Why Is My Radish Plant Wilting and Dying?

Radish plants that wilt when the soil is moist — when drought is not an obvious explanation — have a root problem. The root is either damaged, diseased or being eaten, and the plant is unable to supply its leaves with the water and nutrients it needs. Diagnosing the root problem promptly matters — since radish matures quickly, a wilting plant is effectively a lost plant and you want to understand why before the same thing happens to the next sowing.

Check the root immediately

Pull up the wilting plant and examine the root closely. The symptom pattern on the root tells you which problem you have. Tunnels running through the root with small creamy-white maggots = cabbage root fly larvae. Irregular swollen galls replacing normal root structure = clubroot. Soft, brown, mushy tissue = root rot from overwatering. No root at all (snapped at the base) = slug damage at the stem base, just below soil level.

Root maggot (cabbage root fly)

Tunnels from cabbage root fly larvae are the most common cause of wilting in young radish that is otherwise apparently well-grown. The larva bores through the developing root, causing rapid wilting as the root can no longer function. There is nothing to do for the affected plant; prevent future damage with row cover from the moment of sowing. See the root maggot guide for full details.

Root rot from overwatering

Waterlogged soil causes roots to die from oxygen deprivation and secondary fungal attack. The soil may appear moist even as the plant wilts because the roots are dead and non-functional. Improve drainage, reduce watering frequency and ensure the growing bed has adequate drainage. Allow the top 3–4 cm to dry between waterings.

Slug damage at the stem

Slugs feeding just below the soil surface sever the plant stem cleanly. If the plant collapses at soil level and the root appears clean-cut at the base, slugs are responsible. Apply ferric phosphate pellets or nematodes and protect subsequent sowings.