Time and Temp


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• African daisies
• California Poppy
• Calendula
• Calla Lily
• Narcissus
• Lavander
• Ivy geranium
• Mexican Sage
• Pride of Madera
• Lantana
• Society garlic
• Wild geranium


• Baby arugula
• Onion and garlic greens
• Thyme
• Rhubarb
• Parsley
• Strawberries


Harvest Tendergreen Mustard Spinach

Komatsuma only 3 weeks old!

I’ve made a wonderful discovery: Komatsuna-Tendergreen Mustard Spinach. When it comes to organizing my seed collection, I don’t have a good system. I’m much more interested in digging in the earth than setting up a proper seed file. As I got ready to plant last month, I came across envelopes with no labels or zip lock bags with a handwritten notes in them. This year I came across some seeds in a clear envelope with a scribbled note: Tendergreen Mustard Spinach. Where did I get these? Who gave them to me? When should I plant them? A little research turned up the following information.

Tendergreen Mustard Spinach, also known as Komatsuna, is a Japanese green that has been known in North America since 1930’s. It is not a true mustard, but is in the same family of plants. It has a much milder flavor than mustard and can be eaten raw or cooked. It has thick, smooth, glossy green leaves, oblong in shape.

Tendergreen mustard is widely used both in stir fry and in salads in Japan, Korea, and other Asian countries. Its tender leaves, as well as its flowering stems, are used raw or are cooked and have a flavor between mustard greens and cabbage. It can be harvested at any stage of growth.

Tendergreen Spinach Mustard is extremely hardy and is tolerant of drought and cool temperatures. It can stand temperatures in the 30’s (hear that Connecticut?) and can be sown throughout most of the year.

Thinning and harvesting in 3 weeks.

This is the part I love. Komatsuna matures completely in 40 days, but can actually be ready for the table in only 3 weeks! I planted my Komatsuna less than a month ago and I am thinning it today, using the young plants for salads. You can see that I planted the tendergreen much too close together. That’s because I didn’t know how old the seeds were and whether or not they would germinate with such poor storage. My next planting will be less dense!

There are lots of recipes on the net for Komatuna. Here’s a couple I found that sounded really simple and good:
Sauteed Komatsuna with Basil
Sweet and Spicy Stir Fry

Thank you to whoever gave these seeds to me. I’m going to try to plant them every 3 months so that I’ll have greens year around! When I save the seeds, I promise to label them properly!

15 comments to Harvest Tendergreen Mustard Spinach

  • Thank you for the message. I don’t know why there are such problems with you being able to leave comments. You could make a Yahoo email account and try using that when you leave comments. I wonder if there isn’t some box checked somewhere in your blogspot settings that is causing the problem?

    These greens sound very good. I like that the grow in low temps and mature so quickly.

  • […] wrote a post on Komatsuma mustard spinach tendergreen in March. I had found some seeds in a plastic bag in my seed box. Someone had given me the packet […]

  • […] gardener for Japanese purple mustard seeds. I’ve had great luck with the tendergreen mustard (see post) in the past, and save seeds from a few plants every year.  Japanese purple mustard is beautiful […]

  • Buzz

    Plant in full Sun to light shade. pH 6.6 – 7.8. Approximate germination time 2 – 10 days. Quick Growing! Heat and cold tolerant, leaves have a mild taste like a cross between cabbage and mustard greens. Pre-plant with plenty of compost and manure, Blood meal, Bone meal and Pot Ash, ensuring the bed contains ample nitrogen to promoting fast, healthy leaf growth (alfalfa meal, soybean meal, cottonseed meal, feather meal, blood meal, or fish meal). Prefers moisture-retentive, well-drained soil rich in organic matter. Mild flavor and can be eaten raw or cooked. Will bolt becoming bitter in hot weather. Start harvesting individual outer leaves from each plant as soon as you see many new leaves pushing out from the center of the plant. Once you have started harvesting from a plant, trim any unusable outer leaves that have become tough, weather beaten, or bug eaten, promoting rapid growth of new leaves from the center. When plants start to bolt, pull up completely, unless you want to collect the seeds for subsequent planting DANGER SEED POISONOUS!!. High in vitamins A, K, & C. Cabbage moth aka cabbage butterfly is a significant pest of this plant, covering the plant in fine netting works best. Alternaria mildew may become a problem. It helps to practice crop rotation, plant certified or treated seeds, use an anti-fungal spray such as baking soda or Neem oil, keep garden clear of host weeds such as wild legumes – yellow clover, etc. Deer resistant!

  • Joe

    Do you have any idea how/when to collect to seeds from this plant? I let a few bolt to followers and they get these pretty, yellow, small flowers, but they just fall off and I don’t see any seed pods or anything like that? Any ideas?

  • Lee

    Some of mine are blooming too. Last year I let 4-5 plants go to seed. They grew tall and produced little pods with 5-6 seeds in each one. The pods looked like arugula pods that I get. When the pods were fat with seed, I cut them off, put them in a tray in a warm, dry, place, until they dried out. Then I opened the pods and saved the seeds. I hope this cool weather will not prevent the flowers from forming pods. Good luck, Joe. Let us know how they turn out!

  • Joe

    Update: I am noticing that the stems the flowers were gowing on are starting to thicken and it looks like these will become the seed pods? If so, I am going to have hundreds of seeds from just one plant – and I let about 4 go to seed. I hope so, that will be great. I will keep you posted. Thanks!

  • lori

    are they supposed to be bitter. if not why would they be bitter?

  • Lee

    I sounds like you are disappointed that tendergreen mustard-spinach is bitter. I’m afraid it is a bit bitter. The older it gets, the more bitter it is. It can have a real “bite”. If you harvest it young (like 3-6 inches tall) it is less bitter and can be eaten raw in salads. Once they grow to maturity (12-18 inches) they taste better when sauted (like spinach). Try them different ways, you make grow to like the taste.

  • Joann

    I am amazed at how fast they grow. I got these seeds on a whim at a discount store. With my resolution being to eat healthy, what could be more healthy in mind then dark green veggies? I tossed a handful of seeds in a terracotta pot and covered it with plastic wrap. I thought I have weeks before I saw anything growing to decided where to start my garden, not the case. I live in the FL panhandle, still a slight danger of frost, can I grow these on a window sill till I have my outside garden ready?

  • Lee

    Aren’t these greens amazing! I would imagine they will grow on a windowsill but I haven’t tried it. You can also harvest them when they are small and add to a salad. Be sure you let some go to seed outside and save the seed. What I have growing now has tolerated a few light dustings of frost. Yes, I do love these greens. You can plant some seeds all year in a temperate climate but they go to seed quickly in a hot climate.

  • JB

    I too bought these seeds on discount. I was scared they would not grow so I planted a few packets close. They sprouted in days and are about 3″ tall now. I am starting to seeing the little buds for flowers on a couple of them. I think I will harvest about 2 cups at this age to toss in salad. I have never let anything go to seed and use the seeds with greens. I might give that a try this year. Thanks for the posts! Great information on these!

  • Lee

    I can find no data that says mustard seeds are poisonous as a reader has stated. Aren’t mustard seeds what we make our mustard condiment out of?

  • marcia

    Thanks for the excellent story. It was both entertaining and informative. My daughter selected Komatsuna for her Science project and she was behind schedule, so we had to select something fast growing. Your story gave us an idea about what to expect for the growth of the plants.

  • […] Spinach mustard (I had never heard of this green before, more about it here) […]

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