Friday, October 28, 2016

Harvesting Oni-gurumi in autumn of Yokohama

An entry in the Bucket List of mine is visiting the forest of walnuts in Kyrgyzstan. The walnuts’ origin is somewhere in the Central Asia. The village of Arslabob which looks like (in the map) almost the beginning of Ferghana Valley has the world’s largest wild walnuts forest. According to a guy from CBT Kyrgyzstan, they have several tourism packages to enjoy the place which takes 3-4 days by horse ride … Someday … Oh, yeah. The walnuts over there, or the nuts we find in supermarkets normally are so-called English / Persian / Californian walnuts. We can enjoy them with a nutcracker, right? A-hem, in Japan, there is another kind of walnut, juglans ailantifolia, in Japanese “Oni-gurumi 鬼ぐるみ.” Translation: Devil’s walnut. No, no, it is not something with poison. Oni-gurumi is Japanese native small walnut whose size is about 2/3 of their continental cousins. i.e. very Japanese. Though, I personally think the flavor of oni-gurumi is richer than common walnuts. They are DELICIOUS! (and expensive: my recent market research found average 900 yen per 60g of oni-gurumi). Then, why is it called Devil’s nuts? Well, try your nutcracker for them, and the tool will be broken. I mean, not a broken nutcracker in Tchaikovsky-way, but probably the whole head of the doll would be destroyed by the Devil, and the ballet will be more of a zombie movie. Oni-gurumi has an extremely hard shell. There is a trick to open the shell ;)

To crack the nut, literally, we should start from oni-gurumi’s life in the forest. In Niiharu Town, along Umeda River, I know there is at least one oni-Gurumi tree. (I don’t tell you where exactly, ha ha ha.) And near Zoorasia, along a small stream, there are two huge oni-gurumi trees that are famous among locals … Got it? Yes, in Yokohama juglans ailantifolia grow by streams. Basically, the plant grows at the edge of a mountain stream, and depends on running water for its nuts/off-springs to spread. I know a bank of moderately large river in Yokohama that have lots of juglans ailantifolia, some large with more than 20m tall, and babies of 1m or so. As I can find so many oni-gurumi trees there, I was curious what kind of forest I can find in its upstream. It soon became apparent the source of the river is now in a well-manicured city park of Tokyo. The embankment of the river is completely controlled from the start to Tokyo Bay in order to protect the sea of suburban houses both sides … Perhaps, before the World War II, the river ran rapidly within the sea of forests where many juglans ailantifolia situated themselves at the border between the land and the water. The oni-gurumi trees I can find now must be the descendants of them. By the way, there is another “gurumi (kurumi)” called in Japanese Sawa-gurumi / pterocarya rhoifolia that come out by streams in Japanese mountains just like oni-gurumi trees. This one does not produce edible nuts. If you ask about oni-gurumi to Japanese, many people would answer about Sawa-gurumi, which is confusing.

One of moderately tall oni-gurumi trees stands
just next to a large river-side condo.

As I can find so many trees of tasty nuts too near to huge towns where it seems to me not many people notice the situation, I thought I should clear the legal matters first. I emailed the City if I can harvest nuts a bit from the trees sprouting in the embankment. Their answer was as the river and its bank in question is under the jurisdiction of Kanto Development Bureau for the Ministry of Land, Infrastructure,Transport and Tourism, I should ask about it to them. OK, so I wrote an email to the Bureau for the same question. The reply I received was, as they are delegating the management of this river to the City of Yokohama, I should ask them ……. It’s so called “Typical!” situation with bureaucracy … Weeeeeeeeeeeell, as “I am a thoroughly good girl,” I made an enquiry to a policeman stationed for the police box in my neighborhood. “Hmmmmm, it would be a question falls in a grey area.” He said. “In such a case, the common sense approach should work. Unless you harvest the oni-gurumi in industrial scale, or damage the trees on the bank, I think you could have a good stand, legally …” Hmmmm. So, one early autumn morning every year, I’ve been there to have a “modest amount of walnuts” for my family.

The place where MLIT delegated the job to the City …
Harvesting ^.^
When the (possibly year’s) last typhoon has gone and
the smell of o
smanthus fragrans var. aurantiacus starts wafting,
it is time for oni-gurumi collection.
I think it is modest enough.
In any case, I left lots of nuts on the trees.
Sharing is important …

Sure, you can try to remove the outer membrane of the fruit by hand, or I should say by force. Believe me, you cannot reach to that familiar shell of walnuts in this way with oni-gurumi. Your hand-shredded mesocarp sticks to the nooks of the walnut stone no matter what. Moreover, the outer layer of oni-gurumi was once used to dye fabrics in brown so that your trial to get rid of the fleshy part of a fruit makes your hands and fingers dirty yellow. It is difficult to remove the color for days. Now, we have to recall how the tree tried to spread its seed afar. It used the stream, right? So, let’s just simply soak the fruit in a bucket of water. After 10 days or so, the fruits naturally separate its fresh from the stone. Hello, lovely walnuts. Nice to meet you! It would be the way oni-gurumi obtained during its evolution to facilitate germination. By the way, the dye from oni-gurumi membrane is with pedigree. In the Tale of Genji written in the 11th century, there is a mention where the correspondence between elegant Lady Akashi and the playboy prince Genji was done with papers “dyed by walnuts,” i.e. by oni-gurumi. For the methodology to dye fabric with oni-gurumi membrane, please check here.

Soaking the harvest.
You’d better make an insertion with knife
on the green membrane before soaking.
Like this.
I wore work gloves just for soaking,
and my fingers ended up with stains.
Two days later. The water had this color.
We can use it to dye fabric.
This site says protein-based material such as silk or wool
could respond well, but cotton or hemp does not.
The hue could be dramatically controlled by the choice of mordant.
10 days later.
Could you see the changed color of the fruit meat?
We can just twist a fruit along the knife,
and the nut comes out easily now.
My rubber gloves have been dyed already
with the walnut fruits.
The flesh of the fruit and the nuts
The water turned into this color after 10 days.
I guess we can use it to dye the fabric as well.
Or, we mash the fruit, cook the paste, strain the liquid, add mordant …
The nuts must be washed to remove the fibers
running along the seam(s) of shells.
This devil’s treat refuses to open the mouth with roasting
when the fiber remains along the seam.
Could you see the fibrous things in the water?
Oh, this brush is traditional Japanese (kamenoko-tawashi
made of the bark of hemp palms ubiquitous in the forests.

You may think you can leave the cleaned oni-gurumi stones nicely in a cute bowl, and crack them during Christmas holiday as with the standard English walnuts. Wrong approach. Once the stone is dried, they close their natural crack so tightly that without smashing the entire stone in pieces we cannot have nutmeat. The trick is, while the nuts maintained the moisture after soaking, put them in oven, and bake them at 150-160ºC for about 30 minutes. Look for the sign where steam comes out from the slightly opened seams. The oni-gurumi is ready to be cracked now. Use your minus screw driver or some tool with strong metal, to pry open the stones. Knives are risky for this operation. If they are large with strong blade, it is tricky to deal with small oni-gurumi. If they are small hand knives, the blade could be snapped easily and cause serious harms. Also, don’t wait too long for the stone to be cooled completely. The tiny opening thanks to the steam will be firmly shut when the inside air returns to the room temperature. Time is the essence for dealing with oni-gurumi …

Roasting oni-gurumi.
Could you see the steam comes out,
and the seams are slightly open?
They are now ready.
Mise en place to crack oni-gurumi
Another way to use “screw” driver
If some nuts do not have an opening,
re-roasting 5 more minute would do the job.
Caution: don’t overdo it.
The nut meat could be burned with too much roasting.
Opened walnuts
Now, we need to pick the meat out.
Like this.
Could you notice the hulls in the background
do not have any insect holes?
I have never encountered a worm-eaten oni-gurumi.
Their hulls are at least 3mm thick,
and probably insects don’t bother to reach to the meat.
This year’s harvest
They can be eaten as they are,
or used for any recipe with standard walnuts.
They look containing lots of oil, don’t they?
In order to prevent their nutritious fat to be gone bad,
I always freeze them for storage.

My experience told me this contact address is not useful for oni-gurumi … Anyway, the City Office who’s in charge of execution of Green-up Plan is

Yokohama Municipal Government Creative Environment Policy Bureau 横浜市環境創造局
Phone: 045-671-2891
FAX: 045-641-3490

Friday, October 21, 2016

Nutty fall: finding chestnuts and others in the forests of Yokohama

Ah, chestnuts … the image of Frank Sinatra and chilly early winter night in Manhattan …, or a romantic stroll along Camps Elyseés where yellow leaves of marronnier decorate the scenery … with wafting smell of roasted chestnuts … right? Whichever, I had an image of chestnuts that must come out late autumn, or early winter … Few weeks back, I posted my adventure with a hare in chestnuts orchard. That was in August, and, yeah, I noticed the trees had lots of nuts already. But their burrs were still green. I thought the bounty would be ready in October or November. I a kind of automatically felt it must have been so, otherwise Sinatra or Camps Elyseés does not make sense ...

The burrs are still very green in the middle of August …
Oh, by the way, there was a newspaper article last month
reporting Japanese hare is approaching for Red List entry.
They wrote in some prefectures including
Saitama (north of Tokyo) and Aichi (where Toyota has HDQ)
they are declared as “extinct.”
Oh my … I met a treasured resident of Niiharu …

In the morning of the last Sunday of August this year, when we cleared the dangerous branches above the trekking roads for kids, the other group of Niiharu Lovers declared they went to the chestnuts orchard to harvest. At that time, I thought it was only because Lovers come to the forest only once a week and it was a kind of measure taken under unavoidable circumstance to utilize the occasion. Then, I noticed on that same day several landlords actually went into their orchard in Niiharu and collected the nuts. I asked one of them “I thought chestnuts would be ready in October … wouldn’t they?” He looked at me with a puzzling face and said “Huh? Chestnuts must be ready in late August around here.” Sure enough, my seniors came back with a mountain of nuts. As with the bamboo shoots the bounty was shared equally among the volunteers who came on that activity day.  My family had a supper with crème de fresh marrons for dessert, in August.

The harvest from the chestnuts orchard Lovers take care of.
They are not all.
Could you see the plastic bags at the background?
Each contains a bag-full of nuts, literally.

I was honestly surprised. It was still crazy-hot, and we sweated heavily all day long. … We had fresh chestnuts in summer. Since then, I became attentive about the news for local market of chestnuts. And, YES, at least in Japanese archipelago, chestnuts are harvested by the middle of September. In order for having Sinatra-style Christmas, the nuts in Japan are not fresh but stored for at least 3 months already. I realized my notion of the chestnuts’ season has not corresponded with real lives of chestnuts in Yokohama. My brain was dominated by Sinatra and Paris … Gosh. Then, my Niiharu seniors told me, “Those chestnuts in orchards are cultivated variety. Certainly they are big, but their taste is blander than the nuts we can collect from the trees naturally grow in the forest.” “Yes, yes. The mountain chestnuts are far more delicious than the things in orchards. When we were kids, we played in the forest, and collected wild chestnuts for snacks.” ??? So, you ate the chestnuts raw? Is it possible to eat them without cooking? “Huh? Of course. Oh, here is a wild chestnut, let me see (; he skillfully peeled a tiny nut with a Swiss-army knife, and then), here, take it.” Wooooo … is it really OK without cooking? Won’t I have a stomach pain? “Of course not, try it.”

This is my another giant step for … raw chestnut.

Indeed, it was tastier than the supermarket variety. Cultivated chestnuts are … I would say, starchier. Wild chestnuts have nuttier flavor, and surely organic. This September, they took my fancy as nouveau cuisine. When I joined volunteer activities in September, I looked around and collected wild chestnuts. It was not that difficult to have another crème de marrons. It seems to me many people, who are in the end urbanites like I, do not know that tiny nuts taste better than the good-looking things in stores. To my another astonishment, the season of wild chestnuts has concluded quite quickly; at most one month only. By the end of September, they are gone. … They are precious.

This photo contains 2 giant wild chestnut trees
… I won’t tell you which. (Ha ha)
When you collect chestnuts, you don’t need scissors,
but had better wear thick-soled shoes.
They are ready when they fall off from a tree in burrs.
Often the pods open their mouth by themselves,
but sometimes they don’t.
You prise-open a husk with your shoes,
and voil
à, chestnuts!
Although their covers are equally spiky,
the mountain chestnuts are far smaller
than the artificially “inflated” chestnuts.
Wild chestnuts ^.^

These days acorn cookies are baked professionally and sold as “Jomon 縄文, aka ancient, cookies” in specialty stores. Some of my forest-volunteering buddies are trying to bake, and improve, them by themselves. In high school, we Japanese kids are taught that our ancestors of 5000 BC ate lots of nuts, including chestnuts. Now it’s a sort of trendy in Tokyo area to try such almost forgotten things of daily life. Actually, the sweets made of marronnier nuts トチの実 quietly gain popularity, as many people realize it takes professional skill to create delicate treats from marronnier. (“Oh, do you know that “patisserie” where the master can create beautiful rice cake out of marronnier?” etc.)  Unfortunately, I don’t know the place with marronnier in my neighborhood, but I know another fall bounty from forests; nuts of torreya nucifera (Japanese nutmeg yew カヤ). We can find this tree often near ancient temples and shrines as they are regulars for religious rituals in Japan. A large Japanese nutmeg yew bears lots of fruits in September, falling off to the ground. We can simply collect them to bake flavorful cookies. After roasting, I freeze them for Christmas cookies. They have dense flavor of nutty oils that can match well with strongly bitter chocolate. If you find a yew tree in Yokohama’s forests, try them!

Japanese nutmeg yew
at the entrance of Asahina Kiridoshi 
It has “shimenawa
注連縄” like sumo wrestlers,which
means people has found something sacred with this tree.
Fruits of Japanese nutmeg yew.
Their size is about 2cm long.
Inside of green meat, there is a nut.
They look like almonds.
Washed nuts.
The raw nuts of torreya nucifera taste bitter.
Some say if we harvest in late autumn
by digging them out from the soil,
the harshness can be gone.
I’m not sure about the sanitary aspects of this methodology
so that I always pick yew nuts of September
and soak them overnight with bicarbonate solution before roasting them.
The amount of baking soda is, er, “as you like it.”
I think too much of soda could overkill the nutty taste.
Here, I put, … 1 tbsp? for approx. 1.5L of water.
After soaking, roast them with 160°C for 12 minutes or so.
It’s like roasting walnuts,
but the husk of yew’s nuts are thinner
so that we have to adjust the time accordingly.
Roasted yew nuts.
We can know they’re done when some of them had cracks.
As you could see, the husks of yew nuts
(on the right of the photo) are thin, but hard.
After roasting, I always crack the nuts before they become cold,
and freeze them for winter.
Yew nuts contain lots of fat,
which means leaving them after roasting in room temperature
could ruin their flavor.
It would be wiser to prepare them promptly.

If you find a problem in the Niiharu Forest, please make a contact with

Office for the Park Greeneries in the North 北部公園緑地事務所
Yokohama Municipal Government Creative Environment Policy Bureau 横浜市環境創造局
Phone: 045-311-2016 (I guess in Japanese only)
FAX: 045-316-8420 (I hope there is somebody who can read English …)

Niiharu Administrative Office / Satoyama Exchange Center 新治管理事務所・里山交流センター
Phone: 045-931-4947
Fax: 045-937-0898

Oh, yes, Lovers of Niiharu has changed the homepage address. The administrator told me they are welcome for comments etc.

Friday, October 14, 2016

Attack of the Clones? Bamboos, bamboos …

When I was a simple hiker visiting city forests occasionally, I thought Niiharu is probably one of the best maintained forests in Yokohama. Now I realized there still are lots of things to be improved. Take bamboo shoots harvesting. For more than a month this year, weekly volunteering by about 60 people yielded hundreds of shoots that could be sold at a good price if marketed. But when the shoots had become commercial products, the elderly landlords must have thought about management issues and taxes which are too much for them. That was the original reason why such a rich bamboo forest is a part of Citizen Forest, and volunteers are inundated the weekly supply of shoots. There must be some policy solution for the situation … Taking care of bamboo forest requires all-year-round labor intensive tasks. Some trees become prematurely yellow any time. The others are broken due to storms. The broken bamboos can be a danger for visitors who must pass under the precariously hanging broken limbs. They must be taken away ASAP, if the forest receives lots of weekend hikers. Even if the location is not open for the public, abandoned bamboos could pose another problem. Bamboos are very elastic. When they collapse and wither, their bottoms are still attached to the rhizome underground. The tethered “net” of broken bamboos obstructs the new growth of shoots from the jumble-covered ground, let alone sunshine for the other vegetation to sprout. Furthermore, a network or bamboo rhizome occupies only top soils. The bamboo “mesh” is not strong enough for the impact of rapid torrential rain, or large earthquakes, especially where the rhizomes completely dominates the ground and the soil in-between is washed away. A neglected bamboo forest becomes a good candidate for the next large landslide. Meanwhile, for example, in Niiharu Forest all the bamboo fields are private properties of several landlords. Majority of them are households of senior citizens. I realized how labor intensive digging bamboo shoots is. Maintaining the soil of bamboo field is not a lonely job for an abuelita of 75+ years old. We return to the land management issue in aging society … the spread of neglected bamboo forests is becoming serious ecological problems.

The problem may not be so pressing when the plant takes their time to grow as the other trees do. Bamboo spreads ferociously similar to herbaceous. The secret why bamboos can grow so fast is in the sections of its trunk. They are apical cells of bamboo. When a bamboo gets taller, all the cells in the sections grow at once. A healthy bamboo can have 60 sections with lots of apical cells, and hence the tree can become 20m high in less than 2 months. Their rhizome also has a similar structure and can grow 7-8m long underground. In addition, it is ever-green, which makes them possible to photosynthesize and grow during the winter. A vigorous bamboo forest in Satoyama consists of only one sequence of DNA explosively started by one bamboo shoot transplanted from somewhere. They are clones. Once established, without a proper control in humid Japan, they can cover a wide forest floor with the shadow of canopy, thick fallen leaves below, and a network of its rhizome beneath, all of which impede growth of the other plants. In addition to disaster risk reduction, controlling a bamboo forest is important to protect the other forests from the attack of the clones.

er … those clones are cute.

In Japan, the bamboos we can find easily are either pubescens with 1 ringed section, or bambsoides with 2 sections. Legends say phyllostachys pubescens was imported from China in 801 or 1228 by Buddhist monks who studied in China. It is almost sure that pubescens became “vegetable” when in 1736 the lord of Kagoshima ordered his subordinate to bring its seedling from Okinawa where already the Okinawan dynasty had introduced them to eat from the continental Qing dynasty. In standard “farming” of bamboo shoots, we cut the phyllostachys pubescens when it reaches 5 years or so old in order to stimulate more new shoots in spring. Moreover, before plastics the large trunks of pubescens provided lots of materials for the tools in daily lives, such as bucket, kitchen gadgets, utensil, and dishes all of which required almost annual replacement. Cutting them frequently was natural for bamboo farmers. On the other hand, some think phyllostachys bambsoides is Japanese native bamboo. The garden structures we can find in traditional Japanese gardens are often made of bambsoides. Bambsoides are thinner than pubescens. Their shoots are also edible; there are lots of gourmands who prefer bambsoides to pubescens. Unlike pubescens, the shoots are harvested when they are 30-40cm tall above the ground and still so soft that they can be broken from the root by hands. Immediately after the harvesting, the shoots of bambsoides do not require preparations for cooking as pubescens. Do you remember we encountered a BBQ party in Jike Citizen Forest last year? The landlords entertained the visitors with freshly harvested shoots of bambsoides by roasting them over charcoal fire, just like sweet corns. The slender bambsoides can provide smaller amount of materials for crafts. In addition, bambsoides are not that much vigorous for shoots as pubescens. There wasn’t strong demand to cut bambsoides as for pubescens. The traditional way of dealing with bambsoides is leaving the trees to be old enough for creating a gnarled trunk or odd shapes, in order to be appreciated as a material of Japanese traditional art. Especially when it sprouts from a steep slope and shot up in a curved way, the form of the trunk becomes ideal for shakuhachi flute. Older arched bambsoides with a large cavity surrounded by thick old trunk wall can fetch a fortune to be a “Stradivarius” of shakuhachi. Unfortunately, the long-terminalism for maintaining bambsoides forest has a hidden danger: they are easy to be neglected, especially in Japan these days with lots of senior citizen landlords.

It’s a bambsoides forest in Ikego.
The reason of neglect here would not be aging society,
but … international politics?

Niiharu is situated almost in the center of Tama Hills. This part of Japan has been famous since the 18th century for bamboo shoots cultivation, catering megalopolis of Tokyo. So, Niiharu Forest has lots of bamboos. Compared with the other places in Yokohama, Niiharu’s bamboo forests are really kept well in general, especially where we can harvest the large bamboo shoots, i.e., the forest of phyllostachys pubescens. Even though, Niiharu has problem spots of one or two. A forest of phyllostachys bambsoides was the one.  They were damaged by heavy snow 2 years ago when lots of trees were broken and fell. The landlord does not have resource to tackle the problem. Uber busy Niiharu Lovers finally found time to attend the issue this spring.  A Niiharu’s bambsoides forest is small and surrounded by the pubescens. My seniors assessed the field and concluded that there is a strong possibility that the weakened bambsoides will be invaded and dominated by pubescens eventually … “Any way, let us see if we can restore the bambsoides forest by first clearing the broken and dead trees.”

A bambsoides forest in disarray

A disaster such as unusually heavy snow can first bend the bamboos. If it occurs in a neglected bamboo forest, too much density makes a mesh of bended and broken tops of bamboos whose weight eventually causes the whole a net to fall down to cover a wide space. It was a mess. To sort out the situation, we had to wade in the heap of entangled, pointed, and dry branches of bambsoides. We then cut the end of dead tree, undid the complication and made bamboo logs for disposal. The bamboos logs dried in this way were too damaged to be material of crafts or gardening, other than being crushed for mulch. That’s really wasteful …

Could you see the top of the bamboos were entangled
and drugged the entire trees to the ground?
Let’s tackle the fundamental problem over there.
As long as it stood upright,
yellowish leaved trees were left for the forest restoration.
My seniors decided to stop clearing here,
and to wait and see how the forest cures itself.
They said the place would be a good playing ground
for corvus macrorhynchos meanwhile.
Logs of dead bamboos.
We have to carry them out from the site later
in order to prevent arson, and other nuisance.

Even though, I noticed Niiharu’s phyllostachys bambsoides fairs better. One of the requirements for Forest Instructor Course by Kanagawa Prefecture is accumulating the experience in the forests of entire prefecture. One weekend, I joined an event to take care of a forest owned by the City of Kamakura. Due to a heavy rain, the planned forestry exercise was changed into a stroll in the forest that is not officially open. We walked in a forest hill which was once the property of Nomura Research InstituteIn 1989, they moved out the place and donated the entire land to the City of Kamakura … The buildings Nomura used are still standing although the concrete of the outer wall is crumbling. “Please do not go near to the structure. They are dangerous.” The people from the Prefectural government warned us. The hill is covered completely with overgrowth from the top to the ground. The donated hill looked abandoned as a whole. The messy forest with which we could have done the job was of a phyllostachys bambsoides … The bamboo trees stand too close each other which makes lean phyllostachys bambsoides even leaner than in a healthy forest … That was a sad scene. … Hmmmmm, the place surely needs lots of helping hands, as the lecturers for the Forest Instructor Course told us …

A former office building of NRI.
It could be another site for 007 adventure someday …
The entire hill is covered with overgrown everything
… asphalted roads are also crumbling, actually.
Although they are too short,
the bamboos are already getting yellow.
It is definitely impossible to walk
in this forest with an opened umbrella.
(Oh, yes, the metric for thinning bamboos is
“making space between the trees
that is wide enough for a person
with opened umbrella to walk.”)
That pointed cutting of a bamboo in the middle is
a prohibited way of thinning the forest …
probably somebody cut the bamboo just for fun …

If you find a problem in the Niiharu Forest, please make a contact with

Office for the Park Greeneries in the North 北部公園緑地事務所
Yokohama Municipal Government Creative Environment Policy Bureau 横浜市環境創造局
Phone: 045-311-2016 (I guess in Japanese only)
FAX: 045-316-8420 (I hope there is somebody who can read English …)

Niiharu Administrative Office / Satoyama Exchange Center 新治管理事務所・里山交流センター
Phone: 045-931-4947
Fax: 045-937-0898

The contact address for Kanagawa Green Trust かながわトラストみどり財団 is

Phone: 045-412-2255