Guides
Why is my plant wilting?
Wilting means the leaves are losing water faster than the plant can replace it. That can happen because the compost is dry, but also because wet or damaged roots cannot take water up. Feel the compost first.
Push a finger into the compost
If the compost is dry down to the second knuckle, start with underwatering. If it is damp or wet and the plant is still wilting, the roots may not be working properly. Do not add more water until you have checked the root-related causes below.
Work down the list
Too little water
- What you would see
- Leaves limp and hanging, compost dry and often shrunk away from the sides of the pot, the whole plant light when you lift it.
- The check
- Water it and come back in a couple of hours. If it was short of water, it should recover visibly in that time.
Midday heat
- What you would see
- A courgette, a hydrangea or a squash drooping heavily at two in the afternoon and standing up again by dusk, in damp soil.
- The check
- Look again after sunset before doing anything. Large soft leaves can lose water faster than roots supply it in full sun, then recover overnight. That is normal in some plants.
The roots have rotted
- What you would see
- Wilting on a plant whose compost is wet, lower leaves yellowing, and often a sour smell from the pot.
- The check
- Slide the plant out and look. Healthy roots are firm and pale. Rotted roots are brown, soft and strip between your fingers. A plant with badly damaged roots wilts even when the pot is wet.
Water is running past the root ball
- What you would see
- A plant that wilts within a day of watering, with water appearing in the saucer almost as soon as you pour it.
- The check
- Stand the pot in water for half an hour instead. Compost that has dried hard repels water and sends it down the gap at the side, so the plant stays dry through every watering.
Root pests
- What you would see
- A plant that wilts, recovers overnight, then stops recovering, and finally lifts out of its pot with very few roots left.
- The check
- Knock it out of the pot. Fat white C-shaped grubs with a tan head are vine weevil. Grey insects under white waxy powder are root aphids. Both are hidden below the compost, so leaf sprays will not reach them.
Waterlogged soil
- What you would see
- Outdoor plants wilting in the wet, worst in a hollow, along a low line or wherever footprints hold water.
- The check
- Dig a hole a spade deep and see whether it fills with water. Roots in saturated soil suffocate and stop working, so the plant can wilt even in wet ground.
It has just been moved
- What you would see
- A recently planted or repotted plant drooping for a week or two while the soil stays evenly damp.
- The check
- Count the days since it went in. Roots damaged in the move cannot supply the leaves until they regrow. Shade and steady watering are usually enough.
Vascular wilt
- What you would see
- One side of the plant wilting while the other grows on, lower leaves yellowing from the bottom up, and no rot at the stem base.
- The check
- Cut the main stem across and look at the ring of tissue just inside the bark. A brown or reddish stain there is a vascular wilt, and no amount of watering will help.
Brassicas wilting in the heat
- What you would see
- Cabbages, cauliflowers, swedes or wallflowers flat every afternoon in a bed that has grown brassicas before.
- The check
- Pull one up and wash the roots. Swollen, knobbly roots instead of a normal root system mean clubroot. The disease can persist in soil for many years.
Collar rot
- What you would see
- A shrub or young tree wilting over weeks in damp ground, often in the wettest part of the bed, with dieback in the crown.
- The check
- Pare a sliver of bark away at ground level. Dead brown tissue meeting healthy white tissue along a sharp line is Phytophthora, and the plant will not recover.
The stem has been damaged at the base
- What you would see
- A single plant collapsed while its neighbours stand, or a shrub that rocks in its socket when you push it.
- The check
- Take hold of the stem and pull gently. A seedling cut through at soil level is a cutworm or a slug, and a woody plant that moves at the base has been loosened by wind.
Still not sure which one it is? Photograph the leaf and compare it against the full library.