Sunnibel,
I did some online research about your problem, and as far as i can tell they mention no root swelling like a beet. My guess is you may have one plant with a genetic defect, or it might by just a simple case of club root. How is the plant other then the deformed (beet like) root? If you have plenty of plkants that are doing fine, my suggestion would to be pull the plant. (Im not sure that club-root is transferable from one plant to another) But i wouldnt take any chances. Hope this helps. There is alot out there about mizuna so not to hard to find out, i only glanced 30 or so sights.

Are you sure it's not a nearby weed, or a beet seed that got in with your mizuna?

nygardener: yup, I'm sure! It's been there for a couple of month now and this swelling just happened recently. Also, it is a purple-stemmed mizuna and hard to mistake for anything else. And I actually did not grow beets this spring. :)

gardenman101: Clubroot, eh? I'll have to dig out my garden book and read up on that again, but vague memory says that it is something other brassicas get, so maybe that is it. The only thing that makes me wonder if it is an interesting mutation instead is that it is perfectly round and has pushed out of the ground exactly like a turnip... OK, writing that sparked me to look and a turnip is Brassica rapa and mizuna is... Brassica rapa (japonica). Coincidence? I'm still going to read up on clubroot first.

Thanks guys, for thinking about my question... I did get the idea that this isn't common since it took a while for anyone to answer.

Cheers!

you may have an interesting genetic variation, as others have said. Save the seeds and replant them, you may end up making money.

Its turnip heritage is just coming out, no doubt. I've not grown it enough to really know. I had some this spring, it was quite nice and was good in salad when young, but bolted quickly.

I say let it go to seed and grow some out and see what you get.

That's what I was starting to think, too... of course I'd have to wait until next year to see if it has any flavor. Still, it is just one little plant, actually smaller than the others (probably from making all that root and not so much leaf) so I'll probably give it a chance.

Denninmi, I'm surprised to hear that yours bolted quickly since I've been watching mine and thinking how nice it has been handling all of our heat with little bolting. It is one of the last remaining brassicas I have out there. I like it now blanched then sauteed with garlic and butter or olive oil. It has a nice mild but noticable flavor.

Mine's started bolting after daytime temps that have been oscillating wildly between the 60s and 90s. A new batch germinated in a couple of days, so I should have a fresh supply by the time the older plants are pulled.

The advantage of this plant is that turnip greens are too rough to eat, while mizuna is nice. If you can get both the greens and the root to be edible, people will be interested.

glib- yes, I know if I saw that in a seed catalog, I would be interested, for sure! I suppose the best bet is to take one of its own flowers and do my best to be the pollinator. I'm kinda large for a bee, but maybe I can manage...

As for the bolting, I wonder if we mean the same thing (I mean flowerhead formation)... It's just that while we recently had a big swing between the 68-70 a couple of weeks ago to 90+ the next week, that was not the first time it happened since the plants have been out. I'm just curious because it's only the 2nd time growing this for me and the 1st was last fall so heat wasn't an issue. I don't want to go around thinking it holds well in the heat only to find that this batch (or spring) is unusual...

Could it possibly be a cross between the mizuna and a kohlrabi? Maybe one of the seeds in your packet was a cross?

Sounds sort of cool!

I also have a Mizuna with a turnip-like root. It overwintered from last year and now has a large bulbous root. Its leaves are about 16 inches and thick stemmed. I'll see if I can get it to go to seed. Of the explanations given above I'm inclined to think it's a throw-back to its turnip heritage... but googling around has not shown any turnip parentage and I only see it described as an annual. Maybe a stray seed got into the package... if so so, what is it... I've googled Japanese Root Vegetables but have found nothing... to be continued.

I had forgotten about this. The seeds I saved from the plant with the bulb were sown, but got it in the frosts I had in spring. So I never did find out if they would make more bulbed mizuna plants. Hope you have better luck!

Mine did this too! I planted green and purple mizuna. Only the green looks like this, but it almost all of mine, not just one plant. Any ideas?

I have these too. It looks like a turnip. Wondering if you est them the same