Here in southern Germany there are growing some walnut trees with great nuts and similar nut Shell shape, but not as such big nuts as shown, and we call them "Horsenuts".
Some nurseries are selling a great nut fruiting selection called "Finkenwerder Deichnuss Royal" (deich = dyke, nuss = nut, dyke - because selected in area of dykes at the Northern Sea)
Here are some descrdptions of this nut:
https://www.friesland-walnuss.de/unsere-walnuss-sortenhttps://www.walnuss24.de/shop/walnussbaum-sorten/walnussbaum-finkenwerder-deichnuss-royal-sFinkenwerder Deichnuss Royal
Probably the biggest and tastiest peel nut - from Finkenwerder. As a single tree or as a plantation tree for the direct marketing of nuts. It is a protected variety.
This nut was bred on the Elbe island Finkenwerder in Hamburg. With a nut size of seven centimetres, sometimes even more, it is a particularly large-fruity nut whose kernel, in contrast to other particularly large nuts, fills the shell well - a highly valued quality feature. Such nuts are much easier to dry and store than those whose kernels do not fill the shell. The variety is also rich, the fruits have a pleasant, nutty taste. If the variety were evaluated according to the criteria of the Swiss ranking list of nut varieties, it would be at the top of the list.
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Now a longer interesting article from a newspaper:
https://www.abendblatt.de/hamburg/harburg/article212123353/Die-Koenigin-der-Nuesse-waechst-in-Finkenwerder.htmlThe Deichnuss Royal has a diameter of 70 millimetres - twice as much as a fruit in a bag.
Finkenwerder. In the plantations on the Lower Elbe, the harvest is going into its final spurt. In addition to the late varieties of apples and pears, it is now also the turn of the nuts, which some fruit growers are still growing on the side. In Finkenwerder there is a special walnut variety: the "Deichnuss Royal" is not only huge but also tasty. The nut is a rarity - still.
Johannes "Hans" Pylarczik is not satisfied: The nuts on the dry sieves in front of him are good, but they are too few. "That's the same with nuts this year as with fruit," he says. "the late frost in spring caused many fruits to freeze to death on the tree."
The nuts themselves are huge. The average calibre of the Deichnuss Royal is about 70 millimetres. Some nuts even reach 85 millimetres. Pylarczik can show what this means in comparison to average walnuts on a range of calibres from Grenoble, Europe's walnut stronghold: The largest hole in the French stencil is 38 millimetres in size.
The size is not the only special feature of the "Deichnuss Royal". There are some walnut varieties with large fruit - although their diameter is usually at most 50 millimetres. Often, however, only the skin is so large and the kernel could not keep up with the growth. "This is different with our nuts," says Hans Pylarczik. "Here the kernel fills the shell completely.
Maintaining large kernels is also the real reason why Hans Pylarczik, his daughter and son-in-law bred the "Deichnuss Royal".
"We have been producing peel nuts for generations", says Pylarczik, "these are the walnuts in which the skin can be removed from the kernel with a fingernail. The skin is very bitter and without the skin the kernel tastes much milder. We then noticed that customers always prefer the largest peel nuts because it is then more convenient to peel."
So Pylarczik started to propagate only those nut trees that bore particularly large fruits. "The others are immediately processed into firewood," he says.
In order to achieve results as quickly as possible, Pylarczik does not wait for the tree to bear fruit naturally - that would be about 12 years later, but instead focuses on refinement, as in fruit growing. The grafted trees bear fruit after only two years.
Hans Pylarczik is not a pioneer for the first time: in the 1980s, he was Finkenwerder's first organic apple grower. At that time he was still smiled at. Later, when he and other organic farmers on the Elbe island took the apple variety "Finkenwerder Herbstprinz" out of the water and brought not only the apple but also Finkenwerder fruit growing back on everyone's lips, the mockery of the past had long since given way to recognition.
Pylarczik and his family no longer cultivate fruit. "You need more and more land to be profitable," he says. "For a long time, we were among those who leased land from others who had already closed down their business. In the end, we were still a handful of farms here in Finkenwerder. When I took over, there were still forty farms here. Now we have also subleased. Only the walnut trees we still have."
There are 50 walnut trees in the plantation. All carry large calibres, but only one carries the "Finkenwerder Deichnuss Royal". The application is still pending at the Plant Variety Protection Office to register the Finkenwerder Nuss as an independent variety. Biologists and bureaucrats are working on it with great meticulousness. The application was submitted in 2013. Since then, provisional plant variety protection has also been in force. If the procedure by and the "Finkenwerder Deichnuss Royal" is a protected variety, it will be propagated in a targeted manner and then be put into regular production and sale.
The variety is called "Deichnuss" because the fruit growers had traditionally planted their nut trees on the summer dikes. Due to the elevated location, they were less susceptible to frost. However, since the nature reserve "Finkenwerder Süderelbe" was established and the summer dikes are open to the public, fruit growers have been able to forget the nut harvest there. "If we want to harvest, the trees have already been plundered," says Hans Pylarczik. "The worst thing is that some people throw truncheons into the trees so that the nuts fall off. They damage the tree."
Pylarczik harvests his nuts from the ground. "Then the green skin can be loosened much more easily than when the nut is laboriously removed from the tree," he says.
The harvest is sold via the Hamburg wholesale market. Hans Pylarczik is therefore unable to say in which shops the Finkenwerder giant nuts end up. Once the plant variety protection procedure is complete, individual retailers will certainly advertise having the "Finkenwerder Deichnuss Royal" in their assortment. At the moment, you can only be sure to preserve the giant peel nuts with your own garden: Pylarczik's nursery partner Thorsten Klock sells trees grafted with Deichnuss Royal plugs on the Internet. They cost starting from 90 euro upward. That is no cheap pleasure, but a special one. After all one has then a queen in the garden
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So far to some descriptions deliverable. I have bought two plants, both for about 90 EUR each plant last year I got the first nuts, see photo enclosed which show them in comparison to another also big walnut:
I can send some seeds (nuts) in next years to anyone is interested but I do not belive that the plants will bear exactly same fruits.