Slightly larger than warabi ferns, they grow up to 3 feet (1 metre) tall. The plants do well in both shade and full sun, but prefer moist soil by ponds, streams, and rivers. They are hardy down to -4 F (-20 C) and will stay evergreen year round where the winters are mild.
Cheap zenmai being sold may actually be yam runners.
Zenmai fiddleheads are sold packed in water. Starch can be made from the rhizome.
Simmer whole to best preserve taste.