gone leggy in a lit room is not a failure; it is a supply of five or six new plants.

The reason to take cuttings rather than just keeping the old plant is that a young kalanchoe is a much better shape than an old one. Stems get woody at the base and stop producing side shoots, so most growers restart the plant from cuttings every two or three years and discard the parent.

Timing and conditions

Take cuttings in late spring or early summer, when the plant is growing and the room is warm. Rooting wants 68 to 77F (20 to 25C) and bright shade. Cuttings taken in autumn root slowly if at all, and then sit in damp compost through the cold months, which is how they rot.

The one rule that matters more than any other with this genus is that the cut end must be dry before it goes into compost. A kalanchoe stem is full of sap, and a fresh wet cut pushed straight into damp compost rots at the base far more often than it roots. Two days on a windowsill is all it takes.

Rooting hormone is not needed and makes very little difference here. Drying the cut and keeping the compost only barely moist are the two things that decide whether a batch succeeds.

Stem tip cuttings, step by step

This is the main method and it is close to foolproof. Each leggy stem gives you one tip cutting, and a single overgrown plant usually yields four to six of them.

1. Cut a tip three to four inches long Take the top three to four inches (8 to 10 cm) of a stem with a clean sharp blade, cutting just below a pair of leaves. Choose firm growth, not a soft floppy tip and not a woody brown section.
2. Strip the lower leaves Pull off the leaves from the bottom inch and a half (4 cm) so the base of the cutting is bare stem. Any leaf buried in compost rots and takes the cutting with it.
3. Dry the cut end for two days Lay the cuttings on newspaper in bright shade for two days, until the cut face is dry and slightly corky. Do not put them in water; this plant roots in compost, and water-rooted stems rot on transplanting.
4. Push into gritty potting mix about an inch deep Insert each cutting an inch (2 to 3 cm) into a mix of cactus compost and perlite, or straight perlite, in a small pot. Firm gently so it stands up on its own. Three cuttings fit comfortably in a four inch (10 cm) pot.
5. Keep barely moist, in bright shade, at 68 to 77F Water once lightly at planting and then only when the surface has dried. Never stand the pot in water and do not cover it with a bag; the extra humidity that helps most cuttings rots this one.
6. Test with a gentle tug at three weeks Roots form in two to three weeks. Pull very gently on a cutting: resistance means it has rooted. Once it resists, start watering it as a normal plant and move it into full light.

Leaf cuttings

The leaves you strip off the bottom of your stem cuttings will themselves make plants, so a pruning session can produce far more than you need. Leaf cuttings are slower than stem tips and the resulting plants take a season longer to reach flowering size, but they cost nothing and use material you were about to throw away.

Take whole, undamaged leaves and pull them off cleanly at the stem so the base of the leaf stalk comes away intact. A leaf torn across the middle will not root.

1. Dry the leaves for two days Lay the leaves on paper in bright shade until the broken end has sealed. This matters even more for leaves than for stems, because a leaf has no reserve to fall back on if it starts to rot.
2. Lay them on the compost surface, base touching Rest each leaf on gritty potting mix or perlite with the base just in contact with the surface, or push the very base a quarter of an inch (5 mm) in. Do not bury the leaf.
3. Mist the surface, do not soak the pot Keep the surface barely damp by misting it every few days rather than watering. Standing water at the base of a leaf is the one thing that will stop the whole batch.
4. Wait for a plantlet at the base Roots appear in three to four weeks and a tiny rosette of leaves follows at the base after another month or two. Leave the parent leaf attached until it shrivels of its own accord; it is feeding the plantlet.
5. Pot up when the plantlet has four leaves Once the young plant has four or five leaves of its own, lift it with its roots and pot it into a two or three inch (6 to 8 cm) pot of gritty potting mix.

What to expect, and what to write down

A stem cutting taken in early summer will be a well-shaped small plant by autumn, which is exactly the right size to give the dark treatment for its first flowering. That is the natural rhythm of the plant: cut back and propagate in spring, grow on through summer, dark treatment in autumn, flowers in winter.

Record the date each batch went in, the method, and the date you first saw roots. Rooting speed varies a lot between rooms, and once you have your own figure you will stop pulling cuttings up early to check on them, which is the most common way of losing a batch that was rooting perfectly well.

Do not feed a cutting until it is clearly growing. Fertilizer on an unrooted cutting does nothing useful and the extra salts in the compost make rot more likely.