Gadenin日本語Get the appWhy it goes bare-legged
Given a few years, almost every aralia ends up as a tuft of foliage on top of a length of bare woody stem. This is partly natural: the plant sheds its oldest lower leaves as it extends upward. It is accelerated by anything that makes the plant shed leaves in bulk, so a specimen that has been moved several times, or that spent a winter too cold and too wet, gets there far faster.
The good news is that polyscias is genuinely forgiving of the knife. Unlike plants that only shoot from a live growing point, it breaks from dormant buds along old woody stems, so cutting well down into bare wood produces a flush of new shoots rather than a dead stump. Hard pruning is the standard fix and there is no gentler alternative that works.
You cannot fix a bare lower stem by feeding or by moving the plant into brighter light. Those measures improve the growth from here on, but the section of stem that has already dropped its leaves will only releaf if you cut back into it.
When to cut
Prune in the warm growing months, when the plant has enough light and warmth to push new shoots quickly. A cut made while the plant is growing strongly typically shows the first buds swelling in two to four weeks. The same cut made in midwinter can sit there for months on a bare stump, and every week it sits there is a week the roots have nothing to feed.
There is one important exception to the timing rule: do not prune a plant that is already stressed. If it has just been moved, has just dropped most of its leaves, or has just been repotted, wait. A plant recovering from one shock should not be given a second one. Let it releaf, let it settle for a month or two, and then cut.
| Situation | Prune now? | Reason |
|---|---|---|
| Healthy plant in the warm months, bare lower stem | Yes, cut hard | Fastest, strongest regrowth |
| Healthy plant, only slightly untidy | Light tip trim only | Encourages branching without a long bare period |
| Plant that has just been moved and is dropping leaves | No, wait | Let it stabilize for a month or two first |
| Plant repotted within the last month | No, wait | Roots and shoots should not be cut in the same season |
| Dark, cold conditions, short days | No, wait for warmth | Cuts sit dormant and stems can die back |
| Stem dead, soft or blackened | Yes, remove immediately | Dead wood is a route for rot regardless of season |
Making the cuts
Work with clean, genuinely sharp pruners or snips. Aralia stems are woody and a blunt blade crushes them, leaving a ragged wound that dries back. Wipe the blades with alcohol before you start, particularly if you have been cutting anything else.
- Decide the finished height first Look at the plant and pick the height you want the new foliage to start from, then plan to cut a few inches below that, because new shoots emerge below the cut. Cutting back by a third to a half of the total height is normal, and on a badly bare specimen taking it down to six or eight inches (15 to 20 cm) of stem is acceptable.
- Cut just above a node Find the slight ridge or old leaf scar on the stem and cut about a quarter of an inch (5 mm) above it, at a slight angle. Buds break from just below the cut, so cutting at a node gives you shoots exactly where you want them instead of a length of dying stem above the nearest bud.
- Shorten the tallest stems first, then balance On a multi-stemmed plant, cut the tallest and barest stems back hardest and leave the shorter ones longer. This keeps some foliage on the plant while it regrows and gives you a tiered shape rather than a flat-topped one.
- Thin out crossing and inward stems Remove any stem that rubs another or grows back through the center of the plant, cutting it right back to its origin. Air moving through an open framework is the cheapest control you have against spider mites in fine foliage.
- Stop watering as heavily afterwards A plant with a fraction of its former foliage uses a fraction of the water. Keep the compost barely moist until new shoots appear, then return to normal. More hard-pruned aralias are lost to rot in the weeks after cutting than to the cut itself.
Do not seal the cuts with anything. A clean cut on a dry stem callouses over on its own, and wound paints simply trap moisture against the wound.
Shaping, pinching and what not to cut
Between hard prunings, the way you keep an aralia dense is by pinching. Take out the soft growing tip of a shoot with your fingers once it has extended a few inches, and the shoot will usually break into two below the pinch. Doing this routinely through the growing season is what produces a full plant, and it costs nothing in appearance because you are removing an inch (2.5 cm) at a time.
There are a few things not to cut. Do not take off healthy foliage that is doing the work of feeding a recovering plant, do not remove more than about half the plant in one session, and do not repeatedly trim the same stem back into old wood without giving it a full season of recovery in between. Green leaflets are assets during the regrowth period, not clutter.
| Cut | Verdict | Note |
|---|---|---|
| Soft growing tip of an extending shoot | Pinch freely | Produces branching, no bare period |
| Bare woody stem below the foliage | Cut hard in warm months | Shoots break from old wood in two to four weeks |
| Stem crossing through the center | Remove at its base | Improves airflow and light penetration |
| Healthy leafy branch on a recovering plant | Leave it | The plant needs the foliage to rebuild |
| More than half the plant at once | Avoid | Roots outnumber shoots badly and rot risk rises |
| Dead or blackened stem | Remove to live tissue | Cut back until the cut face is clean and pale |
Keep a note of each cut
Write down the date of every hard prune, how far back you cut, and the date you first saw new buds break. Add which stems you cut and roughly how tall the plant was before and after. On a plant that regrows over months rather than weeks, memory is not good enough to tell you whether this year is going normally.
The interval between the cut and the first new shoot is the most valuable number in that record. If your notes say three weeks last time and it has now been seven, something has changed at the roots or in the temperature, and you can go looking for it instead of waiting hopefully. Over several years the notes also tell you how often this particular plant needs cutting back, which is usually far more predictable than it feels at the time.
Photograph the plant on the day you cut and again when new shoots appear. Two pictures a few weeks apart make the recovery obvious in a way that a bare stem in front of you never does.