Wasabi leaves drying up and dying

Cress    Syracuse, NY

The leaves on my wasabi plant are progressively drying up and dying. I had the plant near a window with partial sun which may have led to its decline (too much light), but it's been out of the sun for a week in a spot with indirect light and has gotten worse since then. The dying leaves always initially have black spots on their stem, mostly near the leaf, which gets worse as the leaf dies. It's been very warm during the day (~80 F), but I would expect this to only cause some wilting, not die-off. Is this the result of too much light, or could it be fertilizer? I also haven't checked the roots yet for rot.

I'm hoping someone knows a bit about wasabi because there is very little information available online. It's not a very common plant to be grown outside of Japan and Washington state.

Posted by: Matt (9 points) Matt
Posted: June 24, 2016


It looks like black leg disease caused by fungus Phoma wasabiae. The disease is favored by warm weather. The main symptoms are appearing of black spotting on the leaves, petiole, and stem surfaces initially. The fungus also spreads to vascular tissue. Later the leaves show irregular and circular spots, which eventually result in holes. As the disease progress the leaf veins become dark and leaves droop due to weakened vascular tissue. The disease eventually destroys the whole vascular system by causing necrosis.

This is very serious disease and mainly transmitted through infected planting materials. Remove the infected plant and destroy. Use healthy, disease free planting material.

Posted by: Dr. Ravishankar Narayana (11 points) Dr. Ravishankar Narayana
Posted: June 27, 2016

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