How to Propagate Nandina by Division, Cuttings and Suckers

Which method to use

The clumping habit that dictates how nandina is pruned also dictates how it is multiplied. The plant is constantly sending up new canes at the edge of the clump, each with its own developing roots, and separating those is far simpler than persuading a cutting to root. If you already have an established plant, division is almost always the right answer.

Cuttings are the method for producing a number of plants from one, or for taking material away from a garden you cannot dig in. They root reliably enough but take a season to make anything you would plant out, and two or three seasons to make a plant of any size.

Seed is a poor choice for a gardener and a real problem for everyone else. Seedlings are slow, uneven and take years to reach a useful size, and the berries that produce them are the same berries that spread the plant into wild ground and poison birds. There is no reason to raise nandina from seed when division works this well.

Dividing an established clump

Division is done in late winter or very early spring, while the plant is dormant and before new growth is moving. At that point the top growth is not making demands on the roots, the cane structure is easy to read, and the divisions have the whole spring to settle in. A clump of five years or more will divide into two or three good plants without difficulty.

1. Cut the canes back first Shorten the canes on the section you are about to move to about a foot (30 cm) before you dig. A reduced top makes the plant easier to handle and cuts the water demand on a root system that is about to lose half of itself.
2. Dig a full circle around the clump Push a spade in vertically a foot (30 cm) out from the outermost canes, all the way round, before levering anything up. Cutting cleanly on all sides first prevents tearing the roots on the far side as you lift.
3. Lift and wash off enough soil to see the crown Get the clump onto a sheet or a barrow and hose or shake enough soil away to see where the canes join the root mass. You are looking for natural groupings of canes with their own roots underneath.
4. Separate rather than chop where you can Work the sections apart by hand or with two forks back to back. Where the crown is genuinely woven together, cut through it with a sharp spade or a pruning saw, keeping each division to at least three or four canes with a good share of root.
5. Replant immediately at the same depth Get the divisions back in the ground the same day with the crown at soil level, never buried. Water them in thoroughly to settle the soil around the roots and remove air pockets.
6. Water weekly for the whole first season A division has lost a large share of its root system and cannot be treated as an established plant. Two to three gallons (9 to 14 liters) weekly through the first growing season, and through drought in the second.

Label each division with the date it was separated and where the parent clump stands. A division looks static for its first summer and it helps a great deal to know whether you are looking at something planted three months ago or two years ago before you decide it has failed.

Detaching suckers, the easiest option of all

If you only want one or two extra plants, you do not need to lift anything. An established clump throws up single canes at its outer edge, a few inches to a foot (10 to 30 cm) clear of the main body, and each of those has made its own roots along the connecting stem underground.

In late winter, push a spade down vertically between the outlying cane and the parent clump to sever the connection, then dig the cane out with as much root as you can keep. Pot it into a two gallon (7 to 8 liter) container of free-draining compost, or plant it straight out if the roots came away well.

Cut the cane back by about half at the same time. A detached sucker has a small root system and a full length of foliage to support, and reducing the top is the difference between a plant that sits and sulks and one that pushes new growth in spring.

This is also how you deal with canes appearing where you do not want them, at a lawn edge or across a path. Rather than cutting them off and having them return, dig them out with the root and either pot them up or dispose of them.

Semi-ripe cuttings

Take cuttings in late summer, from wood that grew during the current season and has firmed up but is not yet fully woody. The test is to bend a shoot: it should flex and spring back rather than either flopping limply or snapping. Work in the early morning when the material is fully charged with water.

Cut sections four to six inches (10 to 15 cm) long, trimming immediately below a leaf joint. Strip the leaves from the lower half, and reduce the remaining leaflets by about half to cut water loss while the cutting has no roots. Dip the base in rooting hormone, which noticeably improves the strike rate on this plant.

Insert the cuttings around the edge of a pot of gritty free-draining compost, half perlite or sharp sand by volume, so the cut end sits firmly in contact with the mix. Water once, then cover with a clear bag or put the pot in a propagator, keeping it out of direct sun in a bright warm place.

Expect roots in six to ten weeks. Test by tugging gently: resistance means roots. Once rooted, ventilate gradually over a fortnight before removing the cover entirely, then pot up individually and grow through the following season before planting out. Do not plant a first-year rooted cutting into open ground going into winter.

Why seed is the wrong route

It is technically possible to grow nandina from the berries. Cleaned of pulp and sown fresh in autumn in a gritty mix left outdoors over winter, seed germinates in spring, unevenly and over a long period. The seedlings then need two or three years to reach the size of a small container plant.

The reason to avoid it is not the difficulty. It is that the fruit is the part of the plant that causes trouble. Berries left on the plant into winter are eaten in bulk by flocking birds and contain cyanogenic compounds that have killed them; the same birds spread the seed into woodland where nandina has become invasive in parts of the southeastern United States. Keeping fruit on the plant in order to harvest seed works directly against the removal that is otherwise the right thing to do.

Division gives you a full-sized plant on the same day, from a clump that is going to need thinning anyway. There is no case for seed.