Even cold-hardier (colder-hardy?) than tatsoi is Holland Greens, or 'Tyfon'.
'Tyfon' is supposed to take cold down to 10 degrees F without a problem,, but I've never tested that either. Of course, the seedlings have to be established before the plants can take weather down to 22 DEGREES BELOW FREEZING. And yet it doesn't seem to mind warm weather as most Brassicas do.
You can direct-sow 'Tyfon' 4-6 weeks before the last spring frost, or 8-10 weeks before the first fall frost. Or any time as a catch crop when a few square feet would otherwise lie idle.
Once it emerges, you should cut it every 20-35 days (it will cut-and-come-again 2-3 times) because the leaves can get hairy and tough when too old.
This makes it like other Asian Brassica greens, but even more so: the small leaves are tender and mild enough for salad, but when older, they benefit from steaming, boiling or fast frying.
'Tyfon' is a stabilized hybrid of two Brassica rapa sub-species, Chinese cabbage and stubble turnips. It is an OP variety now and you can save seeds for future crops.
It was originally developed as a cover crop for forage, so they bred ANY mustard taste out of it so that cows' milk wouldn't taste like Asian mustards. As a result, the taste is so mild that Americans will accept young leaves in salad. When cooked, the greens take on the flavor of anything they are cooked with.
One virtue of 'Tyfon' is that it is ridiculously productive, especially if you harvest one plant three times. Someone said it was THE green to grow if you had to feed the whole Red Army from one row.
I'm thinking of using it in soup as "lots o' greens", and mixing in a little Broccolo Spigarello or old Bok Choy leaves to give it more flavor.
Direct sow 1/2" deep. Thin to 6".
Germinates in 5-10 days at 40-85 F.
Prefers loose, well-drained soil but is not fussy.
I found my 'Tyfon' seeds at Nichol's Garden Nursery (VGR472)
https://www.nicholsgardennurse...
(Nichols also has a fancy Red Violet Tatsoi Hybrid
https://www.nicholsgardennurse...
