Yukina Savoy is a very delicious cold tolerant cooking green. It grows in a rosette, like tatsoi, but bigger, less shiny, more blistered. It survives down to 10°F (-12°C) outdoors, so is a good outdoor crop in late fall. Ours is doing so well this year that we started eating outer leaves in early October, planning to eat more later. We eat from the outdoor crop from mid-October until mid-December. Outdoors, we transplant them 12″ (30 cm) apart.
We have also transplanted some in our hoophouse (sown 9/15) to feed us in December and January. A second sowing (9/24) will feed us in January and February. It is fast-growing in the fall, taking 21 days to reach baby size, 45 days to full size. The plants grow quite large, we transplant them at 10.5″ (26 cm) apart. They grow 12″ (30 cm) tall.
In the spring (which comes early indoors) Yukina Savoy has the advantage of being somewhat heat-tolerant – it doesn’t bolt until the middle of March in there. Of course, we aim to have eaten it all before they get a chance to bolt.
For commercial sales, the whole plants are cut, gathered and fastened with a tie. For home use, you have the option of simply taking the leaves you want for immediate use, and letting the heart of the plant continue to make more growth.
The photo to the left shows the open-pollinated variety we used to buy from Fedco Seeds, but sadly they no longer have that. Instead we bought a hybrid Koji from Johnnys Selected Seeds. Koji claims to be “attractive, upright, and earlier maturing than Yukina Savoy, which it replaced.” I think the “more upright” and possibly the “earlier maturing” parts are true. Attraction is in the eye of the beholder. I think Koji is less cold-hardy and less blistered than the OP type, shinier, and with greener stems.
I’ve found the OP one at Kitazawa Seeds, where it is classified as Chinese cabbage, loose head type. It’s a Brassica Rapa Pekinensis Group, for those considering saving seed.
Both types are delicious, and easy to cook.
We had been including Yukina Savoy in our hoophouse bed which has nematodes, thinking it is Brassica Juncea, which has some resistance to root knot nematodes. Back to the drawing board, on that plan!
Tatsoi is a smaller, shiny dark-green leafed plant with whiter stems. The leaves are sometimes described as “spoon-shaped” – the white stem is the spoon handle and the leaf blade is the bowl of the spoon. The plant grows as a flat rosette if it has plenty of space, but more upright if crowded as in the photo above. The flavor is milder than Yukina Savoy. In the fall, it takes 21 days for baby salads; 45 days for cooking. We don’t plant tatsoi in spring, as it would bolt before growing in our “Instant Summer” climate.
Tatsoi is also very cold-tolerant, similarly hardy to 10°F (–12°C). We no longer grow this one outdoors, because Yukina Savoy is bigger and easier. We prefer our small plants be in the hoophouse, where there are almost no weeds, and we don’t mind spending longer harvesting in winter. (More tatsoi per bucketful than Yukina Savoy = more time).
We direct sow in the hoophouse on Sept 6, one of our first fall hoophouse sowings. We sow rows 6″ apart, knowing they will get crowded. We thin into salad mixes, leaving some plants to mature at 10″ (25 cm) across for cooking greens. Tatsoi also transplants easily – I’d probably go for 6″ (15 cm) spacing if transplanting. The first sowing feeds us from 10/20 – 12/31, with thinnings for salad from Oct 8.
We make a second hoophouse sowing on November 15. This one takes 8 days to germinate. It will feed us from 2/12-3/12 (thinnings 12/27-1/21). So, altogether, we have full size tatsoi to harvest from October 25 – March 5. We usually either thin out the plants, or cut outer leaves until we see the plants are about to bolt, then cut heads.
Kitazawa Seeds have a Red Tatsoi, a Red Violet tatsoi/pak choy hybrid, with an upright habit, and several tatsoi crosses, such as Misome (a fairly recent hybrid between Komatsuna and Tatsoi); Da Cheong Chae (with qualities of both Tatsoi and Pak Choi); Choho (one of several hybrids of Komatsuna and Tatsoi); and Savoy Tatsoi (dark green, heavily savoyed leaves with pale green petioles, giving it a spinach-like appearance).