Morus Kokuso

Anyone have an older specimen or know what sort of dimensions this tree will become?


Lee Reich didn’t think much of it … Mulberries, And The Winner Is . . .

He didn’t say a word about it in the article. Besides, it’s sterile and I like that premise.


He gave it three mentions, two spelled “Kokuso” and once misspelled as “Kokusu”. Internet sellers use the former.

BTW, “kokuso” is a Japanese word that translates to “complaint”. Perhaps though it is the surname of the collector as is Soybean “Kokuso”.

Mine is 4 years old and only about 12 feet tall. However about 5-6 feet of that growth was from last year. My kids loved them… I can’t even remember getting 1 last summer

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Here’s some pictures and field notes from NCGR: DMOR 13, Morus alba “Kokuso No. 20”

Richard, I’m sorry if I came across wrong to you. I read the article and he writes that he is discussing three mulberries and then writes the name Kokuso as being one of them but doesn’t give it the blue ribbon but doesn’t say anything about it, either. I was standing there staring at the stars if you know what I mean. I have seen the fruit and leaves but appreciate you trying to help.

Appreciate it, Scott. I grafted it last year on a 4’ seedling at my wood’s edge and got some real nice push from the graft. Thank you.


I had thought Kokuso was standard mulberry height? In other words, tall if you give it the chance. Mine is not so tall but it nearly got munched to death by deer. Fortunately it has finally grown beyond deer height.

No worries.

“Kokuso is another hardy and tasty mulberry although not bearing over the long season like Illinois Everbearing.” – Lee Reich

Well this Bob Harper from Connecticut sent it randomly (GW member) to me and my pal last spring so we grafted it. I did a little light reading on it at that time and since I’m in zone 5b I wasn’t even sure if it was going to be hardy. In a remote article on like page 999 of Google I read it was infertile and that really did grasp my attention. I figure I have mulberry seedlings popping up all over my woodland edges so I’d keep putting it on them and cull out the others as best I can.

I was thinking today that I had never seen how wide this thing gets and I may or may not depending on size… have one remaining place in full sun on my property for it… that’s where all this came from. I think it’s pretty evident it’s going to be a large tree… I’ll keep it at my woodland edge and also where I stuck more grafts of it again, this year.

Thank you very much, gentlemen.


I always assumed Kokuso No. 20 From USDA was the Kokuso sold by a few nurseries. Does anyone know this for certain? The number made me think they were likely several selections. I found it fairly easy to root compared to some. My original tree doesn’t seem to be growing to large and is low branching. To this point I certainly have not had to prune agressively like some of my others.

Check with the donor listed on the DMOR 13 page.

How do you get deer to eat mulberry trees? What a benefit!! That is important info for some one who thinks mulberry is a noxious weed.

Based on my deer observations its their favorite tree leaf.

I just grafted some varieties to my Kokuso yesterday and made sure to put them high enough beyond deer range.

Curious if anyone has further experience (of the eating type) with this variety?

I’ve eaten several of these and I’d say it’s good; not phenomenal. IL Everbearing is much more complex in flavor and I’d rate IE as great instead of good.



I wish I had better record of some of the more obscure things I’ve drummed up and read, but doing some research last year (or so) I found a summmary (or something like that) of breeding trials/evaluation of the Kokuso selections. I’ll hunt for it, as it’s best to cite these things, but per memory, there were some interesting revelations. 1. the breeding work was done in Japan, not Korea, as is universally claimed 2. The breeding project was entirely geared toward fodder for silk worm production. They made no effort to evaluate (or even make note of) fruit production. As I recall, the breeding was done quite a while ago. I want to say 1940’s or so.

Looking at the leaves, which are fairly enormous, it’s not surprising that it was grown and selected with that in mind. Funny, reading back on this (old) thread to see some mention deer browse, etc. In the agroforestry world it’s considered one of the premier woody fodder crops, and is said to be extremely nutritious and to contain a near perfect balance of carb and protein. I’ve seen squirrels and chipmunks eat the buds en masse one by one. Even people eat it! The young leaves are used as a vegetable in some places. ‘Perennial Vegetables’ author Eric Toensmeier was evaluating several varieties for flavor and palatability some years back.

That was easier to find than I thought it’d be:

Quoting the some of the pertinent parts I referenced: