Horseradish: Armoracia rusticana

Saw it in the grocery store.  Noticed a couple of little green bumps obviously serving as potential grow points.  Why not?

Kept it in a tall glass, and put it outside in on a shaded porch.  Changed out the water if it got gross.  After a week or so, i found this little green growth:

Notice the water line

Eventually, the leaves flushed out:

I've noticed that compared to carrot, beet, rutabaga and others, horseradish root doesn't seem too vulnerable to water-rot.  I still need to change out the water, but the hard root seems unperturbed by submergence.

At a certain point, it becomes obvious that the root structure belongs in soil rather than pure H20.  Here it is transferred:

The leave margin curl seems to correspond precisely with this transfer.  Due to lowered average state of root moisture, there *will* be some transplant shock, and I eventually lost a couple of leaves.  It's also obviously a bit harder to keep watered.

I've kept it out of midday sun, and despite the supposedly slower growth .... one night it seemed to suddenly double in size:

It's already bigger than this

I'm not sure what my end goal is, but this definitely seems to have been worth the project effort.

Update:  yup, still growing a week later: