Gadenin日本語Get the appChoosing a method
The horizontal habit that makes this shrub worth growing also makes it easy to increase. The lowest tier often rests on the soil, and where a branch stays in contact with damp ground it puts out roots without being asked. That gives you a method with almost no failure rate, at the cost of waiting a year.
Cuttings are quicker and give you more plants at once, but they need the wood taken at the right firmness. Seed is only relevant for the fruiting lacecap forms, since the fully double snowball forms are sterile and never produce a viable seed. Even where seed is available, it is slow and unpredictable and rarely worth it in a garden.
| Method | When to do it | Time to a planting sized plant |
|---|---|---|
| Simple layering | Spring, on a low horizontal branch | About a year to sever, two to plant out |
| Softwood cuttings | Early summer, on flexible new growth | Roots in three to five weeks; plant out the next year |
| Semi-ripe cuttings | Late summer, when the base of the shoot has firmed | Roots by autumn; grow on through one full season |
| Hardwood cuttings | Dormant season, on ripened wood | Slow and less reliable on this species |
| Seed | Autumn, from lacecap forms only | Two years to germinate; sterile forms set none |
Layering, the method that barely fails
Pick a young flexible branch on the lowest tier that can be bent down to the soil without straining the fork. In spring, loosen a patch of ground under it and work in some compost. About a foot (30 cm) back from the branch tip, nick the underside of the bark with a clean knife, then pin that section down into the loosened soil with a wire staple or a stone, and bend the last few inches of the tip upwards so it stands clear.
Cover the pinned section with an inch or two (3 to 5 cm) of soil, water it, and then largely forget it. Keep the spot from drying out through the summer. By the following spring there will usually be roots, which you can test by tugging gently: a layer that resists is rooted.
Sever the connection to the parent on the parent's side of the rooted section, and leave the new plant in place for another full growing season before lifting it. Lifting immediately after severing is the commonest way to lose an otherwise successful layer, because the new root system cannot yet support the top.
You will often find this has already happened by itself under an old plant. Feel along the lowest tier for a branch that has anchored into the ground and check for roots. If they are there, you can sever it straight away and skip the whole procedure.
Taking cuttings
Both softwood and semi-ripe cuttings work well. Softwood, taken in early summer from growth that is still flexible, roots fastest but wilts within minutes if it dries out. Semi-ripe, taken in late summer from shoots that have firmed at the base but are still soft at the tip, is more forgiving and is the safer choice if you cannot give the cuttings constant attention.
- Collect early in the morning Take shoots while they are full of water, before the sun is on the plant. Drop them straight into a sealed bag with a little moisture and keep them out of direct sun until you can prepare them.
- Avoid flowering wood and beetle shoots Choose non flowering side shoots from healthy growth. Discard any shoot with rows of raised brown pits near the tip, because those are beetle egg cavities and you would be propagating the pest.
- Trim to four to six inches (10 to 15 cm) Cut cleanly just below a leaf joint, remove the lower leaves, and halve any remaining large leaves across their width to cut water loss while leaving enough surface to feed the cutting.
- Dip the base and insert Dip the cut end in rooting hormone, then push the cuttings into free draining compost mixed roughly half and half with grit or perlite, deep enough to stand up on their own and spaced so leaves do not touch.
- Keep humid, bright and out of direct sun Use a propagator or a clear cover, and give bright indirect light. Bottom heat around 68F (20C) speeds rooting noticeably. Vent daily to stop gray mold building up.
- Test after three to five weeks Tug very gently. Resistance means roots. Then increase ventilation over a week or two before removing the cover entirely, so the cuttings harden rather than collapse.
- Record what you took and when Label each batch with the date and the wood stage, soft or semi-ripe. After two seasons those labels tell you which stage works in your own conditions, which no general advice can.
Growing the young plants on
Pot rooted cuttings individually once roots show at the drainage holes, using ordinary potting mix, and keep them in a sheltered spot out of strong sun and wind for their first season. Overwinter the first winter with the pots protected from freezing solid, because a young root system in a small pot is far more exposed than the same plant in the ground.
Do not shape them early. It is tempting to trim a leggy young plant into something bushier, but the tiered structure develops from long unbranched extensions and cutting those off delays the habit by years. Let the plant run, and remove only dead or damaged growth.
Expect three to five years from a rooted cutting to a plant that flowers meaningfully, and longer before the horizontal layering is obvious. Plant them out at their final spacing rather than close together with a plan to thin later, because a snowball moved once it has spread rarely re-establishes its shape.