Waterlogging

also called Water logging

Plants drowning in saturated soil, wilting and yellowing even though the ground is soaking wet.

Disorder No cure Doesn't spread

What you'll see

Wilting and yellowing while the soil is clearly wet — the giveaway that this is not drought
Water sitting on the surface or the ground squelching underfoot long after rain
Leaves yellow, drop, and growth stalls; soft new shoots may collapse
A sour, rotten-egg smell from airless soil, sometimes with a bluish-gray layer when dug
In containers, compost stays sodden and never dries between waterings

Why it happens

When soil is saturated, water fills the air spaces the roots need to breathe. Starved of oxygen, the roots stop working and begin to die, so the plant cannot take up water and wilts even though it is standing in it. This is the drowning itself — the root and crown rots that so often follow are a separate, secondary problem.

Brought on by prolonged rain on heavy clay or compacted ground, high water tables, blocked drainage, and pots left standing in saucers of water. Winter and early spring, when growth is slow and evaporation low, are the danger period.

Treating it

Ease standing water away by spiking or channelling, and stop all watering of affected pots
Lift container plants out of saucers and stand them on feet to drain freely
Once soil drains, mulch and hold off feeding until roots recover
Lift and replant small treasures into free-draining conditions if the site cannot be improved

Keeping it away

Improve heavy soil with plenty of organic matter and grit to open up drainage
Avoid walking on or working wet soil, which compacts it and makes matters worse
Plant on ridges, mounds or raised beds where the water table is high
Use free-draining compost and pots with good holes, and never leave them sitting in water

Who gets it

Few plants tolerate it, but Mediterranean herbs, silver-leaved plants, most fruit trees and alpines are quickly killed, while bog and marginal plants shrug it off.