Long bare stems and pale new leaves
Stretching is a plant reaching for a window that is too far away. What etiolation looks like, why the stretched growth never shrinks back, and what to do.
What it usually is
1 Not enough light
| How to tell | Measure the gap between one leaf and the next on new growth against the same gap on older growth. If the new gaps are longer, the plant is stretching. New leaves will also be smaller and paler than the ones below them, and the whole plant leans towards the window. |
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| The fix | Move it to the brightest position you have that suits the species, and turn the pot a quarter turn every week so it grows evenly. Growth already stretched will not shorten, so cut back to a leaf joint in spring and let the new growth come in tight. |
2 Winter, and a shorter day
| How to tell | The stretching began in autumn on a plant that was compact all summer, in a spot that has not changed. The daylight has halved and the plant is doing the best it can with it. |
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| The fix | Move it nearer the window for the winter, take the net curtain down, and clean the glass. Water less while it is stretching, because a plant in poor light uses less. Move it back in spring if the summer sun would be too strong there. |
3 Too much nitrogen
| How to tell | Soft, floppy, oversized pale growth on a plant that is fed often, rather than thin stretched growth reaching in one direction. The stems bend under their own weight. |
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| The fix | Stop feeding for two months and water normally, which washes some of it through. Then feed at half the strength on the bottle and no more than the label says, which is almost always less than people give. |
Through the year. Stretching in the dead of winter is the plant surviving a dark month and is worth tolerating; the same stretching in June means the spot is genuinely too dark and will not improve on its own.
Etiolation is the proper word for it and the mechanism is simple. A plant in poor light spends what it has on getting taller rather than on making more leaf, because height is the only strategy that might reach the light. The stem between leaves lengthens, new leaves come out smaller, colour fades because the plant cannot afford to build much pigment, and the whole thing leans towards the brightest thing in the room.
The first useful thing to know is that this is entirely a light problem. Feeding a stretched plant does not fix it and often makes it worse: more nitrogen produces more soft growth for the same light. Watering it more does nothing except risk the roots. The only fix is more light or less plant.
The second useful thing is that stretched growth never shortens. The stem has laid down its cells and that is that. So the repair is done with secateurs rather than with hope. In spring, cut the stretched stem back to just above a leaf joint, and the plant will branch from below the cut into the better light you have by then given it. Many houseplants, pothos, tradescantia and philodendron among them, root readily from the piece you removed, so a leggy plant is also a free second plant.
Judging the light honestly is the hard part. Stand where the plant stands, at midday, and hold your hand up. A crisp shadow means good light. A soft shadow with fuzzy edges means moderate. No shadow at all means the spot cannot support most plants, whatever the label said. Distance matters more than people expect: light falls away sharply with the square of the distance from the window, so a plant a metre back is getting a small fraction of what a plant on the sill gets.
A last note about succulents. In poor light they stretch dramatically, the rosette opening out into a pale tower, and they also lose their red and purple colouring, which is a stress pigment made in strong sun. Both are the same message. Move them to the sunniest sill in the house, and expect the old stretched growth to stay stretched while the new comes in tight.
Entries that name it
What the journal says about this symptom on each plant.
| African violet | Too little light, which stretches the stalks and lifts the rosette off the compost. Move it brighter. An old plant with a bare neck can be cut off below the leaves and re-rooted as a cutting. |
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| Aloe vera | Not enough light. Move it to the brightest window you have. The stretched growth stays stretched, but new leaves come in tight and upright again. |
| Arrowhead vine | Too little light, or a plant left unpinched. Move it brighter and pinch the growing tips every few weeks so it branches. |
| Basil | Not enough light. Move to a sunnier position and pinch out the tips to encourage bushy growth. |
| Blushing philodendron | Too little light, or nothing to climb. Move it brighter and give it a moss pole. The leaves get larger as it climbs. |
| Century plant | Not enough light, so the rosette opens out and the leaves go soft and pale. It needs full sun and there is no substitute. A plant grown soft never firms up again. |
| Chinese money plant | Not enough light. Move it brighter and turn the pot a quarter turn each week so it grows evenly rather than leaning. |
| Coriander | Too little light, or seedlings crowded together. Thin to about 15 cm apart and move it into better light. Crowded coriander bolts sooner as well as growing thin. |
| Corn plant | Not enough light. Move it brighter, and cut the cane back in spring at the height you want it to shoot. |
| Croton | Too little light, giving a long bare stem with a tuft on top. Move it brighter and cut the stem back by a third in spring. It breaks new shoots from below the cut. |
| Dragon tree | Not enough light. Move it brighter, and cut a tall bare stem back in spring at the height you want it to branch. |
| Dumb cane | Too little light, giving a bare stem with a tuft on top. Move it brighter and cut the stem back in spring. It shoots from below the cut and the top roots as a cutting. |
| Echeveria | Not enough light, which stretches the stem and opens the rosette. Move it to the sunniest place you have. Behead the stretched rosette in spring, let the cut callus, and root it as a cutting. |
| English ivy | Not enough light. Move it brighter and cut the long stems back by half in spring. It breaks new growth readily from old wood. |
| Fiddle-leaf fig | Too little light, which also causes the bare lower stem people complain about. Move it nearer the window and turn it a quarter turn each week. To fix an existing bare stem, cut the top off in spring and let it branch. |
| Gooseberry | Too much shade, which produces thin, stretched growth and a noticeably smaller crop than the same bush would carry in full sun. Move a container-grown bush to a sunnier spot where possible, or prune back overhanging growth from neighbouring plants that is shading it. A bush planted in the wrong spot from the start is worth relocating rather than persisting with. |
| Heartleaf philodendron | Not enough light, which stretches the gaps between leaves. Move it brighter and cut the long stems back to just above a leaf. It branches from the cut and fills out again. |
| Inch plant | Not enough light, which stretches the stems and drains the colour. Move it brighter and pinch the tips out regularly. The colour returns on new growth. |
| Jade plant | Not enough light. Move it to the sunniest window you have. Cut the stretched growth back in spring; it branches from the cut and the new growth comes in tight. |
| Ladyfinger cactus | Not enough light, so the stems stretch and go pale at the tips. Move it to the brightest window. The stretched section stays stretched, and the plant will thicken again above it. |
| Lavender | Shade, or years without pruning. Move it into full sun and prune every year after flowering. A plant that has gone woody cannot be cut back into bare wood and recovered. |
| Lucky bamboo | Too little light for the growth it is trying to make. Move it somewhere brighter but still out of direct sun, and cut the tall stem back to force side shoots. |
| Male fern | Too much shade combined with hungry soil under a greedy tree. Mulch with leaf mould each autumn and, if it sits under a conifer, move it. Very dry shade under evergreens beats even this fern. |
| Mini monstera | A long bare stem with small leaves, which is the same problem earlier. Cut it back to a node and root the top. It will branch from below, and the cutting roots in water in a fortnight. |
| Mint | The plant running to flower, or a pot that has exhausted itself. Cut the whole plant back to about 5 cm; it regrows within three weeks. Divide and repot every spring. |
| Oregano | Shade, or a plant that has not been cut back. Trim hard after flowering and give it the sunniest spot you have. |
| Parsley | Too little light, or seedlings left crowded. Thin to 20 cm apart and give it the brightest spot you have. Crowded parsley is thin parsley. |
| Petunia | Not enough light, or a plant that was never pinched out when young. Move it into full sun and shorten every stem by half. Pinch the tips of young plants once to make them branch from the base. |
| Polka dot plant | Not pinched, and probably not bright enough either. Pinch the growing tips out every few weeks from the day you buy it. It branches readily and looks completely different for it. |
| Potato | Shoots grown in the dark before planting, or a plant in shade. Chit the seed potatoes in a cool light place so the shoots come short and green rather than long and white. |
| Purple heart | Long bare stems with leaves only at the tips. Pinch it back hard. Every piece you remove roots in water in a week, so a leggy plant is really a free plant. |
| Purple shamrock | Not enough light. Move it brighter. Cut the stretched growth away and the new leaves come in short and deeply coloured. |
| Ripple peperomia | Too little light, so the stalks lengthen and the ripples flatten. Move it to a brighter spot out of direct sun. The next leaves will come back corrugated. |
| Rosemary | Shade, or years without a trim. Move it into full sun and shorten the shoots by a third each year after flowering, staying in growth that still has leaves on it. |
| Rubber plant | Not enough light, which also leaves the lower stem bare. Move it brighter, and in spring cut the top out above a leaf node so side shoots break lower down. |
| String of hearts | Long bare stretches of stem between leaves, which means too little light. Move it brighter. Cut the bare strands back and lay them on compost, because every node will root and thicken the pot up. |
| String of pearls | Not enough light, which stretches the gaps between the beads. Move it somewhere brighter with a few hours of gentle direct sun. Cut the bare strands back and pin the cuttings into the same pot. |
| Sunflower | Sown too early indoors and kept in poor light before planting out. Sow later and directly into the ground where possible. A stretched seedling never makes a sturdy stem, however well you stake it. |
| Thyme | Not enough sun, or a plant that has gone woody with age. Trim by a third after flowering to keep it compact, and replace a woody plant every three or four years. |
| Trailing ice plant | Not enough sun, so the stems stretch and the mat opens up in the middle. Move it into full sun. Cut the long stems back and push them into gritty compost, where they root within a few weeks. |
| Tree aeonium | Not enough light, so the stems lengthen and the rosettes flatten out. Move it into full sun. Cut the top off a leggy stem, let the cut dry for a few days and root it in gritty compost. |
| Umbrella plant | Not enough light. Move it brighter and cut it back hard in spring. It branches readily from old wood, which few houseplants do. |
| Wax plant | Not enough light, or the long leafless searching stems the plant makes naturally. Move it brighter. Leave the bare questing stems alone; they are looking for something to climb and will leaf up once they find it. |
| Weeping fig | Too little light. Move it brighter, and prune the longest shoots back by a third in spring so it branches lower down. |
| Yucca | Not enough light, giving long soft leaves and a stretched cane. Move it to the sunniest position you have, and cut the cane back in spring to force a tighter head of new growth. |
| Zebra haworthia | Not enough light, so the rosette stretches and opens out. Move it to a brighter windowsill. The stretched growth stays stretched; the new growth comes back tight. |
| ZZ plant | Too little light for the growth the plant is trying to make. Move it somewhere brighter, still out of direct sun. New stems then come up shorter and hold themselves upright. |
Questions from the margin
- Why is my plant growing tall and thin?
- It is reaching for light. When a plant cannot get enough, it spends what it has on height rather than on leaves, so the stem between leaves lengthens and the new leaves come out smaller and paler. The proper word is etiolation, and the only cure is more light.
- Will leggy growth go back to normal?
- The stretched part never shortens; the cells are already made. Move the plant somewhere brighter and the new growth will come in tight, then cut the stretched stem back to a leaf joint in spring and let the plant rebuild from there.
Checked against RHS, Houseplants: light levels; University of Vermont Extension, Etiolation in houseplants.