Plant wasabi in spring. Set a start with the crown just above the soil, about a foot apart, in a hole that stays shaded.
Plant a start in spring, with the crown just above the soil
| Factor | Recommended | Avoid |
|---|---|---|
| When | Spring, once nights stay above about 30 F | Planting into frozen ground |
| Plant | A moist nursery start or rhizome piece with buds; soak it in cool water first | A dry, shriveled piece you stored more than a month |
| Depth | Roots covered; crown about half an inch above the soil, rhizome not buried | A deep hole that smothers the crown |
| Spacing | About 12 inches apart | Crowding so leaves stay wet against each other |
Wait until nights stay above about 30 F, then set wasabi in a shaded hole. Cover the roots, but leave the crown just above the soil so the thickened stem can sit in air. Buried crowns rot. [1] Shade and watering for the planted crop stay on How to Grow Wasabi.
When do I plant wasabi?
Plant in spring once nights stay above about 30 F. Frozen ground stalls the start. A mild fall window is possible in a frost-free shade bed, but spring is the usual home-garden time.
How to plant wasabi
Soak the start, set the crown high, and give each plant about a foot of room.
- Keep a mail-order start moist and cool until you plant, and do not store it more than about 30 days. Soak the roots in cool water and pull off damaged leaves.
- Dig a hole in loose, organic soil in deep shade. Set the plant so the roots are covered and the crown sits about half an inch above the soil. Do not bury the rhizome. [2] [3]
- Space plants about 12 inches apart. Water in with cool water so the mix settles around the roots, then keep the soil moist. Empty any puddle that sits on the crown.
How deep do I plant a wasabi start?
Cover the roots and leave the crown about half an inch above the soil. The rhizome needs to sit in air, not under a mound of mix.
What fails at planting
A buried crown rots. A start planted in afternoon sun scorches before the roots take. A dry piece stored for months rarely wakes.
Work organic matter into the hole so the mix stays moist and still drains. [4] If you only have seed, chill it first — see Growing Wasabi from Seed.
If the crown sits under soil, lift it so the thickened stem is just above the mix — a buried crown is the usual reason a new start rots.
FAQ
Can I plant a grocery rhizome?
Only if it is a fresh, living piece with buds, not a trimmed sushi stump. Most grocery wasabi is horseradish. Order a labeled start when you can.
Should I plant in spring or fall?
Spring is the usual window, once nights stay above about 30 F. Fall works only where frost will not kill a new start.
Related guides
Recommended plants
References
- [1] Utah State University Extension -
https://extension.usu.edu/yardandgarden/research/wasabi-in-the-garden - [2] Washington State University Extension -
https://wpcdn.web.wsu.edu/extension/uploads/sites/25/Wasabi-in-Pacific-NW-pnw0605.pdf - [3] One Green World -
https://onegreenworld.com/wasabi-growing-guide/ - [4] NC State Extension Gardener -
https://plants.ces.ncsu.edu/plants/eutrema-japonicum/
This note is part of Eutrema Guides.
More planting notes by plant are gathered in Planting Guides.
Updated: Reviewed by Bosquelle Editors