Gadenin日本語Get the appLeafless stems out of empty ground
The flowering habit is the whole character of the plant. Some weeks after the hottest part of summer has passed, usually as nights begin to cool in late summer or early autumn, a smooth stem pushes straight up out of ground that has looked bare for months. It carries no leaves at all. At the top it opens a rounded head of narrow-petalled flowers with wavy, recurved segments and long protruding stamens, most often in shades of pink, and the whole head has a distinct glitter in low sun.
Each stem lasts a remarkably long time, three to five weeks in cool autumn weather, and a clump does not open all at once. Stems come in waves over a month or more, so the display stretches well into the season when little else is flowering. This is the reason to give nerine a position you actually walk past.
The leaves arrive with the tail end of the flowers or shortly after them. That order confuses people who expect foliage first. Nothing is wrong: the bulb flowers on stored reserves from the previous winter's leaves, then produces the new leaf fan that will feed next year's flowers.
What actually triggers the flowers
Flower buds are set inside the bulb during the summer rest, not in autumn. Heat on the shoulders of the bulb through a dry dormant period is what ripens them, and the cooling nights at the end of summer are simply the signal that releases the stem. That single fact explains why nerine planted deep, watered in summer, or shaded by the leaves of neighboring perennials will grow well and flower badly.
It also explains the second requirement, which is congestion. A crowded clump has bulbs pressed against each other with their necks in the sun and very little cool moist soil between them, and it flowers freely. A newly spaced-out planting has the opposite conditions, and takes several seasons to build back up.
Why a healthy clump refuses to flower
When a nerine makes strong leaves and no stems, the bulb is not sick. It is being denied one of the conditions above. Work down this list in order; the first two account for most cases.
| Symptom or history | Likely cause | What to do |
|---|---|---|
| Divided or moved in the last year or two | Root disturbance, and bulbs no longer crowded | Nothing. Leave the clump entirely alone and expect flowers to return in the second or third season |
| Strong leaves, no stems, bulbs not visible at the surface | Planted too deep, so the bulbs never bake | Scrape soil away from the shoulders so the necks stand clear, or replant shallow after the leaves die down |
| Full sun in spring, shaded by neighbors in summer | Perennials or shrubs have closed over the bulbs | Cut back or move whatever overhangs the strip so summer sun reaches the soil |
| Bed irrigated or heavily mulched through summer | The bulbs never get a dry rest | Stop watering the strip from the time the leaves yellow until the stems appear, and keep loose mulch off the necks |
| Clump many years old, flowering slowly declining, bulbs pushing out of the ground | Genuine overcrowding at last | Divide once, immediately after flowering or as the leaves fade, then leave alone again for years |
| Very few leaves, small pale bulbs | Starved after the leaves were removed too early in past seasons | Let the foliage die down naturally and feed lightly through winter growth |
Dividing is what stops flowering, not what starts it
Gardeners transfer a habit from other bulbs and perennials, where a congested clump is a problem to be split. With nerine that instinct is exactly wrong. Splitting a crowded clump is the single most reliable way to stop it flowering, and the effect lasts two or three seasons while the pieces re-root and press back together.
Only divide when flowering has genuinely fallen away over several years and the bulbs have heaved themselves out of the ground in a solid raft. Even then, replant the divisions in tight groups rather than spreading them thinly, and accept that the display will pause. If you want nerine somewhere else, it is usually faster to plant new bulbs there than to take pieces from a clump that is flowering well.
Slugs and snails feed on emerging nerine stems and can shear off a bud at ground level overnight, which looks exactly like a bulb that failed to flower. Check the base of the stems in the first days after they appear, especially after wet weather.
After the flowers, and what to record
When a head finishes, cut or snap the stem off close to the base rather than pulling it, since pulling can loosen a shallowly seated bulb. Removing the stems stops the plant from putting energy into seed, which is worth doing simply because the leaves that follow have the whole winter's work ahead of them. Never remove the leaves at the same time.
The record that pays off here is a short flowering log: the date the first stem appeared, the date the last one opened, the number of stems, and one line on the weather of the preceding summer. Nerine responds directly to how hot and dry its rest was, so after three or four years those notes let you predict the season and, more usefully, show you which end of the clump is thriving and which is being shaded or watered by something you have not noticed.