Asian Greens for March: Yukina Savoy in the Hoophouse

Koji Yukina Savoy in late December.
Photo Pam Dawling

I wrote about outdoor Yukina Savoy going into the winter, in my October post. Re-read that to get details of days to maturity, cold-tolerance (10F/-12C outdoors) and the differences between the open-pollinated Yukina Savoy and hybrids such as Koji. Five months after that posting we are harvesting the last of the over-wintered Yukina Savoy in the hoophouse. For us, this is a cooking green, not a salad crop. It’s delicious and easy to cook. A little robust for salads, for most people.

Young Yukina Savoy plants in our hooophouse.
Photo Wren Vile

In March we are starting our hoophouse crop transition to early summer crops (tomatoes, peppers, squash, cucumbers) and meanwhile we are enjoying harvests of arugula, brassica salad mix, Bulls Blood beet greens, chard for salad and cooking greens, Russian kales, leaf lettuce, lettuce heads, baby lettuce mix, mizuna and frilly mustards, radishes, scallions, senposai, spinach, tatsoi, turnips and greens and yukina savoy.

We do two hoophouse plantings of Yukina Savoy: the first transplanted from outdoors on October 6, feeds us from December 5 to January 31. The second, transplanted from outdoors on October 24, feeds us from January 8 to early March, sometimes to mid-March. This spring several crops are bolting earlier than hoped-for! We have had some back-and-forth temperatures, which can trigger bolting. Among brassicas, Yukina Savoy is relatively heat-tolerant. This is part of why we do the second planting – it helps us extend the brassica season until we can harvest more outdoor kale.

We transplant Yukina Savoy at 12″ (30 cm) apart in the row, with 4 rows to a 4′ (1.2 m) bed. For a hundred people with lots of other vegetables available, we plant 60 in the first planting and 40 in the second. There are too many other crops competing for space in late October for us to plant more than 40.

Harvesting Yukina Savoy leaves in late November.
Photo Wren Vile.

Initially we harvest this crop by the leaf, until we see the stems start to elongate prior to bolting, when we cut the whole plant. (It is a loose head type of crop, so don’t wait for a firm head to form!)  Actually we pull first, then cut off the head, then bang two roots together to shed the soil, and put the pulled root stumps on the bed to dry out and die. This is easier than cutting first and pulling later. If they do bolt before we get round to pulling them, I have added the pretty yellow flowers to the salad mix. Like all other brassica flowers, these are edible.

Kitazawa Seeds tells us that Yukina Savoy is a Brassica rapa Pekinensis group, for those with a love of brassica botany and those saving seeds. Also those, like us, looking for nematode-resistant vegetables. Brassica juncea are the most resistant brassicas. Kitazawa classifies it as a loose head type of Chinese cabbage.

Yukina Savoy in the early morning mist.
Photo Wren Vile

Asian Green for February: Tatsoi

A large tatsoi plant in our hoophouse in December. Photo Kathleen Slattery

Tatsoi is a very cold-hardy green (down to 10°F, –12°C), one of the ones we grow in our hoophouse to feed us after the winter solstice, when the crops have started to be fewer in number and each is less abundant in production rate.  We have also grown this one outdoors in the fall for early winter eating, but no longer do this as the rate of growth inside the hoophouse is much better. In the fall tatsoi will not bolt, but in late winter/early spring it will.

I have been writing about a particular Asian green once a month since last May. To find the other articles, click the category “Asian Greens”.

Like Asian greens in general, tatsoi is a great crop for filling out winter CSA bags or market booths, and ultimately, dinner tables. Because the Asian greens are so varied in color, texture, shape and spiciness, you can add a lot of diversity to your crops by growing a selection that is easy to grow and can all be treated the same way. They are as easy to grow as kale. They germinate at a wide range of temperatures and make fast growth (much faster than lettuce in cold weather!)

Botanically, tatsoi is Brassica rapa var. narinosa, cousin of other turnip family greens such as Chinese cabbage, Tokyo Bekana, pak choy, mizuna and komatsuna. It is a more distant cousin of the Brassica oleracea greens such as Vates kale, Chinese kale and kai-lan, and of crops in the Chinese Mustard family, Brassica juncea (the frilly mustards like Ruby Streaks and Golden Frills).

Tatsoi is a relatively small plant with shiny, dark green spoon-shaped leaves and green-white stems. If given plenty of space it grows as a flat rosette, but if crowded it takes on a flowerpot shape. For sale, the whole plants are cut and the leaves banded together, so crowding them does not at all make them less marketable. It has a pleasant mild flavor.

Young tatsoi plants in our hoophouse.
Photo Bridget Aleshire

Growing Tatsoi

We direct sow and then thin into salad mixes, leaving some to mature at 10″ (25 cm) across for cooking greens.  You can also transplant at 3-4 weeks of age in the fall, at 6″ (15 cm) apart. Although we transplant most of our brassicas, to allow the beds more time without this crop family (which we grow lots of), we direct sow this one, which will have many plants in a small space.

Tatsoi has similar care requirements to other brassicas. Very fertile soils grow the best Asian greens, so turn in leguminous cover crops or compost to provide adequate nutrition. Asian greens are shallow rooted – Pay extra attention to providing enough water to prevent bitter flavors and excess pungency. Expect to provide 1” (2.5 cm) of water per week in cooler weather, 2” (5 cm) during very hot weather.

Do close monitoring for pests, which can build up large populations during late summer. We do nothing special for our tatsoi, but if you have a lot of brassica flea beetles or uncontrolled caterpillars, cover the sowings or new transplants with insect netting such as ProtekNet.

If you are growing tatsoi outdoors in late fall, you could use rowcover to keep your plants alive longer into the winter.

For our hoophouse, we make a first sowing of tatsoi in the very first bed we prepare for winter crops, on 9/6. We make a second sowing in mid-November. The first sowing will feed us for two months, November and December.  The second sowing will feed us for a much shorter period of time: the second half of February, first week of March. It would bolt if we tried to keep it any longer.

It is entirely possible to make sowings between 9/6 and 11/15, and get harvests that last longer than our 11/15 sowing. The only reason we don’t is that we have so many other crops we love.

Kitazawa Seeds have a Red Violet tatsoi/pak choy hybrid, with an upright habit. They classify tatsoi as a type of pak choy/bok choy/pak choi, so if you are perusing their interesting site, this is how to find tatsoi.

Tatsoi ready for harvesting of whole plants.
Photo Pam Dawling

Harvesting Tatsoi

Tatsoi takes 21 days to be big enough for baby salads; 45 days for cooking size.

To harvest, initially we thin the rows to 1″ (2.5 cm), using baby plants in salad mix. Our first sowing provides thinnings from 10/8, one month after sowing. Next we thin to 3″ (7.5 cm), using these also for salad. Our next thinning, to 6″ (15 cm) gives us small plants for cooking. After this, we harvest individual leaves for salad or cooking. The second sowing provides thinnings 12/27-1/21 approximately.

Once we get close to the time the plants would bolt, we pull up whole plants and use them for cooking. We pull the most crowded plants first, giving the others time to grow bigger – they can grow as big as 12″ (30 cm) across. Overcrowding can lead to early bolting.

Overview of Winter Hoophouse Greens

In the big scheme of things, we harvest Tokyo Bekana and Maruba Santoh for heads in December, along with our first tatsoi; our first Yukina Savoy, our Chinese cabbage and Pak Choy in January, our second tatsoi and Yukina Savoy in February and early March.

Non-heading leafy greens such as Senposai, spinach and chard feed us all winter until mid-March when we need the hoophouse space for spring crops. (Read more about Yukina Savoy here in March.)

After Tatsoi

We clear our first tatsoi by 1/14, and use the space to sow our fifth spinach on 1/15. This planting of spinach is to be used as bare root transplants outdoors in March. Our second tatsoi is cleared 3/12 to prepare the space for early summer crops like tomatoes, peppers, beans, squash and cucumbers.

Beauty in a tatsoi plant.
Photo Wren Vile

Hoophouse winter greens, transplanting spinach, crocus flowering

Russian kale, yukina Savoy and lettuce from our winter hoophouse .
Photo Wren Vile

Our hoophouse is bursting with winter greens. We just decided to hold back on harvesting our outdoor Vates kale and focus on the greens  which are starting to bolt in the hoophouse. That includes the last turnips (Hakurei, Red Round and White Egg), Senposai, tatsoi, Yukina Savoy, mizuna, Ruby Streaks, Scarlet Frill and Golden Frills mustards. Big but happily not yet bolting are the spinach, Rainbow chard and Russian kales. A row of snap peas has emerged. Time to stake and string-weave them!

The lettuce situation is changing as we are eating up more of the overwintered leaf lettuce in the hoophouse. The lettuces in the greenhouse have all gone, to make way for the flats of seedlings. Plus, we needed the compost they were growing in, to fill the flats. More about lettuce in February next week.

We have also cleared the overwintered spinach in one of our coldframes, so we can deal with the voles and get them to relocate before we put flats of vulnerable seedlings out there. The voles eat the spinach plants from below, starting with the roots. We had one terrible spring when they moved on to eat the baby seedlings when we put those out there. After trial and error a couple of years ago, we now clear all the spinach from one frame, then line the cold frame with landscape fabric (going up the walls a way too), wait two weeks, then put the seedlings out on top of the landscape fabric. The voles by then have decided nothing tasty is going to appear there, so they move on.

Spinach over-wintered in our cold frame
Photo Wren Vile

Outdoors, we have just started transplanting new spinach. We have four beds to plant, a total of  3600 plants, so we have to keep moving on that! We are trialing several varieties again, as we did in the fall. We have the last Tyee, alongside Reflect and Avon this spring. Inevitably things are not going perfectly according to plan. Yesterday I forgot to follow the plan, and we started with Avon and Tyee at opposite ends of a bed we had planned to grow Reflect in! Anyway, we are labeling everything and hoping to learn which have best bolt resistance. Watch this space.

We have grown our spinach transplants (as well as kale and collards) in the soil in our hoophouse, sowing them in late January. I wrote about bare root transplants in early January this year. You can find more links and info in that post. Growing bare root transplants saves a lot of work and a lot of greenhouse space.

For those relatively new to this blog but living in a similar climate zone, I want to point you to The Complete Twin Oaks Garden Task List Month-by-Month. It includes a link for each month’s task list. I notice from the site stats that some of you are finding your way there, but now there are so many years’ worth of posts it’s perhaps harder to find. Happy browsing!

Following on from last week’s mention of harbinger weeds of spring: chickweed, hen-bit and dead-nettle, I can now report that I’ve seen a flowering crocus (2/17), another marker on our phenology list. The average date for first crocuses here is February 8, so they are later than usual. I did notice however, that the foot traffic over the patch of grass has been heavier than usual.

Anne Morrow Donley sent me a link to WunderBlog®, the blog from Wunderground, my favorite weather forecast station, to an article by Bob Henson: This is February? 80°F in Denver, 99° in Oklahoma, 66° in Iceland, 116° in Australia. It includes a map of the Daily Spring Index Leaf Anomaly, Figure 1.

Image credit: USA National Phenology Network via @TheresaCrimmins.

Figure 1. An index of the seasonal progress of leafy plants shows conditions 20 days or more ahead of schedule over large parts of the South and Southwest as of Sunday, February 12. Image credit: USA National Phenology Network via @TheresaCrimmins.

The post has lots of other interesting weather info too. Thanks Anne!


I remembered another of the items lost in the hacked post a few weeks ago: My Mother Earth News Organic Gardening Blogpost on Heat Tolerant Eggplant Varieties made it into their 30 Most Viewed blogposts for 2016. I’ll be writing up more about those varieties, linking the 2016 results to the weather each week (especially the temperatures) and adding what I learn in 2017.

Planting kale, catching up on weeding and reading

Vates kale Photo credit Kathryn Simmons
Vates kale
Photo credit Kathryn Simmons

Our weather has been dry and sunny (no hurricanes in September this year!) and we’ve had a chance to catch up somewhat on weeding. It’s also meant lots of irrigation, more than usual at this time of year. And consequently, running repairs. This morning I switched out three sprinkler heads – one was stuck and wouldn’t rotate; one leaked too much at the stem and one old one had ground away its brass nut over years of use and finally fell through the hole in its stand, meaning it couldn’t rotate any more either. I fixed two, still not sure how to deal with the old one. Its homemade stand is also breaking up. I’ve also been replacing hose ends and connectors – we were the lucky recipients of a donated pile of about nine hoses, some in better condition than others.

Transplanting kale has kept us busy this week. We direct sow our kale, two beds every six days in August, to make it easier to keep them well watered – we only have to hand water two on any one day to get the seeds germinated. This year we’ve had disappearing seedlings, and we’ve been moving plants around in the beds to get full rows at the right final spacing. This means even more watering, but we all love kale so much, so it’s very worthwhile. Some of the disappearing seedlings were due to cutworms, some may have been grasshoppers, and some maybe rabbits.

I’ve also been pulling up drip tape from our watermelon patch and second cucumbers, rolling it on our home-made shuttles which I described last year. I found myself salvaging 23 late watermelons, I just couldn’t resist! Watermelons in October usually get as much demand as last week’s newspaper, but while the weather is so warm (85F yesterday), people are still grateful for juicy fruit. I’m looking forward to getting more of the gardens into their winter cover crops, so that this year’s weeds can become just a memory. I also like how the garden gets smaller and smaller in the process of putting the plots into cover crops. Less to deal with. (Although I am needing to water the cover crops areas overnight with the sprinklers).

I’m in the process of writing about no-till cover crops for Growing for Market magazine. We really like using no-till winter rye/hairy vetch/Austrian winter peas before our Roma paste tomatoes. We mow the cover crop in early May, when the vetch is starting to flower, then transplant into the dying cover crop, which becomes our mulch, and also supplies all the nitrogen the tomatoes need. Anyway, that’s for the winter double issue.

Hoophouse greens in November. Credit Ethan Hirsh
Hoophouse greens in November.
Credit Ethan Hirsh

Meanwhile, the October issue has just come out, including my article about how to minimize unhealthy nitrate levels in winter greens. During winter, when there is short daylight length and low light intensity, there is a potential health risk associated with nitrate accumulation in leafy greens. Nitrates can be converted in the body into toxic nitrites, which reduce the blood’s capacity to carry oxygen. Additionally, nitrites can form carcinogenic nitrosamines. Green plants absorb nitrates from the soil during the night and in the process of photosynthesis during the day, combine them with carbon-based compounds into protein (plant material). It takes about six hours of sunlight to use up a night’s worth of nitrates. In winter when the day-length is short, the nitrate accumulated can exceed the amount that can be used during the day, and the excess nitrate builds up in the plant, mostly in the leaves, stems and roots. Leafy vegetables can then exceed an acceptable adult daily intake level of nitrate in just one small serving of greens, unless special efforts have been made to reduce the levels. My article lists which vegetables are more likely to be higher in nitrates, and which circumstances are most likely to make the levels high. I give a list of 16 steps you can take to reduce the levels of nitrate in your crops. 

There are also articles about farms getting financing from crowdfunding websites (Lynn Byczynski), customizing CSA shares using LimeSurvey to let each sharer indicate what they want by email (Eric and Joanna Reuter whose blog I have mentioned before), building a seed germination chamber (Ben Hartman), and  making cash flow projections to avert disaster (Nate Roderick). A fine batch of useful articles, and I’m especially happy to see Eric and Joanna Reuter have “joined the crew” at GFM. They impress me with their attention to details and creativity.

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