Where do walnuts grow

Contents

Twenty reasons to consider planting walnut trees

Fig 1. Walnut tree

Note Number: AG1394
Published: December 2009
Updated: May 2013

One of the ongoing challenges facing the tree fruit industry is for orchardists to operate profitably. Drought, high water prices, climate change, spring frosts and hail, high retail and export standards, high cost of production, the high Australian dollar leading to cheaper imports and more costly exports, cannery quotas and intake reductions of fruit are just some of the issues confronting orchardists.

History

History has shown that orchardists are enterprising and willing to trial crops other than the traditional apples, pears, peaches, plums and cherries. While some exotic crops, such as nashi pears and pomegranates may benefit the most tenacious of growers, orchardists might consider growing walnuts, which offer a multitude of benefits. For more than 150 years, walnuts have been grown successfully in southern Australia. Walnuts do not require pickers or a trellis system, are not prone to frost damage, do not need netting, are not perishable and do not need to be cool stored.

Twenty reasons why growing walnuts could be a positive endeavour

  1. Present projections of costs and returns indicate that walnuts will have a positive cash flow five years after planting.
  2. The cost of trees is about the same as trees of any licensed fruit variety.
  3. Walnut trees are free-standing – no trellis is required. Staking young trees may be required in areas that are not protected from strong winds.
  4. Excellent varieties on precocity-inducing rootstocks are now available in Australia.
  5. Densities of between 500 (5mx4m) and 660 (5mx3m) trees/hectare are possible to induce early precocity and obtain high yields.
  6. The ‘central leader’ system of growing walnuts permits a uniform tree complexity, high light interception per hectare, and good light distribution throughout the canopy for sustained production.
  7. Medium to light-textured soils, such as the duplex soils in the Goulburn Valley are suitable and will provide some vigour control. Hilling-up of topsoil is required for surface drainage and good soil structure.
  8. Inducing branching, general vigour control, and maintaining fruitfulness similar to fruit trees has already been researched and can be implemented.
  9. Advice is available on how to manage a high density walnut planting and how to increase precocity without the use of a size-controlling rootstock.
  10. There is minimal risk of frost damage to flowers and nuts, because walnut trees bloom in late November.
  11. No honeybees are required, because walnuts are wind pollinated by polliniser trees.
  12. Walnuts are mechanically harvested and processed.
  13. A factory to process walnuts has been established in Violet Town in north-central Victoria.
  14. Mature walnut trees under micro-irrigation need approximately 6 megalitres of water per hectare.
  15. Pest and disease pressures of walnut trees are much less than for fruit trees.
  16. Walnuts are not affected by fruit fly quarantine regulations.
  17. Walnuts in shell have a long storage life.
  18. Walnuts have health and cosmetic properties.
  19. Walnuts have excellent export potential.
  20. The wood of walnut trees also has commercial value.

Further references

Australian Walnut Industry Association

Acknowledgements

The information in this note was developed by Harold Adem, AWIA and Bas van den Ende, Advanced Horticulture, Consultant.

It was reviewed by Steven Lorimer, Farm Services Victoria. December 2009.

ISSN 1329-8062

Published and Authorised by:
Department of Environment and Primary Industries
1 Spring Street
Melbourne, Victoria

This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968.

The advice provided in this publication is intended as a source of information only. Always read the label before using any of the products mentioned. The State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication

Growing Hardwoods

Walnut trees grown for the nut industry are usually open-grown trees with large crowns to produce a high volume of fruit, versus timber trees with a narrower crown producing straighter trees with fewer limbs.

Paul Wray, Iowa State University, Bugwood.org

Walnut trees should begin producing nuts regularly on a good site when they are 8 to 10 years old or 15 to 25 feet tall. Many black walnut trees may bear only irregularly or during alternate years, but you can select those trees that regularly bear when you thin the plantation.

Several cultural factors can influence flower production, fruit set, and fruit maturation. Because female flowers are formed within the dormant buds when the current year’s nuts are rapidly enlarging and filling, the immature flowers must compete with the nuts for carbohydrates produced by the leaves. Cultural practices such as fertilization increase the number of new flowers formed in the buds.

To provide the nitrogen needed for good fruit set, walnut plantations should be fertilized according to their cropping potential. For every 100 pounds of freshly husked nuts harvested approximately 15 pounds of nitrogen must be added either though nitrogen-based fertilizers or legume cover crops. Moisture stress, especially during July and August when the nuts are rapidly enlarging and filling, will drastically reduce nut production and quality. Be sure that your trees get the moisture they need. See Growing Black Walnut for Nut Production for more information.

Harvesting Nuts

A bushel of freshly collected nuts weighs about 48 pounds and contains about 375 nuts. To keep the nuts from overheating and losing kernel quality, spread freshly collected nuts out in shallow piles until husked. Wear rubber gloves when handling nuts because the hulls contain chemicals that can irritate and blister the skin. Husked nuts can be stored in open mesh bags and allowed to air dry. Nuts to be used for seed must be kept moist and prepared for stratification. Nuts are usually purchased on a green hulled weight basis by local agri-business firms who are supplied with walnut hullers by walnut processors. Harvested nuts can be sold to local nut hulling operators in your area in October. After husking, about one-third of a bushel of nuts weighing 18 pounds will remain.

Evaluating the Nuts

When managing a plantation for nuts and timber, you should evaluate the nuts from some of your best trees. Trees that consistently produce nuts with more than 4 grams of kernel, kernel percentages higher than 20 percent with more than 50 percent of kernel extracted as quarters, and fewer than 20 percent blind nuts are worth further evaluation and possible propagation as new cultivars for timber and nut production.

This information was adapted from Walnut Notes, J. W. Van Sambeek, author.

Missouri Center for Agroforestry supports the nation’s most comprehensive research programs for developing the eastern black walnut as a nut crops for agroforestry practices. Their research includes developing improved nut cultivars with higher yields and better flavor.

The Northern Nut Growers Association, Inc. (NNGA) brings together people interested in growing nut trees. Their members include experts in nut tree cultivation, farmers, amateur and commercial nut growers, experiment station workers, horticultural teachers and scientists, nut tree breeders, nursery people, foresters, and beginning nut culturists.

Harvested black walnuts are processed into nutmeats. Black walnut extract flavoring is also made from nuts, as well as black walnut ice cream and other desserts. The shells are used in the abrasives industry. Hammons Products Company of Stockton Missouri is the primary US producer of nutmeats and abrasives made from black walnuts.

Health information

Black walnuts are recognized as one of the most healthy tree nuts, low in saturated fats, high in unsaturated fats, and a source of protein (24.1 grams in the edible portion of 100 grams of Black Walnut food), the nutmeats are also a source of Vitamins A, iron, minerals and fiber.

Are your walnut trees veneer or timber quality?

Are those walnut trees growing on your farm high-value veneer logs, or just timber? That’s a question many landowners ask themselves, because the difference in value is several hundred dollars per log. In some cases, a little management ahead of time can help a landowner gain top veneer grades.

“A typical walnut veneer tree is a large tree usually at least 20 inches in diameter or larger at breast height, or about 4½ feet above ground level; has no or very few defects; and is tall and straight,” says Rocky Hayes, Missouri Department of Conservation forestry regional supervisor.

VENEER LOGS: This load of veneer walnut logs was harvested from a managed timber stand near Cape Girardeau, Mo., last year. “Bigger trees have more board-feet volume, so there is more value,” says Rocky Hayes, forestry regional supervisor at the Missouri Department of Conservation. (Photo: Rocky Hayes, MDC)

“Bigger is better when it comes to diameter,” he explains. “Bigger trees have more board-feet volume, so there is more value. The most valuable trees I’ve seen in my 35-year career have been over 30 inches in diameter and larger.”

For example, a black walnut that is Grade A veneer at 19 inches diameter will be worth about $700 or $800. If you add another 6 inches of diameter, that price can nearly double.

Defects make a big difference in value when it comes to veneer. “Defects include limbs, knots, cracks, holes, mineral streaks, forked trees, wire or metal embedded in the tree, bird pecks, growth rings that are too wide or inconsistent in texture, crooks, sweeps, and anything else that causes imperfections in the wood,” Hayes says. “I’ve seen some odd things in trees like glass telephone insulators and deer antlers that were attached or hung on the tree, and the tree grew around it. Needless to say, these are all defects.”

It takes management to get to the high-value walnut lumber. “Grow your walnut on good soil and prune off lower limbs early in the life of the tree up to at least 16 feet in height,” says Hayes. “Over half of the value of a tree is in the butt log.” At least 9 feet of clear trunk is required to make good veneer grade. He also suggests keeping livestock from grazing around the trees and causing injury.

“Plant good genetic stock and grow the trees in forest condition, rather than in the open,” he recommends. “Less than 1% of all naturally grown trees without management are veneer quality, so that is why they are so valuable,” Hayes adds. “Management greatly improves the chances of growing a veneer quality tree.”

You can learn more by contacting Hayes at [email protected]

How often do Black Walnut Trees bear fruit ( not too often I hope!!)

In April 2015 we moved into a home that has a 150 foot tall, 140 year old Black Walnut Tree. Last fall the tree had almost no walnuts. Last fall we also had the tree pruned and the canopy brought up several feet to take off dangerous limbs that were over the roof of the house. This year we have literally thousands of huge black walnuts and they drop all over the lawn beneath, make big holes in the lawn and then if we don’t pick them up right away they turn black and are making a huge mess and destroying our lawn. They get smashed when we run the riding mover over them that we use to cut the lawn and suck up the millions of leaves that are falling now . I am curious why the tree had no nuts the first fall and now has so many. Do these trees only bear fruit every other year? That would be great, No nuts ever would be even better! We love the beautiful tree but it is really a lot of work so we are curious about how often we will have to deal with this. Thanks as always, you have been so helpful.

Black Walnuts

The two major varieties of walnuts grown for food in the U.S. are black walnut (Eastern black walnut, Juglans nigra; and California black walnut, Juglans hindsii); and Persian walnut (Juglans regia), also called Carpathian walnut or English walnut. Eastern black walnut is native to North America and is a valuable timber tree, long harvested for veneer lumber. Black walnuts also have a long history as a food ingredient, and Eastern black walnuts are one of the few wild-harvested commercial food crops in the U.S. Persian walnut trees were introduced in California by Spanish missionaries in the 1700s, and California dominates U.S. commercial Persian walnut production. This profile focuses on Eastern black walnut for nut production.

Marketing

Nut crops are suitable to be added to many farm marketing plans, especially direct markets such as farmers markets, community supported agriculture or subscription sales, and on-farm stands. Eastern black walnuts are also widely collected throughout Kentucky and surrounding states for wholesaling to hulling stations. Black walnut nutmeats are used in baking, ice cream, candies and other food preparations. State and federal food safety, labeling and other food manufacturing regulations, including allergen concerns, may apply when shelling nuts and making food products containing tree nuts. Hulled and cleaned in-shell black walnuts have also been used in some arts and crafts products. Black walnut buying and hulling stations each fall purchase in-hull black walnuts gathered from native trees in yards, woodlots and forests.

Production

Walnut trees grow best in deep, well-drained soil with medium to good fertility. The University of Kentucky recommends a soil pH of around 6.5; black walnuts can thrive in soils with a pH slightly higher or slightly lower than this. Sites for nut orchard establishment should have soil with good water holding capacity. Supplemental watering or irrigation may be necessary during establishment, especially dry years, as walnuts do not do well in drought conditions. Walnuts may be planted from seed, seedlings, or grafted trees. Seeds must be stratified before planting. Trees started from seeds or seedlings should be grafted to the desired variety. Grafting black walnuts is more challenging than for most other nut trees; grafted trees will produce nuts faster but may be more expensive or less available. Proper soil fertility, hole preparation and weed management will improve the likelihood of superior tree growth during establishment.

See the full crop profile and other resources below:

Abstract:
Persian walnut is the most important temperate nut grown in India. It is mainly grown in Jammu & Kashmir, Himachal Pradesh, Uttar Pradesh and Arunachal Pradesh. Total area under walnut is 67053 hectares with annual production over 71758 metric tons. Most plantations are of seedling origin and are in scattered form which produce nuts of variable quality. Breeders over the years have exploited the variation amongst these seedling trees to select superior genotypes with desirable traits. Besides, improved cultivars were introduced from other countries and after evaluation, some recommendations have been made. On the whole, walnut has remained a low priority crop in otherwise apple dominated regions. Walnut growing suffers from lack of suitable methods of propagation, inadequate vegetatively propagated plants, lack of standard rootstocks/ cultivars, problems of re-establishment of nursery plant in the orchard, specific climatic requirements, pollination behaviour and lack of suitable pollinizers, long juvenile period and harvesting. The progress made in the recent years to overcome the above cultivation problems with a view to revive the walnut industry with export potential has been discussed.

Planting Walnut Trees: Tips and Information On Growing Walnuts

Walnut trees produce not only a delicious, nutritious nut but are used for their wood for fine furniture. These beautiful trees also provide shade in the landscape with their large, arching limbs.

How to Grow a Walnut Tree

Most growing walnut trees attain heights of 50 feet with an equivalent width and can be found throughout the United States. The English or Persian and black walnuts are the most common, used for nut production as well as shade trees. A mature tree will produce 50 to 80 pounds of nuts yearly.

The Persian walnut is grown in California and is prized for its large nuts. There are several cultivars such as:

  • Hartley
  • Chandler
  • Serr
  • Vina
  • Ashley
  • Tehama
  • Pedro
  • Sunland
  • Howard

All leaf out late in the spring, thus avoiding walnut blight. Persian walnuts are adapted to Mediterranean climates with mild winters and are not suitable for some areas.

Cold hardy cultivars of the Juglandaceae family include:

  • Cascade
  • Butternut
  • Heartnut (Can be grown in the Pacific Northwest or the mid-Atlantic and southeastern United States and are known as Carpathian type.)

Choose a variety suited to your climate. Growing walnuts require 140 to 150 days with temperatures over 27 to 29 F. (-2 to -6 C.) for the earliest ripening varieties.

Planting Walnut Trees

Once you have made your selection, it’s now time for planting the walnut tree. Till a 12 square foot area down to the depth of at least 10 inches to remove any grass, weeds or other plants that compete for the new trees water and nutrients. Then, dig a hole 1 to 2 inches larger than the walnut seedling’s root ball.

Put the seedling in the hole to the same depth as the pot or bury the roots 1 to 2 inches below the soil. Fill in the hole and tamp down to eliminate any air pocket around the roots.

Water the tree in until moist, not soaked. Mulch the surrounding area with organic mulch, like wood chips, bark or sawdust, to retard weeds and maintain moisture. Keep the mulch 2 inches away from your new tree.

Walnut Tree Care

Walnut trees have an extensive root system and as such do not need to be watered often — only if the top 2 inches of soil have dried out.

Prune any dead or damaged limbs as the tree matures; otherwise, there is no need to prune. Add mulch as needed each spring.

Harvesting Walnuts

Be patient. Walnut trees won’t start producing nuts until they are about 10 years old, with peak production around 30 years old. How do you know when to start harvesting walnuts? Persian walnuts are harvested at the beginning of shuck split — when the seed coat has turned a light tan in color.

Depending upon the size of the tree, commercial producers use trunk or limb shakers and a windrow pushes the nuts into rows to be picked up by the sweeper. For the home grower, old fashioned shaking of branches and hand picking from the ground is probably the best method for harvesting walnuts.

Nuts need to be dried by laying them out in a squirrel free area for a few days. Dried nuts can be stored for about four months at room temp or frozen for one to two years.

English Walnut Tree Growing Tips

The English walnut tree, also called the Persian walnut or common walnut, is prized for its hardwood and delicious, nutritious nut. Follow these tips to plant an English walnut tree in your yard. These nuts will be easy to harvest and shell, providing you with delicious nutrition right outside your house.

When to Plant an English Walnut Tree

The best time to plant an English walnut trees in the springtime after the last frost. For a walnut tree to survive, it needs to planted in a climate that has at least 190 days of frost-free weather, so don’t wait around too long after the last frost in the spring to plant. If growing from seed, the seed will need to be stratified (kept in cold temperatures) for at least 3 months prior to planting. Store the seeds in a refrigerator under 40 degrees and keep in a ziploc bag.

Where to Plant an English Walnut Tree

Plant in an area where the walnut tree can receive full sun for about 8 hours a day, making sure the tree has plenty of room to grow. English walnut trees should be planted in well-draining soil with pH level of 6.0 to 7.5.

How to Plant an English Walnut Tree

Dig a hole twice as large as the root ball, a little wider than it is deep. For best results, work several gallons of peat moss and other compost materials into the back fill. Place the seedling in the ground, spreading out its roots. Place enough backfill with compost into the soil to hold the seedling steady. Water deeply, then fill with the rest of the soil. Be sure not to plant higher than the original soil level on the seedling. If in doubt, it is better to plant too shallow than too deep.

For the first 2 years of growth, make sure your tree is receiving at least 1 inch of water a week. Apply mulch around the tree in the autumn, keeping the mulch several inches from the tree trunk. English walnut trees respond well to organic fertilizers. Applying a mulch of manure every autumn may be enough, although other organic fertilizers like bone meal are also beneficial.

Why to Plant an English Walnut

Plant an English walnut for its beauty and shade. An English walnut is a large tree, reaching maturity at 60 feet after 20 years of growth. If growing more than one walnut tree, make sure you give each tree plenty of room to grow tall and wide, spacing them about 60 feet apart. The English walnut tree will begin producing nuts around 5 to 10 years after planting.

Paul Alfrey from the Balkan Ecology Project covers the hows and whys of growing Walnuts – Juglans regia – https://balkanecologyproject.blogspot.com.au/2015/11/the-essential-guide-to-everything-you.htm

If I were to tell you of an apocalypse proof asset that is 100% guaranteed to increase in value, both in the short (3 yrs) and long term (300 yrs), will contribute to your good health, provides aesthetic pleasure to your surroundings, has the potential to replicate itself exponentially and has parts that can be dipped into smooth melted dark chocolate, covered in cocoa powder and eaten, surely you’ll be chuffed to learn that I’m referring to none other than Juglans regia – The Walnut tree.

The essential guide to everything you need to know to grow walnuts

At the moment I’m struggling to think of a better thing to do than to plant a walnut tree, other than to plant more than one walnut tree:) So here I present the Essential Guide to Everything you Need to Know about Walnuts.

During this article we’ll be focusing on the Persian Walnut – Juglans regia first providing an overview of the plant followed by advice on where to plant, how to care for, uses of walnuts and a look at some good companions plants for walnuts. We’ll also profile three productive and disease resistant Walnut cultivars that we are offering from our forest garden plant nursery.

Overview

Juglans regia is known by several common names including Persian walnut, common walnut, English walnut, Carpathian walnut and Madeira nut. The natural range of this plant is from the Carpathian mountains through the middle east and into the Himalayas.

Description

Walnuts are fast growing trees that develop broad canopies reaching 18 m width and 30 m in height. It is a light-demanding species, requiring full sun to grow well.

A walnut compound leaf.
photo from – www.tree-guide.com/common-walnut

The buds awaken from winter dormancy in mid April – late May (depending on cultivar) and leaf fall occurs in early November. The large compound leaves give off a lemon /lime scent particularly when crushed. The flowers open before or around the same time as the leaves and you can find both male and female flowers on the plant (monoecious). The male flowers are slender catkins and the female flowers are smaller often found on the tips of the branches. Pollination is carried out by the wind.

Growing Range

Walnuts from the middle east and the Persian strains, are hardy to zone 5 (-23 °C) while the Carpathian strains can withstand temperatures as low as -32 °C (zone 4). You can’t grow these plants in the lower latitude areas without at least 500-1500 hrs per year of temperatures below 7 °C. At high latitude climate the young shoots and flowers are susceptible to frost damage in the spring, and early frosts in the autumn can cause damage to new shoots.

Pollination

Walnuts have both male and female flower parts on the same tree (monoecious). The pollen is shed from the male flowers and should settle on the females flowers. The pollen is physically very small and light and can travel quite some distance. Studies have shown in certain orchards that wind blown pollen came from trees over a mile away.

Juglans regia – Female and Male Flowers

If the pollen from the male flower settles on the female flower at the point that they are receptive, fertilisation is likely to occur and the female flower will go on to develop into nuts. The time of pollen shedding from the male flower does not always overlap well with the time of female flower receptivity to pollen. This condition is referred to as dichogamy. To overcome this problem growers can select another walnut cultivar (a pollinator) the male flowers of which open at the same time as the female flowers from the main cultivar. The pollinator should be situated upwind from the main crop. If you have other walnuts upwind from your site you should not have problems with this.

Nearly all commercial orchards are co-planted with a pollinator variety to ensure the main crop gets enough pollen to set nuts. The recommendations for optimal pollination in an orchard environment is to plant one row of pollinators for every 8 main crop rows and to plant the row of pollinators upwind.

In some cultivars Walnut fruits form on the tips of the new seasons growth on other cultivars the fruit is formed on the lateral shoots.

Lateral Bearers

Lateral bearing cultivars bear fruits on lateral buds of shoots and are generally of higher productivity than terminal and intermediate bearers due to the larger number of fruit buds on these plants.

Terminal/Tip Bearers

Terminal bearing cultivars bear fruits on the tips of the shoots.

Tip bearing cultivar from a tree at our market garden site

Propagation

Walnut trees commonly reproduce in the wild and are very easy to grow from seed. A tree grown from seed will start to produce fruit in 8 -12 yrs, it’s not certain that it will share the characteristics of the parent trees. Walnut cultivars are grafted and will start to fruit in the fifth year. Seeing as most cultivars are 2 yrs old when you buy them, the trees can start to bear fruit on the 3rd year after planting. (for expected yields see below)

Where to Plant

Location – The best locations for walnut trees are sunny, relatively sheltered sites. Frost pockets should be avoided.

Soil – The ideal soil is a deep, fertile, well drained loam with a pH between 6 and 7 (4.3 – 8.3 tolerated), although I’ve seen magnificent specimens growing in heavy clay on the river banks and trees tolerating a wide range of soil conditions.

Inhibitors – Walnuts produce a growth inhibitor – juglone – that has a detrimental effect on some species of plants growing nearby (negative allelopathy). Experimental studies have shown that juglone can inhibit plant respiration, depriving sensitive plants of needed energy and reducing the plants ability to uptake water and nutrients. There are many plants that do not seem to be affected by juglone (see below)

Comfrey ‘Bocking 14’ growing in the shade of a 20 year old Walnut

Walnut Pollination – When planting your walnut it’s important to consider a pollination partner if you would like to maximise your yields. (see above)

Fertility, Irrigation and Care

Fertility – It’s advisable to not add compost to the roots of walnuts when planting out and to add just a little top dressing compost to your newly planted trees. In the 2nd year, adding around 10 L of compost to the base of the tree in the spring will meet the plants growing nitrogen (N) demands. Too much N makes the trees more susceptible to Walnut Blight.

Irrigation – Should not be necessary unless rainfall is below 600 mm per year and is uneven in distribution throughout the year. In my climate in South-East Europe, Bulgaria I give my young trees 20 L once every two weeks during the summer months. Never use a sprinkler or hose to water and avoid splashing water onto the leaves as this will promote the development of Walnut Blight.

Weeding – Its important to keep the trees free from weeds whilst they establish as young trees are intolerant of competition especially from grass. Mulching the trees annually with card and straw will work well but take care to keep the collar free from mulch to prevent it from rotting.

Potential Problems

Sunburn: can occur in excessive summer heat (38C) and the kernels can shrivel and darken. This is more so of a problem if the tree is under moisture stress.

Cold injury: Young trees are very susceptible to frost damage. Flowers can be destroyed in early frosts so it’s important to select late flowering cultivars if your planting site experiences early frosts.

Walnut Blight on our garden trees following an unusually wet spring and summer of 2013

Walnut uses

Beyond the nutritious delicious nuts the other parts of the Walnut plant can be used for a variety of purposes.

Timber – The timber is very stable, hardly warps at all and after proper seasoning swells very little. The wood is straight grained, quite durable, slightly coarse (silky) in texture so easily held, strong, of medium density and can withstand considerable shock. It is easy to work and holds metal parts with little wear or risk of splitting. The heartwood is mottled with brown, chocolate, black and light purple colours intermingled. Some of the most attractive wood comes from the root crown area from which fine burr walnut veneers can be obtained.

Nuts – Nuts can be eaten raw, salted or pickled. Nuts must have an oil content of at least 50% to store successfully, nuts with 30 – 50% oil content have a higher moisture level and tend to shrivel in storage, so must be eaten immediately or preserved,

Oil – Can be pressed from the ripe nuts (sometimes over 50% by weight of kernels). The oil can be used raw, for cooking or as a butter substitute.

Leaves – Leaves can be used to make a wine.

Sap – The sap of the tree is edible, in the same way as that of the sugarmaple.

Medicinal uses – Several parts of the tree have medicinal uses. The leaves and bark have alterative, laxative, astringent and detergent properties, and are used for the treatment of skin diseases; in addition the bark is a purgative. Leaves should be picked in June or July in fine weather, and dried quickly in a shady, warm, well ventilated place.

-The juice of the green husks, boiled with honey, is a good gargle for sore throats.

-The oil from nuts can be used for colic and skin diseases.

-The husks, shells and peel are sudorific, especially when green.

Other uses – The green husks can be boiled to produce a dark yellow dye; the leaves contain a brown dye used on wool and to stain skin.

The oil has been used for making varnishes, polishing wood, in soaps and as a lamp oil.

The leaves have insect repellent properties; in former times horses were rested underneath walnut trees to relieve them from insect irritation.

Walnuts uses section from Martin Crawford’s Agroforestry News Volume 1 Number 1 – Persian Walnuts

Walnut Yields

Walnuts grown from seed may not provide any nuts until they reach sexual maturity at 10 – 13 years of age. Grafted cultivars generally start to fruit in their 5th year. Most grafted cultivars are 2 yrs old so you can expect to receive the first crops in the 3rd year after planting. Below is a table showing the estimated yields of a walnut tree over time.

Companion Plants for Walnuts

Walnuts, along with hickories, produce the chemical juglone, which is exuded from all parts of the plant. This chemical can inhibit the growth rate of nearby plants, a phenomenon known as negative alleopathy. This combined with the heavy water demands of larger trees and the deep shade cast in high summer presents challenges to effective companion planting but much can be grown in the under story during the first 15 – 20 years

20 yr old Walnut in our Garden with Sambucus nigra, Aronia melanocarpa and Pyrus cv. doing very well

Juglone Toleranace

Here’s alist of plants that have been observed to grow well under walnuts and are considered tolerant to Juglone. Bear in mind that few plants have been experimentally tested for sensitivity to juglone.

The plants highlighted in green are species I have personally observed growing seemingly unhindered in and around the under story of Juglans regia

Walnuts from our Gardens

Many factors affect sensitivity, including level of contact, health of the plant, soil environment, and the overall site conditions. Aside from juglone, a mature walnut will cast a very heavy shade and young sun demanding plants will not survive in these conditions. The list provided here is strictly a guide and should not be considered complete or definitive.

Plant Tolerance to Juglone : Juglone Tolerant Plants

If you have experience of plants growing well under and around a Juglone producing plant that are not on this list, please share in the comments section below.

Walnut Cultivars – Hardy and Resistant to Major Pest and Diseases

Below you can find profiles of some Bulgarian cultivars that we have on offer at our Bio-nursery. These cultivars are high yielding and resistant to common walnut diseases.

We are currently offering these cultivars at ​​ €22 per tree with 10% discount for orders over 10 trees. Delivery all other Europe

For other disease resistant walnut cultivars see Agroforestry Research Trust.

Walnut cultivars for Permaculture and Forest Gardens

Cultivar – ‘Izvor 10’

•Fruiting – The fruit forms on lateral buds and ripen around mid September. Excellent tasting oblong nuts with a thin shell. The nuts weigh around 10 g have a high fat content – 55.7%.
•Disease Resistance – Excellent resistance to Walnut anthracnose and Walnut blight
•Form – The tree forms a broad, relatively thin crown
•Hardiness – A very hardy cultivar tolerating temperatures down to -25 – 30 ºС
•Flowering Period – Late

Cultivar – ‘Sheinovo’

•Fruiting – The fruit forms on the tips and ripen around mid September. Excellent tasting nuts that are easy to remove from the thin shell. The nuts weigh around 12 -13 g and have a high fat content – 71.4% .
•Disease Resistance – Good resistance to Walnut anthracnose and Walnut blight
•Form – The tree is vigorous with a wide spread crown
•Hardiness – A hardy cultivar tolerating temperatures down to -24 ºС
•Flowering Period – Mid – Late

Cultivar – ‘Dryanovo’

•Fruiting – Fruits for on the tips of branches and ripen to very large 14 – 18 g round nuts. The fat content is 67.39%.
•Disease Resistance – Very resistant to anthracnose, though very susceptible to blight.
•Form – The tree is vigorous with dome shaped crown
•Hardiness – A hardy cultivar tolerating temperatures down to -24 ºС
•Flowering Period – Mid – Late

To order some walnut cultivars for delivery this winter contact us at [email protected] or via the website; https://www.balkep.org/

Nuts of any tree of the Juglans genus are called walnuts. A walnut cannot be described as a true botanical nut since it is actually the seed of a drupe or drupaceous nut.

There are two major species of walnuts, the English walnut, and the black walnut. The former is also known as the Persian walnut since it originated in Persia. The latter traces its origin to North America. The English hybrid is grown on a commercial scale and numerous cultivars have been developed over time.

Walnuts usually grow well in cool climatic conditions. The yield of the crop is adversely affected by high temperatures. An evenly distributed annual rainfall of about 800 mm generates an optimum yield of the crop. Walnuts grow best in well-drained deep silt loamy or clay loamy soils.

Top Walnut Producing Countries

China

China is the world’s biggest producer of walnuts. In the year 2016/17, the country produced 1,060,000 metric tons of walnut. China accounted for about 50% of the total walnut production in the world. The country is also the world’s biggest consumer of walnuts. The per capita consumption of walnuts in China has steeply grown from only 0.17 kg in 1995 to 1.8 kg in 2016. China’s 24% growth in per capita walnut consumption rate is well ahead of the global average of 5.8%.

The United States (US)

The US ranks second in walnut production in the world. The country accounts for nearly one-third of the global production of walnuts. California in the US is the country’s top walnut producing state. In fact, the state accounts for nearly all the walnut production of the US. The Sacramento and San Joaquin Valley regions in California are famous for walnut production. Nearly 4,900 farmers in California grow walnuts. In 2016/17, the US produced 607,810 metric tons of walnut.

Other Major Walnut Producing Nations

China and the US account for nearly three-quarters of the global walnut production. The European Union, Ukraine, Chile, Turkey, and Moldova are the other top regions/countries for walnut production.

Uses Of Walnut

The primary use of walnut is as food. Walnuts can be eaten on their own or added to a dish or food item like muesli, walnut pie, walnut soup, walnut cake, etc. Walnuts are also used in the preparation of folk medicines although little evidence pointing towards the efficacy of such treatments. Walnuts are also used to produce ink and dyes and for some other applications.

Things You Might Not Know about How Walnuts Grow

Walnuts as Fruit?

For the sake of communicating, botanists and horticulturists divide vegetation into different categories. They categorize fruits and nuts differently. A fruit is what contains a plant’s seeds and according to the experts (who haggle over the specifics), walnuts count among the stone fruits known as “dry drupes.”

What’s a Dry Drupe?

A dry drupe has a fixed peel covering an inner shell that contains a single seed. Every walnut possesses a green outer hull, wrinkly shell and edible kernel. But anyone whose only encounters with walnuts are at the grocery store has never seen one with its outer hull intact.

The Boom-or-Bust Growth Cycle

Every walnut begins as a flower and every flower begins as a bud. But, because walnut buds don’t bloom until their second summer, many never reach the harvesting stage. Why? Both black and English walnut trees are known for fruiting heavily one year and being nearly barren the next. Why does this happen and what’s a walnut grower to do?

Alternate Bearing

Alternate (or biennial) bearing happens because, in heavy years, walnut trees divert most of their energy to their developing crop. Very little goes to buds destined to bloom the following summer. It’s called bud suppression, and it’s one way the trees have of compensating for poor growing conditions.

Managing Biennial Bearing

Breaking a walnut tree’s alternate bearing habit takes time, but it’s the best method of ensuring a respectable crop of nuts each year. Effective measures include:

  • Thinning the fruit buds in the early spring of bumper-crop years. The reward is two years of average harvests instead of a boom-and-bust cycle.
  • Thinning the developing walnuts at one-third of their mature size when bud removal isn’t possible. This improves the off-year harvest, but not as much as thinning the buds.
  • Planting trees with a record of bearing evenly every year, such as the black walnut cultivars ‘Chandler’ and ‘Howard.’
  • Planting zone-appropriate trees. Depending on cultivar, English and black walnuts are suitable for USDA zones 3 though 7 and 4 through 9, respectively.

Expert gardener’s tip: Early-spring fertilizer and supplemental water during drought also help break the cycle.

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