Waterlogging
Soil so full of water that roots run short of oxygen, which causes yellow leaves, wilting and root rot.
Also known as: Waterlogged soil, Wet feet
Symptoms and identification
Leaves turn yellow, droop and may drop, even though the soil is wet. Roots are dark, soft and smell sour, and plants are stunted. Water stands on the soil surface for a long time after rain.
Causes
Heavy clay soil, compacted ground, low spots, a high water table, flood, or watering too often. In pots, saucers or cache pots without drainage keep roots sitting in water.
Organic treatment
Stop watering and let the soil dry. Open up compacted soil with a fork, move plants to better-drained ground or repot them in fresh, free-draining mix after trimming rotted roots.
Prevention
Improve drainage with compost and grit, use raised beds on heavy soil, and choose plants that suit the site. Make sure pots have drainage holes and empty saucers after watering.
Chemical treatment (use with care)
No chemical treatment is needed. Fungicides do not fix waterlogged soil, and treating root rot only works if drainage is corrected.