Nötodling in Sweden – From 3: Walnuts

Walnut Tree (Juglans spp.) includes a number of species that are interesting for our Swedish conditions. Genuine walnut (Juglans regia), which is also the most famous walnut usually do to the cultivation zone 2 in Sweden. The genuine walnut big advantage is that they are tasty nuts are easy to crack and the nuclei remain intact and are easy to get out of the shell.

year garden book 2018!

Its limited hardiness however, has been a major limitation so far, but since the fall 2013 propagates the promising Belarusian variety ‘Loiko 63’ in Lars Westergaard's nursery outside Odense in Denmark. OLoiko 63´ originates from a trial cultivation in Belarus and 2003 planted 100 seedlings in Sweden. The seedlings were taken to Sweden by plant enthusiast Ove Johansson living in Indal outside Sundsvall and the seedlings were distributed across the country. Ove's son Louis has also written a very interesting book called " Grow exotic in your garden” (2007) where he coined the term "extreme growers' I can somehow identify with.

Martin Gustafsson shows up the real walnut Loiko at Uppsala Botanical Garden.
Martin Gustafsson shows off the real walnut ‘Loiko 63’ at Uppsala Botanical Garden.

The seedlings from Belarus show excellent hardiness and gave a harvest in the Sundsvall region already in the autumn 2008. To our great joy comes a clone ‘Loiko 63’ to come to Stjärnsund in the spring and enrich our collection of nut trees. Genuine walnut gives fruit after about five years. Young trees can produce 2 to 5 kg of nuts per year, while the trees 10 to 20 year-old gives between 15 and 50 kg of nuts per year, and 1,6 to 5 tonnes per hectare per year [1].

There are an incredible number of cultivars of genuine walnut, but it is unfortunately not so many of them that thrive in Sweden.
There are an incredible number of cultivars of genuine walnut, but it is unfortunately not so many of them that thrive in Sweden.

In addition to the Loiko nuts, Manchurian walnut is considered (Juglans mandshurica) be the hardiest species in the genus. It thrives well in cultivation zone 5 and there's even copies of Jämtland, but the nuts are very brews, with small grains that break easily when the nut is cracked. In the colder parts of Sweden, it may be an option for lack of other species, or until varieties of the same quality as the Loiko nuts have become more widespread.

Black walnut (Juglans cinerea) cultivated as park trees in many Swedish cities and the species is considered to be resistant to cultivation zone 4 or 5. The nuts are very creamy and tasty (the English name is Butternut), but brews and even these nuclei break easily when it breaks. There are cultivars from North America that exhibit better properties, so that Booth, Beckwith and Bear Creek available on the European market. Butternut gives fruit after 5-8 years after they were planted and the relatively short-lived trees (80-90 years) gives 14-23 kg of nuts per year.

All walnuts sits nuts in bunches on this picture.
On all walnuts, the nuts are in clusters, but the number of nuts in each group varies widely between different species and between different individuals within the same species. It can be anything from 1-25 nuts in the same bunch. Here is a Japanese walnut (J. ailanthifolia) who often form classes with many nuts in it.

Heartnote (Juglans ailanthifolia var. cordiformis) is a subspecies of the Japanese walnut (Juglans ailanthifolia) with heart-shaped, very tasty nuts of many nötkännare considered the most delicious walnut. The species is possibly resistant to cultivation zone 4 and the variety 'Kalmar' has shown very good properties in Danish experimental garden [2]. I have just got hold of a seedling from a tree in Singapore and have had the variety 'Feed Maier' for two years, who has done really well in the forest garden. Name Places of Heart notes begin to produce nuts for five years after planting and then produce on average 2,3 kg of nuts per tree. After 10 years, they produce 23 kg per tree, and when they are older than 15 years after being its maximum production on average 34 kg of nuts per tree.

Heartnote (Juglans ailanthfolia var. cordiformis) is both beautiful and good.
Heartnote (Juglans ailanthfolia var. cordiformis) is both beautiful and good.

Buartnut (Juglans x bisbyi) is a hybrid between Butternut and Heart notes, which is believed to reconcile the gray walnut hardiness with hjärtnötens culinary properties. We planted two copies of this hybrid a few years ago, but unfortunately they suffered any DECAY DAMAGE and withered down shortly after planting out. So far we have not been able to get hold of new seedlings.

Black walnut (Juglans nigra) descended like Butternut from North America and has been cultivated there for a very long time. It has a delicious flavor and some cultivars released the kernel freely and in one piece, Thus, without falling apart into a thousand pieces, but it is also by far the most brews walnut. The shell is so hard that it was used as a heat shield in the first American space shuttle, and even today used the crushed shell as abrasives in industrial contexts. Seedlings of black walnut gives fruit only after 12-15 years and then produce around 8 kg of nuts per year. Mature trees can after about 50 year give 100 kg of nuts per year. Grafted trees can produce fruit after a few years [1].

Black walnut Thomas
Black walnut (Juglans nigra) has incredible brews nuts, but they are very good.

All walnuts need a warm, well-drained habitat, while they must be able to access ground water with their long pålrötter that can be three to five feet deep with full-grown trees [3]. Therefore, it is perhaps not surprising that in their natural environment often occur on slopes near rivers. In the first years investing walnuts most on developing pålrötterna and they are therefore very sensitive to transplanting. They do not like to grow on soils with low pH and thrives best in soils with pH 6,5 or higher.

Heart-nut trees are fast growing and become very large. This tree grows in Martin Crawford nötlund and is only 16 years old.
Heart-nut trees are fast growing and become very large. This tree grows in Martin Crawford nötlund and is only 16 years old.

Walnut leaves contain a herbicide called juglone that inhibits the growth of other plants. Juglonets effect is relatively limited regional, but apple trees show great sensitivity to the poison and should be planted away from walnut trees. A selection of plants that can tolerate juglone and which therefore lends itself to co-planning with walnuts shown in the table below. A more detailed summary that distinguishes between three different time and that also includes annual crops and animals are in a scientific article from 2008.

Juglonresistenta plants (from [4]).

Swedish nameBotanical name
MapleAcer spp
AlliaceaeAllium spp.
VårskönaClaytonia sibirica
HagtornCrataegus spp.
Jerusalem artichokeHelianthus tuberosus
Day LilyHemerocallis fulva
Spanish chervilMyrrhis odorata
JätteramsPolygonatum biflorum was. Commutator
IQuercus spp.
ElderberrySambucus spp.
MaskrosTaraxacum officinale
White cloverCLOVER

Walnuts are usually wind-pollinated and requires a different kind (or species) to give fruit. Some individuals are self-pollinating or develop the ability to pollinate themselves when there are no other walnut trees near. Other individuals can put fruit without pollination has occurred, a phenomenon called apomixis [2].

Both hazelnuts and walnuts are among the fat-rich nuts and in the next post we will look at the chestnuts, belonging to the starchy nuts.

Literature

[1] Crawford, M., Nut Crops – Appendices, 2012.
[2] Westergaard, L., 2013 [personal communication].
[3] Mohn, C.P.F.H.G.E., The modern silviculture of Juglans regia L.: A literature review. The Natural Resources., 60(3): p. 21-34, 2009.
[4] Jacket, D. and E. Toensmeier, Edible forest gardens. White River Junction, Vt.: Chelsea Green Pub. Co., 2005.

61 thoughts on “Nötodling in Sweden – From 3: Walnuts”

  • It is so fun that it happens a bit in this area. When I was young I read that walnuts are not formed on the trees in Stockholm,, it was cold uždraustas… Not konspektas so that vyras got geismas to try da.. Maybe they needed pollinated PR Annanas Rūšiuoti, vyrai it was not mentioned as a possibility.. I have at patenka Fatt nuts on the kind BROADVIEW in Zone III in Upland.. With the enthusiastic pioneers vyras can probably find suitable rūšiavimo uždraustas Cellar Act SA..

  • Is there any walnuts or only the black producing juglone? Just find info on the black incl article you link to.

    • Hi! All walnuts produce juglone! Whether the amount they produce differ between species I know unfortunately none of.

  • Great with walnuts. Have you read Dan Carlsson – Soonic Bloom with audio and nutrient spray on black walnut and later in the walnuts when the next year would sprout – managed to get much higher yields, faster growth + they tolerate cold better. Such walnuts can certainly purchase seed.

    Do you know that the pine nuts can be grown throughout Sweden and that the spread of Nutcrackers. It is called the Siberian cedar or stone pine and planted outside Luleå in the 1800s when it was called the bread pine. The outer part of the twigs can make green smoothies with a little fruit, which is a little better than pine sprigs (but the taste may not be discussed?). Plant lots. Buy cheap plants from Russia that we can share if someone has way past where they are?

  • Tack, it was very enlightening. A couple of issues. How far is “Keep away” for example, apple trees and bushes? Where can I find walnut seedlings (real walnut) to buy?

    • Hi! I would guess that it is enough if the apple tree / bärbusken standing outside valnötens prospective crown, Thus about. 10 m from the tree. Honestly, I have not yet been able to observe juglonets adverse effects in the reality of solitary trees of walnut, so I think it's a bit exaggerated.
      Suitable walnut seedlings Zone 1 and 2 you can buy among others. Westergaard in Lars and Agrofroestry Research Trust (is http://skogsträdgården.stjärnsund.nu/plantskolor-for-skogstradgardsvaxter/).
      Please
      Philipp

      • Intill, 1-3 m från stammen och klart inom kronans räckvidd, vårt valnötsträd (ca 30 years)finns idegran, redcurrants, plums, små klarbär och någon inträngd buskros. Lite längre ut, men fortfarande inom kronans radie finns äppleträd och diverse perenner. Lite trångt blir det så alla växter har väl inte optimala förhållanden, men det känns inte som om det handlar om juglonpåverkan.

  • Hi! I have a giant walnut trees, guessing 8-10 m on my little plot in Southwest Skåne. now by 7 years, growing amounts of walnuts on the tree. How will I take care of them?
    They seem to fall down on the ground and then I think the birds take them. has managed to save 10-12 pc previous years. Shall I put sheets on the ground? When should I take them? They must be colored before I can pick them. Thinking maybe a ladder and pick them down, but when?

    • When they fall down, they are mature. Sheets seems unnecessary. When they become mature and fall can shake them down. You can also pick them with green shell remains, but then you have to let them be o mature finished indoor one week until the skin blackens and falls away (extremely meckigt to remove the shell without detbörjat blacken – Moreover, you should use gloves for the black remains for several days, how hard you scrub your hands (man made of ink in the old days))

  • Have a walnut tree planted in -70 the number , which in recent years has given me a lot of nuts, but, it is a constant battle between me and the raw cows. They struggle with their beaks and take many nuts, They take the top that I still do not reach is ok, but I want to have as many as possible. I wait until the nuts yourself fall down, I learn not to get so many. Is there a trick to easily get the nuts ( from the fruity shell), whose economies have not yet opened up? Should they be dry or damp?

    • I have put the nuts in a plastic bag which I made tight. After a week or so the shell starts to rot and then it's very easy to get it off. The nuts tasted good anyway and did not seem to have been damaged by this treatment and can be dried without the problems. Hope that helps!

    • I have a trick. 4 meters long string that is somewhat resistant. Binds an apple in one end. Then I throw it over the branch I want to access and prisoners, and suddenly I have the best hook the branches I can not reach

      • And, Speaking of Philipp mentioned, I put them in their green shells in a sunny window for a few days. When they become skrynkligaär easy turning of the green shell.

        • Thanks for all the tips!
          Having now spent the weekend at the walnut harvest catch up with raw cows.
          They help the some! the judgment is losing the pre-peeled in the väggitationen.
          Then sacrificed an old paring knife ( the handle is the color) to those who have not yet opened up; but saw “actual ” out. Did a notch ,around in the thick green husk,where the natural crack usually come (as you do when you peel an orange, some needed another notch, so the shell was divided into 4 parts) then it was too easy to get the shell.
          Good luck to all the walnut growers

      • I have the best picker tool to walnuts, a golfhåv that golfers have to pick balls when the balls end up in a water hazard. There are nets that are nearly 5m long.

        Kalle ball

  • Hi

    I've put Juglans nigra and received a small tree. Now I read here that walnuts are wind pollinated rule.
    Located Juglans nigra the wind-pollinated species? Which in this case means I should get to a tree because I live in the woods and there are no other walnut trees in the surrounding area…or?

    • And, it is true that all the walnuts are wind pollinated. The advantage is that different species within Juglanssläktet can pollinate each other. Then there are the interesting feature of some walnut trees that they can pollinate themselves if they are completely alone. However, no property can be predicted, so it is safer to be turning to a tree.

  • Hi,
    I have planted two walnut trees in Småland two years. # m great now and liver.
    A developing good foliage and the other semre7 perhaps because of transplanting last year.
    What should I use for fertilizer? The land is very lean here and I want to help those on the right track.
    GRATEFULLY,
    Maria

    • Fun with walnut – what kind it is? I usually put some mulch around the plants (ca 10 liters biennial) I cover with wood chips. It has given very good results.

  • Interesting reading about the walnut tree. I have three walnuts from Manchurian walnut, I can plant them and hope it will be a small tree?
    Beginner. Grateful for answers..
    May

  • Hi! Interesting reading! I have a big one, gammalt valnötsträd av någon sort 🙂 Blir massor av nötter, men jag har aldrig lyckats torka dem. Hur ska jag göra?!
    Mvh Marie Axmarker

    • Hi! Är det äkta valnöt du har? Regardless, it is best to remove the green skin and then dry the nuts in 25-40 degrees for two days, To reduce the moisture content so much that they stay for years.
      /Philipp

      • The clear green bark must be removed;;
        Then I put those on large platter or deny
        No problem to dry?
        It is the delicacy to eat the fresh
        I almost long for the taste:
        When they are not bitter like dried
        Regards
        Maria

  • I am about to buy a genuine walnut trees.
    At the nursery they had at least 4 varieties with different properties.
    Then I start to get in years, I might just have the energy to care for my
    garden 10 year. What kind should I choose that quickly harvest, men
    that has “good nuts”.
    Birgitta

    • Hi! Which varieties are what the nursery offers? It also depends on whether the plants are from seeds or grafted. Grafted trees should produce fruit for maybe 5 years if they have been handled properly, while the seedlings can 10 years, but it all depends on the cultivation zone, växtplats etc..

      • The kind I've looked at is Juglans regia Broadview, ca 3 m high. Was little hesitant about this because it was the nut could be a little bitter. Juglans regia Heisenheim kunde man ta hem (til spring). Have Googled much, but could not hitt information about the specific variants. Grateful to have your advice.

        • Forgot to say that I will plant my walnut tree very sheltered south facing in Gothenburg area.

        • excuse the late reply! Unfortunately I have no personal experience of the varieties you mention. Are you sure you want to have a 3 m large tree at once? The establishment becomes more difficult when the. There are several good nurseries have many different varieties of walnuts, bl.a. westergaards.dk, agroforestry.co.uk and achtplagennuts.nl/?item=sortiment.

          • Hi, I live in Malmö and two walnuts wearing very fruit.
            Have planted two Småland highlands of Småland
            and they seem to thrive even if vintrana is nödiga.
            Have bought 2-3 meter high from good åplantskola Malmö called Palette. Can really recomend. They are very good and kuniga. You could call and ask.
            Spring is always difficult with plants
            and if it is not too cold, maybe you could now test whether they are in the pot? I would bet on to plant now
            if you plant now, you could buy those foam rubber tubes for heat pipes and dress on stamen. costing 15 SEK pc. I usually do and works bra.Då will not stamen cold first winter.
            greetings
            Maria

          • Thank you Maria o Philipp for answers!

            Googled the nursery tips, but is not so mytcket safer for the. How does the nursery trees in Denmark and the Netherlands in my neck of the woods.
            Must call to the nursery in Malmö and ask them for advice. Good tips with protection for the tribe.
            Why do not you think that it is good to plant in the spring Maria? Do you know what your walnut trees are varieties of Maria?

          • No, I do not know what kind of grade I.
            Spring is always much worse for plantings.
            The palette of Malmo is very good!
            Wire from Denmark or N-L cope very well
            In your neck of the woods. They survive in the highlands of Småland. If they are in the pot to get the planter that even now, now former, it will snow and the ground freezes. It is good to plant more trees then you nuts previous.
            I have planted even in December Japanese körtkbärs trees and they live
            Regards
            Maria

  • Hey what can you take for walnuts. if you want to sell those kind of restaurants?

    A friend said that they are sure interested in locally grown walnuts?
    We believe we have black walnut, How can you tell what it is the type of beef?
    We have looked o clip brought pictures o so! We think it looks that way!

  • We have a bushy black walnut trees in City Park in Sala. Can be sample-related plants or just a. As 7 high M. Did not know what it was for variety but I was aware when I broke it with a hammer! have learned to dry them to remove the shell without being black. If there is only one plant, it must surely be self-fertile because there are miles and miles to the next walnut.

  • Discovered today a Juglans Nigra in Bulltoftaparken in Malmo. Read here to be able to eat nuts. Should the drought in their skins or without? Can you get a nut to germinate? Has driven apricot trees from the core and love experiments in the garden.

  • Super nice reading!
    Thought swing past Solhaga in Kristianstad at the weekend to buy a tree to the cottage in Huaröd, it is enough zone 2-3 then it is a bit higher situated and had frost on the grass last weekend when we were there.. Is it too late to plant this weekend, you may be doing something extra to improve the odds?

    • thanks! In your zone, it is probably quite easy to plant this late. You can cover the soil around the plant with fir branches and / or leaves to give it a little extra protection. Otherwise, it is important that it is on a well-drained site. Good luck! /Philipp

    • No, it is not! I have my walnut in zone 4
      And last year, many nuts and large the tree is young;) no year / but summer huh very poor. You could cover the soil with leaves or such circular blanket you can buy on Lidel
      That is for plants. Self drive me to such
      Uses Protection strain ä made of foam and means for moving – that they will not freeze – is very cheap and you can reuse the.
      Walnut is not good for deer or hares so there is no danger; but other trees and shrubs. They mumsat 16 newly planted trees with me and wooden Japanese salary shrubs… not kidding
      Regards
      Maria

  • We have a Juglans regia (age variant) our plot of Hammaro in southern Varmland. The tree is about 25 years and provides some years, as 2018, plenty of nuts that we share with squirrels, magpies and crows. 2019 however, was in disrepair so then only got the animals nuts. There are walnut trees in several places in Hammarö, but quite far from us, so I do not think that wind pollination is needed for our tree. I have not intentionally sown, but the pile of leaves are off the tree, I usually find and take care of the nuts cave. “All walnuts nuts sit in bunches on this picture.” it is in the image above. It's not for my tree, nor on the images that come up at a googling of Juglans regia. We have a little problem with the attack of any kind, or maybe just poor fruit development, and in some nuts, it just becomes discolored goo. Anyone know why?

    • Hi;) I have two pieces of walnut trees in Malmo. 2018 had many nuts but small. Think this is due to water shortages and heat. This year was the size
      Better yet it rained more. I have two young trees in Småland highland zone 4. Last year we had quite a number of the tree is very young. This year it was 0! Not a single. I think it depends very on the climate and the cold, winds
      Etc. This year it was raining with very strong winds. First two years I have clothes trunk in a dress that protection. against the cold. We see next year.
      I think water and cold are two important factors.
      This with gegiheten do not know. One can speculate; you live on the island and if the tree is older might reach the roots to the salt water?? I do not know how deep is the walnut roots?
      greet
      Maria

    • You are absolutely right that the caption is unclear. Generally, it is true, however, that the nuts of Juglans sit in clusters. The image is a Japanese walnut (Juglans ailanthifolia) belonging to the species that form the largest clusters of up to 25 nuts per cluster. Juglans regia usually do not produce as large bunches, more normally 1-5 nuts formed from each inflorescence, depending on how successful pollination is. The attack that you're writing about could be caused by a moniliasvamp, if you can send a picture, I can look at it more closely.

  • Vi har en valnötsträd i tomten som är 7 years old, vet inte vilken sort, it gives no walnuts, what to do to give walnuts?

    • It is not unusual that it takes more than 7 years of a walnut before giving fruit. Then it may also need cross-pollinated. If it blooms in the spring and do not give fruit in the fall may be that the lack of pollinators.

  • Is there any way to get hold of (buy) buartnut/heartnuts or a small tree here in Sweden?
    My wife and I are salubrating 4 years as married in about a month and I have made it a habit of giving her something heartshaped with the material of the year. First it was cotton which lead to me learning how to make a Heart from cotton thread, then it was paper so I turned to origami, last year it was leather so I made her a leather heard, but this year it’s fruit… Fruit of all things.
    When I found out about the heartnut or buartnut which are both kind heartshaped I figured a nut is “kind of a fruit”, but man… How the hell do I find one?!

    • There are a few nurseries that sell these in Sweden, but none of them sent by post what I know: Putt Myra nursery in Stjärnsund (my nursery), Svartbäckens garden outside Uppsala and Räveboda nursery in Urshult.

  • Jag har som så många andra fått lära mig att äkta valnöt, J regia, does not thrive in Sweden but here you should invest in other species. Your article, several nurseries and my own garden (and zone II, Mälardalen) contradicts that statement. I have two of these trees, one is higher than the house and should be planted sometime in between 50- and the 70s when the resident here originated in Hungary and tried to plant plants she was used to from home. The second tree is younger with a bushier type of plant but grows year by year. Both trees provide plenty of fruit. What is the interest in finding new commercial varieties?? Could be fun about one “Swedish tribe” customer established.

  • Hi!
    We want to plant a walnut tree on our plot on Öland. Have seen several here that have trees and get plenty of harvest. Is there any variety that is particularly suitable for Öland? Have seen that you can buy trees that are 3,5-4,5 m high, is it a good idea or better with less?

  • Hi, do you have any suggestion for which species of walnut would be suitable for growing in zone 4 a few miles north of Uppsala? A tree that starts producing fruit within a reasonable amount of time would be preffered 🙂

    Ungefär i norra uppland, nära kusten

  • Hi! Have a neighbor who planted a walnut tree from Croatia many years ago. He does not know what the variety is called but they are a little hard to crack. Would like help with name, thanks

  • Hi,

    I am looking to buy a walnut tree to grow in the Vaxjo region, so the South of Sweden, could you advise me what a suitable type of walnut tree is and where I would be able to buy it in Sweden.
    Thank you
    Myrena

    • It is easy. Just see around in your gardenshop what kind they have.
      I planted two 4 years ago on the Highland zone 3-4 and it was 4 meter High trees.
      I got few nuts next year after planting.
      I leave in Kråkshult which is higher than you and it is working: I have bought them in Malmö
      At Paletten, a very good plant shop. You have to call and check.
      Recommend to buy a big trees and plant it in sunny spot to avoid wind as much as possible.
      Good Luck!
      Maria
      Ps I do have a bigger tree in Malmö about 10 m high; if you want you may get it from me for free as I have too many big trees. But you have to dig it yourself and transport from Malmö to Växjo. I assume it has a deep roots but give a lot of nuts,,

  • So fun to read, we have walnut trees up here in Örnsköldsvik / Höga Kusten, several pieces in fact and they have been bearing fruit for several years!

  • Hej allihopa! I was sitting and admiring a walnut tree in Helsingborg while I was waiting for a friend. Then I heard a bunch of nuts fall down. Managed to find 3 st that were whole and some cracked that I pliockadevmed me. Put them in a pot with damp paper outdoors until tomorrow. What should I do to be able to make them germinate?
    Would love to sow your own walnut tree. Then I have always dreamed of a walnut tree for my bonsai collection. But as I asked before How should I sow them for best results?
    Regards
    Lars ludwig

    • Hi Lars-Ludwig,
      you can put the nuts in moist sand in a sealable freezer bag and store it in the fridge over the winter. Then you can sow the seeds in March / April and then most should germinate.
      Best regards, Philipp

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