Gadenin日本語Get the appTake the plantlets that are ready
The small plants on the ends of the runners, often called spiderettes or babies, are complete plants waiting for somewhere to grow. Look at the underside of the base of one: if you can see the stubby brown or white nubs of root initials, it will root quickly. A plantlet with a smooth flat base and only two or three tiny leaves is not ready yet and will sit and sulk.
Wait until a plantlet has four or five leaves of its own and is at least two inches (5 cm) across. Leaving them on the runner does the parent no harm, so there is no hurry, and a plantlet that has been out on the runner for a month roots faster than one taken early.
| Method | What you need | Time to root | Best for |
|---|---|---|---|
| Layering while attached | A pot placed under the runner | Two to three weeks | The most reliable, no risk to the plantlet |
| Straight into compost | A small pot of damp compost | Two to four weeks | Several plantlets at once |
| Rooting in water | A glass and a few days' patience | One to two weeks | Watching the roots form |
| Dividing the parent | A mature clump and a knife | Immediate | A pot bound plant you want to split |
The warm half of the year is the window. Below about 64F (18C) rooting slows to a crawl and cut bases are far more likely to rot than to root.
Layering while it is still attached
This is the method that essentially cannot fail, because the plantlet stays connected to the parent and keeps being fed while it makes its own roots. It is what the plant does naturally where it grows on the ground.
- Set a small pot underneath Stand a three inch (8 cm) pot of damp compost next to the parent, close enough that the runner reaches without being stretched tight.
- Pin the plantlet down Rest the base of the plantlet on the surface and hold it with a bent paperclip or a hairpin so it is in firm contact with the compost. Do not bury the crown, only the base.
- Keep the surface damp Water the small pot lightly every few days. Roots enter the compost within two to three weeks and you will feel resistance if you tug the plantlet gently.
- Cut the runner last Once it resists a gentle tug, cut the runner close to the new plant. Only cut after it is rooted, never before.
Straight into compost, or into water
If you would rather detach first, both work. Compost gives a stronger plant sooner; water is easier to judge because you can see exactly what is happening, which makes it the better choice if you have not done this before.
- Into compost Cut the plantlet off with an inch (2 cm) of runner attached, press the base into damp free draining compost so the root nubs are just covered, and keep it bright, warm and out of direct sun.
- Into water Stand the plantlet in a glass so only the very base sits in water and the leaves stay clear of it. Change the water every two or three days. White roots appear within a week or two.
- Pot up before the roots get long Move it into compost once the roots are one to two inches (3 to 5 cm). Water roots are structurally different from soil roots, and a plantlet left in water for months struggles badly when it is finally potted.
- Keep the humidity up for the first fortnight A clear bag loosely over the pot, opened daily, stops a newly potted plantlet drying out before its roots can supply it. Remove it once new growth starts.
Three or four plantlets in one pot make a full looking plant far sooner than one on its own, and they grow together without competing for years.
Dividing an established plant
A mature clump is made of several crowns sharing one mass of thick roots, and it can be split when it has filled its pot. Do this in spring or early summer so both halves re root while the plant is growing hard.
Slide the plant out and shake or wash off enough compost to see where the crowns separate. Pull them apart by hand where you can, and use a clean knife where the roots have knitted together. Keep a good share of the white storage roots with each piece and pot them individually into a pot only slightly larger than their roots.
Cut off any brown, soft or hollow roots as you divide, and leave the cut surfaces to dry for an hour before potting. Water once after potting, then keep the compost only just damp for a fortnight.
Why a plantlet fails to root
There are only a few reasons and they are all easy to check. It was taken before the root nubs formed. It was taken in the cold half of the year. It was buried too deep, so the crown rotted before the roots grew. Or it was kept soaking rather than damp and the base turned brown and soft.
Note the date you take plantlets and how long each one took, because a season's worth of that record tells you the point in your own year when they root fastest. In most homes it is the second half of summer, when the plantlets are well developed and the room is still warm.