Gadenin日本語Get the appThe one rule: every piece needs a node
A dieffenbachia roots from nodes, the faint rings that circle the cane where a leaf was once attached. A piece of stem carrying at least one node will make roots and, from a dormant bud at that node, a new shoot. A leaf pulled off on its own will not, however long you leave it in water: it has no bud and no node, so it can never become a plant. That single fact explains most failed attempts.
Beyond that, propagation is easy and forgiving as long as it is warm. Take cuttings in late spring or summer when the room is reliably above 70F (21C). Below about 64F (18C) the cut end rots faster than it roots, and a cutting taken in winter usually sits doing nothing for two months and then goes soft.
Wear gloves for all of this. Fresh cut surfaces bleed sap that burns skin, eyes and mouths, and cuttings sitting on a windowsill are within easy reach of a curious cat. Keep the whole operation somewhere pets and children cannot get to.
Which method for which plant
What you do depends on the shape of the plant you are starting from. A leggy plant on a bare cane gives you both a tip cutting and several cane sections from the same operation, which is why cutting back and propagating are really one job. A plant that has thrown a second shoot from the base can simply be divided at the next repot, which is the fastest route to a full-sized second plant.
| Starting point | Method | Roots in | Result |
|---|---|---|---|
| Leafy top of a tall plant | Tip cutting, 4 to 6 in (10 to 15 cm) | 3 to 6 weeks | An instant, full-looking plant |
| Bare cane below the top | Cane sections, 2 to 3 in (5 to 8 cm) | 6 to 10 weeks | Small plants, slower to look good |
| Two crowns from one rootball | Division at repotting | Establishes in 2 to 3 weeks | A mature plant straight away |
| A tip you want roots on before cutting | Air layering on the standing cane | 4 to 8 weeks | No rooting risk, parent stays whole |
Taking and rooting a tip cutting
This is the method to use first. It gives the best-looking result quickest, because the cutting already has full-sized leaves, and it roots faster than anything else on the plant.
- Cut a top with four or five leaves Take 4 to 6 inches (10 to 15 cm) of stem below the lowest leaf you are keeping, cutting half an inch (1 cm) under a node with a clean sharp blade.
- Strip the lowest leaves Remove any leaf that would sit in water or under the compost surface. Buried or submerged leaves rot and take the cutting with them.
- Let the cut callus Stand the cutting somewhere warm and shaded for two to four hours until the cut face is dry to the touch. Skipping this step is the commonest cause of a rotted base.
- Set it in water or in compost In water, submerge one node and change the water every three days. In compost, bury the node an inch (2.5 cm) deep in a free-draining mix kept just damp, and support the cutting with a stick so it does not rock.
- Keep it warm, bright and out of sun 70 to 80F (21 to 27C), bright indirect light, high humidity. A clear bag over the top helps, opened for a few minutes daily so it does not go moldy.
- Pot up at the right moment Move a water-rooted cutting into compost when its roots are 1 to 2 inches (3 to 5 cm) long. Longer water roots are brittle and break on transfer, which sets the plant back a fortnight.
Rooting sections of bare cane
The bare stem left over after you cut a leggy plant down is not waste. Cut it into pieces 2 to 3 inches (5 to 8 cm) long, each with at least one node, keeping track of which end was uppermost. Cane sections planted upside down will not shoot, and once the leaves are off there is nothing to tell you which way is up unless you mark them as you cut.
There are two ways to set them. Lay each section horizontally on the surface of damp compost and press it in until it is half buried with the node facing upward; or push it vertically into the compost, lower end down, leaving the top third exposed. Both work. Horizontal is a little more reliable because the buried half stays evenly moist while the exposed half cannot sit wet.
Then be patient. Roots come first and are invisible, and a shoot may take six to ten weeks to break. Do not keep lifting the pieces out to look. A section that is still firm when you squeeze it is still alive and still working; a section that has gone soft or hollow is finished and can be thrown away.
Mark the top of every section with a slanted cut and the bottom with a straight one before you separate them. It takes seconds and it removes the one mistake that wastes ten weeks.
Air layering when you cannot risk the cut
If the plant is a large old specimen and you do not want to gamble the top on rooting, air layer it instead. Choose a point on the cane below the leaves, cut a shallow upward slit a third of the way through, wedge it open with a matchstick, wrap the wound in a handful of damp sphagnum moss and enclose that in plastic tied at both ends.
Roots appear in the moss in four to eight weeks and you can see them through the plastic. Once there is a decent ball of root, cut the cane off below the new roots and pot the whole thing up, moss and all. The parent stump then reshoots exactly as it would after an ordinary cut, so you end up with the same two plants, without ever having a rootless cutting to worry about.
Why cuttings fail, and what to write down
Nearly every failure comes down to four causes: the room was below 64F (18C), the piece had no node, the cut was buried wet without being allowed to callus, or a cane section went in upside down. None of these is a matter of skill and all four are avoidable.
Record the date each cutting was taken, which method you used, whether it was a tip or a cane section, and the date you first saw a root or a shoot. Note how many of each batch took. After a single season those numbers tell you the honest rooting time in your own house and which method works best on your windowsill, which is worth far more than any general figure.