Tuesday, 29 August 2017

Mo' Mulberry - The Essential Guide to all you need to know about Mulberry

Not many plants offer so much to the grower while demanding so little in return. A tree that requires so little attention and care, that even if there were an RSPP - Royal Society for the Protection of Plants (which there should be judging by the amount of tortured house and garden plants I come across)  no-one would ever get prosecuted for Morus neglect :)

Mulberry for Permaculture/Polyculture and Agroforestry  

Mulberry is one of the fastest growing temperate trees I know of,  produces an abundance of excellent fruit every year and is virtually pest and disease free.  It is one half responsible for the finest fibres known to man, i.e silk, can be grown nearly everywhere that has soil and is a source of high quality animal fodder plus quite a bit more, as we shall see.

Mulberry fruit from various trees in our gardens. 

During this post we'll take a close look at these incredible plants including how to grow them, the uses of Mulberry, growing Mulberry in polycultures, permaculture and agroforestry and i'll introduce some relatively rare Bulgarian cultivars that we are offering from the bionursery this season.  

Overview


There are about 68 species of the genus Morus, and the majority of them occur in Asia. In China alone there are over a thousand cultivars grown.

We'll be focusing on the White Mulberry - Morus alba that we grow in our gardens and we'll also touch on Black Mulberry - M. nigra and Red Mulberry - M. rubra,  two other popular plants in cultivation. Let's start with an attempt to clarify the differences between these three species and then take a detailed look at White Mulberry.

The differences between Red, Black and White Mulberry 


  • White Mulberry are native to northern, eastern, and central Asia and are one of the primary species used to feed silkworms.
  • Black Mulberry are native to southwest Asia.  It was brought to Europe before the Roman Empire where it has continued to be grown for its fruits.
  • Red Mulberry are native to eastern North America
There is a fair bit of confusion over these three species. The colour of the fruit does not identify the mulberry species. White Mulberries, for example, can produce white, lavender or black fruit. White Mulberry fruits are generally very sweet but often lacking in tartness. Red Mulberry fruits are usually deep red, almost black, and in the best cultivars  have a flavour that almost equals that of the black mulberry. Black Mulberry fruits are large and juicy, with a good balance of sweetness and tartness that I personally prefer the most.

White and Black Mulberry fruit  
Black Mulberry can be distinguished from White Mulberry by a hairy lower leaf surface on the Black Mulberry plants. The juicier Black Mulberry fruit will also stain your fingers when you pick them. The fruits of the White and Red Mulberry are more difficult to tell apart but a sure way of telling the two species apart is from the leaves. The upper surface of the Red Mulberry leaves are noticeably rough, similar in texture to fine sandpaper while in stark contrast the upper surface of the leaves of White Mulberry are lustrous (Glossy, smooth and shiny).

Confusing the situation further, Red Mulberry and White Mulberry often hybridize, resulting in trees with intermediate characteristics.

A parable on the perils of tardiness in the
days before mobiles :) 

According to Ovid  (Metamorphoses - Book IV) you have the Babylonian lovers Pyramus and Thisbe, and the Greek Gods to thank for at least some of this confusion. In short,  Pyramus and Thisbe denied their love of each other by their rivaling families decided to run off together (sound familiar??) The rendezvous was under a White Mulberry tree out of town. Thisbe turned up first and while waiting for Pyramus, a lioness with jaws stained from the blood of a previous kill started towards her. Thisbe darted into a nearby cave dropping her shawl under the tree as she fled. The lioness approached the shawl, dripping blood all over it just as Pyramus showed up. Pyramus chased the lioness away and seeing the blood stained shawl assumed that Thisbe had been mauled to death.  In desperation he plunged a sword into his belly just moments before Thisbe emerged from the cave. Finding Pyramus taking his last breath she falls on the sword herself and they both bleed out in tragic unity. The blood splashing from the bodies stained the previously White Mulberry fruit, and the Gods forever changed the Mulberry's colour to honour their forbidden love. All I can say is thank the Gods for mobile phones :)





White Mulberry - Morus alba 


Latin name - Morus alba
Common name - White Mulberry, Silkworm Mulberry
Family - Moraceae

History - White Mulberry cultivation has a long and rich history dating back thousands of years ago as a requirement for silkworm rearing. They were beloved by Persians, Romans and Greeks and moved throughout Europe along with the spread of culture from these places.

Growing Range -  Morus alba has a very wide distribution range in Asia and Europe (from Korea to Spain, including China, India, Central Asia and the Near East); in Africa (North and East Africa) and in the Americas (from the United States to Argentina, including Mexico, Central America, Colombia and Brazil). The origins of most cultivated mulberry varieties are believed to be in the China/Japan area and in the Himalayan foothills.


Morus alba leaf variation -
 https://en.wikipedia.org/wiki/Morus_alba
Description -  A fast-growing, small to medium-sized tree growing to 10 –20 m tall. It is generally a short-lived tree although there are some specimens known to be over 250 years old.  Fruits can be white at maturity on a few trees, but are usually dark purple and 3 to 6 cm long.  The fruits ripen from mid spring - late summer (depending on species and cultivar).  The leaves are usually shiny, dark green and smooth but can be yellowish green. Most leaves are not lobed, but some can be. The juvenile growth is often lobed.

Sexual Reproduction - The trees can be dioecious or monoecious, and sometimes will change from one sex to another. The flowers are held on short, green, pendulous, catkins that appear in the axils of the current season's growth and on spurs on older wood. They are wind pollinated and some cultivars will set fruit without any pollination. The White Mulberry is notable for the rapid release of its pollen, which is launched at over half the speed of sound!





Mulberry flowers - in some cases the male and female flowers are on the same tree (monoecious) and in other cases the male and female flowers are on separate trees (dioecious).    


Light Preferences -  Mulberries thrive in full sun but can grow well in partial shade.

Water needs -  The plants are drought tolerant but grow best and yield high in areas with rainfall between 600 -1500 mm/yr. In our location with average annual rainfall of 580 mm they grow well without irrigation. I have seen Mulberry growing well in wetlands and on riverbanks, as the plants are tolerant to sporadic water logging although they usually occur in non-wetlands.

Habitat -   Morus alba commonly invades old fields, roadsides, forest edges, urban environments, and other disturbed areas. It grows well in natural forests, planted forests, range/grasslands, ruderal/disturbed areas and urban areas.

Hardiness USDA - 4b - 9a  A very hardy tree tolerating temperatures down to -36C but also comfortable in sub tropical and Mediterranean climates. Morus alba is the most cold resistant of the Mulberry trees

Ecology - Many small mammals feed on mulberries, including birds, foxes, squirrels and rodents. Deer browse on the twigs and foliage and a range of insects inhabit the crowns of mature trees. In our experience Ladybirds are attracted to the Mulberry fruit. Mulberry is often associated with Mycorrhizae including Glomus mosseae and Glomus fasciculatum.     


Where to Plant


Climatic Limitations -  Mulberries thrive over a very wide range of climates especially warm temperate but also Mediterranean,  sub-tropical and tropical, where they can be grown as evergreens.

Soil -  They prefer a warm, moist, well-drained loamy soil in a sunny position. However they are adapted to coarse, medium, and fine soils.  They tolerate a pH range of 5.0-7.0.

Location - The trees are tolerant of wind, drought, cold and partial shade so you can pretty much plant them anywhere. The plant is also quite salt tolerant once established.  A few things to consider when choosing a location is that the fruit fall can extend 6-8 weeks and once mature it's practically impossible to harvest let alone consume all that fruit, so placing the tree in a place where the fruit fall will not be a nuisance is a good idea. Much to the pleasure of our pigs we set their pen under one half of our Mulberry tree with some of the tree overhanging the chicken coop also.

Pig pen located under a mature  White Mulberry - Morus alba in our back garden 


The trees can get large and will cast a heavy shade when mature so this should also be taken into consideration. We lift the lower limbs of our trees to allow space and light for a range of smaller trees, shrubs and herbs (see Mulberry polyculture later).

Pollination/Fertilisation - Some cultivars will produce greater yields if allowed to cross-pollinate, although many cultivars (monoecious types) do not need cross-pollination at all. Some Mulberries can even produce fruit without any pollination. Pollination occurs by wind.

Feeding, Irrigation and Care


Feeding - Mulberry require little fertilisation. When planting out new trees top dressing the planting hole with  20 - 30 L of compost and repeating this in early spring for the first 2 years will be more than enough to get them going. After this they should be fine, especially so if you are growing the tree in polycultures.  

Irrigation - The trees will grow faster and produce more fruit with access to water during the flowering and fruiting period. Young trees should be mulched well each spring and irrigated for the first 2-3  years with 30 L of water every 2-4 weeks without rain. The trees develop deep taproots that should be able to access ground water if available.  
 
Weeding - Mulching plants with a 10 -20 cm deep mulch each spring and pulling weeds that start to grow through in the summer is good practice when the plants are young. As the trees mature they grow well amongst other plants of all kinds.

Pruning -  Mulberry are low branching. We have lifted the lower limbs of our trees to approx 5- 6 m high allowing us to plant under the tree and to allow easy access around the tree. The trees respond well to this type of pruning. If pruning young trees bear in mind the flowering and fruit buds develop on second year old growth.

Harvesting - The easiest way I know of to harvest a White Mulberry is the shake and catch method.

Here's a video made by my son Archie of us harvesting a tree last year



Fresh fruit only keeps for a few days, and is best kept refrigerated if you don't eat them immediately. This is one of the main reasons you don't see much Mulberry fruit in the shops. The fruits can also be dried or frozen (never tried it personally).


Propagation - There are many reports on the internet of how easy it is to propagate mulberry from branches. Simply cut the branch from the tree and push it into the soil and presto! it will root within a season. I've tried this many times with our White Mulberry Morus alba  trees with no success. In fact I have tried hard wood cuttings in every season with no successes. It seems to me that this method is probably effective method for Red Mulberry and perhaps Black Mulberry.

White Mulberry can be grown from seed and is best sown immediately after fruiting. Cold stratification for 4- 16 weeks can improve germination rates. Layering is also reported to work well.

Potential Problems


Invasive - This species is considered ecologically invasive in most of North America. The threat is to the native Red Mulberry (M. rubra) though hybridization. It does not seem to be a problem in Europe.

Pest and Disease -  Mulberries suffer few disease and insect pests. I have never experienced any problems with the Mulberries we grow or any I have seen. It's an oddity that based on this more people do not grow them at home and commercially.  The main pest to Mulberry is probably deer that will browse on the leaves of these plants, but this is generally only a problem with young trees and regrowth from coppice. If you are growing for biomass pollarding the trees at a height the deer cannot reach is a good solution.

Allergies - The plant's pollen has become problematical in some cities where it has been blamed for an increase in hay fever.

Mulberry Uses


Silk Production - The Asian Mulberries are widely cultivated to feed the silkworm - Bombyx mori  employed in the commercial production of silk. Silk was once grown across the world but since it is a very labour-intensive industry much is now focused in countries with low labour costs. China has 626, 000 hectares of Mulberry for silkworm.

Mulberry is usually associated with sericulture, the production of silk through the silkworm (Bombyx mori).

The silkworm is a pretty amazing little creature. Feeding exclusively on Mulberry leaves the caterpillars emerge from eggs and fatten up, spin a cocoon (the silk part) and when not used for silk production hatch into beautiful moths. When used for silk production the caterpillars are boiled to death in their cocoon before they hatch. The boiled cocoons can be eaten and in China and Vietnam they are seasoned and fried.


Original source here

Fruit -  White Mulberry fruits are generally very sweet but often lacking in the tartness that can be found in the Red and Black Mulberries. The fruits ripen over an extended period of time unlike many other fruits which seem to come all at once. The fruiting period can be from 6-8 weeks. 

Wood - Especially in the Indian subcontinent, mulberry wood is used for handicrafts, cabinet work and for sporting woods (e.g. grass-hockey sticks and tennis rackets). The thin branches can be woven into baskets. Coppiced mulberry produces fairly straight strong poles that we use for stakes and tree props. The plant grows very fast and makes a medium-quality fuel wood with a calorific value of 4370-4770 kcal/kg.

Erosion control: A useful species for stabilizing physical soil-conservation structures.

Reclamation: Can be grown on wastelands.

Soil Improver and Biomass: Fast growth and tolerance to pruning makes this a great chop and drop plant. Growth can increase soil fertility through litter fall.

Animal Fodder - As well as the feed stock for silkworms the leaves and branches  make great food for livestock (cattle, goats, pigs and rabbits) and are used across the world especially so in areas with poor soils and low rainfall where fresh forage is not always available. It's often reported that the foliage can be used to feed chickens. Our flock won't eat it.

The leaves contain between 18-25% protein (dry matter content) and have high digestibility (70-90%). Yields of leaves and stems used for forage, range from 3.2-21 tons/acre/year (8-52 tons/hectare/year) with most in the 8-12 tons/acre/year (20-30 tons/hectare/year). If you are interested in growing Mulberry for animals check out this article from FAO.

 Here's another video from Archie of us feeding 2nd year pollard regrowth to our animals.




Leaves -  The leaves are prepared as tea in Korea. The tea can be made from fresh or dried leaves. They are highly nutritious and contain vitamins B complex (except B12), C (200-300 mg/100 g), D and flavonols. They are sometimes eaten as a vegetable.

Landscaping - Their resistance to pruning, their low water requirements and tolerance of pollution make them very suitable plants for urban conditions, house gardens, street shade and city embellishment. They are often grown on roadsides and avenues as an ornamental tree.


The compact Morus alba 'pendula' - Varna Botanic Garden - Ekopark - Universitetska Botanicheska gradina


Hedging / Windbreak - I've not seen or tried these plants in a hedge but I see no reason why they would not be very suitable. They take well to repeated pruning, grow fast and have large leaves that provide a good screen from late spring to Autumn. Being fast growing and in little need of attention White Mulberry is a great option for shelter planting such as protecting orchards from wind.

Bee Fodder - The pollen from the flowers is utilized by bees and other pollinators and sometimes juice of overripe berries or fallen fruit.

Medicinal uses -  The bark is said to be good in the treatment of stomach-ache and the leaves and twigs can be used for treating heavy colds, cough, red eye, insect bites and wounds. The fruit is used in the treatment of sore throat and melancholia. The Chinese have used Mulberry fruit for centuries for its aphrodisiac qualities.


Mulberry Yields


Trees grown from seed will start to fruit in the 5th or 6th year. Cultivar whips should start to fruit in the 2nd or 3rd year.

Younger trees can be expected to yield between 3 - 5 kg  in the first 2 - 4 years when fruiting begins. A mature tree of 20 -30 years will produce well over 300 kg of fruit.

To harvest the trees we hold a net under and shake the branches. As the fruits ripen at different stages starting in early June and ending in early August inevitably you shake down some unripe fruit but the majority of the fruit is in good condition.

Harvesting Mulberry with nets in our garden     

If you coppice or pollard the tree you will need to wait a year before they start to produce fruit again as the flowering buds are borne on the second year growth.


Mulberry Coppice/Pollard 


Mulberry is the one of the fastest growing temperate trees I know of. The wood is relatively strong and the small diameter poles make good stakes and larger diameter poles are good for fuel logs. The trees respond very well to coppicing and pollarding. If you have deer pressure in your area pollarding is best as the regrowth is out of reach.

We keep a few trees in the garden as pollards and regularly cut the regrowth back for the rabbits and pigs. We pollard as opposed to coppice as the trees are planted among a density of fruiting shrubs (Blackberry, Raspberry, Aronia and Goji).   Other trees we allow to grow larger and cut back on a 5 year cycle to provide fuel logs and poles for vegetable supports and fence posts.  

There is a rich history of mulberry coppice in Asia and it's becoming more popular across the world as a biomass producing plant particularly for animal food.

Mulberry leaves as a forage crop for livestock including monogastrics (pigs, rabbits, etc.), ruminants (cattle, sheep, goats, etc.) Our pigs and rabbits enjoy it, but our chickens and ducks are not into it.

 Coppice shoots from a 20 year old stool have showed a mean annual diameter increment of 1.5 cm and a mean annual height increment of 1 m. Early growth is very fast: 4.5 m in the 1st 2 years. Currently we have multiple regrowth shoots of 2.5 - 3 m tall in one year from the tree pollarded in the above video. To get an idea how fast these trees grow that tree was 8 years old (from seed) and has been pollarded 3 times to date.

Mulberry Polycultures


Mulberry are excellent plants for use in polycultures. They are tolerant of partial shade so suitable in the edges of an under storey of a larger tree, are not very nutrient demanding or competitive. They tolerate pruning very well and can be used for chop and drop plants grown between fruit trees or in hedgerows. If fruit production is priority they can be given a position in full sun and although they grow tall and wide, by lifting the lower branches you can accommodate a range of productive and useful plants underneath them.

Perhaps one of my favorite polycultures in our home garden features a grand old Mulberry tree - Morus alba. The tree is approx. 10 m tall and 12 m wide. As previously mentioned the mulberry overhangs the pig pen and some of the chicken coop. The slow but sure delivery of  fruit fall for 8 weeks in the spring and summer is much appreciated by the animals.


Sketch of our White Mulberry Polyculture

On the edges of the canopy we have a fig tree and a Cornelian Cherry that both produce exceptionally well and we have planted a few hazels on the south side last year.

Figs and Cornelian Cherry from the Polyculture 

Directly under the Mulberry tree there is an Apple and a Pear tree. Both trees are semi standards but the shade of the Mulberry has resulted in the trees taking on a dwarf habit. The Apple produces a negligible quantity of small red fruits (we keep it as it serves as part of the electric fencing in the pig pen) but the Pear tree on the western side of the tree produces a reasonable quantity of delicious Pears.

Pear Tree with the White Mulberry Towering overhead  

Under and around the Pear we grow  Asparagus plants with Chinese Lantern and Tuberous Comfrey ground cover and we have a few black currant plants. Finally there are two patches of Raspberry one to the north of the tree and one on the eastern edge of the canopy.

Raspberry with the pear and Mulberry in the background

We also have 4 raised beds to the east of the mulberry where we grow tree saplings that appreciate the shade of the Mulberry during high summer.

Tree seedling beds under the mulberry. You can see the lifted  Mulberry canopy on the top left corner of the photo  

I'll be making a detailed write up of this polyculture in the near future.

Agroforestry Potential Of Mulberry 


There is great potential for Mulberry in agroforestry systems. It's deep-rooting habit and drought tolerance makes it a suitable tree for Alley cropping with grains grown in between alleys. The fast growing nature of the tree and it's tolerance to wind makes it great candidate for windbreaks and biomass belts. Furthermore the high quality animal fodder that can be produced from the trees make it an excellent choice for silvoarable systems although the fodder is generally cut and carried as the plant is not suited to continuous grazing.

We'll be experimenting with optimal cutting intervals in our upcoming perennial polycultre trials growing the biomass for fodder and for mulch material.

I've included mulberry in a few agroforestry designs the most recent being an alley cropping system with single row mixed contour plantings (with Hazel and Pea Tree). The alleys in between the rows will be used for free ranged pastured poultry and growing grains for the poultry.  


26 m stretch of a polyculture tree row for an alley cropping design for Catherine Zanev's farm in Debnevo, Bulgaria   


Mulberry Cultivars 


We have some great mulberry cultivars on offer this season. The cultivars have been developed in Bulgaria and are suitable for all climates where Mulberry grows well. We have a selection of heavy cropping plants as well plants grown for biomass/animal fodder or sericulture. All of these plants are resistant to all major pest and diseases.

The price is €12 per tree and we are offering 10% discount for orders over 30 trees.

Mulberry cultivars -  Fruiting Plants 



White Mulberry -  Morus alba -  'Vratza 24' 


Fruit - Abundant large purple fruits ripening from June - August
Sex and Pollination - Dioecious - Female Plant will produce fruit with a male pollinator such as 'Kokuso 27' or any fruiting mulberry nearby
Hardiness - Full hardy withstanding temperatures as low as -34 C
Leaves -  Large entire leaves (22 cm x 19 cm). Thick and nutritious
Fodder Potential -  The leaf yield under rain fed conditions with planting distance 3 m x 1 m, 3300 trees per hectare is higher than 13,000 kg/ha.
Water needs - Very drought tolerant


White Mulberry -  Morus alba - 'Vratza 18'


Fruit - Abundant Large purple fruits ripening from June - August
Sex and Pollination - Dioecious - Female Plant will produce fruit with a male pollinator such as 'Kokuso 27' or any fruiting mulberry nearby
Hardiness - Full hardy withstanding temperatures as low as -34 C
Leaves -  Large entire leaves (29 cm x 21 cm). Thick and nutritious
Fodder Potential -  The leaf yield under rain fed conditions with planting distance 3 m x 1 m, 3300 trees per hectare is higher than 14,000 kg/ha.
Water needs - Very drought tolerant 

Kagayamae Mulberry - Morus kagayamae - 'Kinriu'


Fruit - Abundant large black fruits ripening from June - August
Sex and Pollination - Dioecious - Female Plant will produce fruit with a male pollinator such as 'Kokuso 27' or any fruiting mulberry nearby
Hardiness - Full hardy withstanding temperatures as low as -34 C
Leaves -  Large entire leaves (25 cm x 19 cm). Thick and nutritious
Fodder Potential -  The leaf yield under rain fed conditions with planting distance 3 m x 1 m, 3300 trees per hectare is higher than 16,000 kg/ha.



Mulberry cultivars - Biomass and Fodder Plants 


These plants have been selected specifically for vigor and their huge nutritious leaves.


Large leaved mulberry, great trees for biomass production for sericulture, mulches and animal fodder   


White Mulberry -  Morus alba - 'Kokuso 27'


Fruit - Fruitless
Sex and Pollination - Monoecious - Majority male flowers
Hardiness - Full hardy withstanding temperatures as low as -34 C
Leaves -  Large lobed leaves (22 cm x 17 cm). Thick and nutritious
Fodder Potential -  The leaf yield under rain fed conditions with planting distance 3 m x 1 m, 3300 trees per hectare is higher than 16,000 kg/ha.

Japanese Mulberry - Morus latifolia - 'Kokuso 21'


Fruit - Fruitless
Sex and Pollination - Monoecious - Majority male flowers
Hardiness - Full hardy withstanding temperatures as low as -34 C
Leaves -  Large entire leaves (23 cm x 17 cm). Thick and nutritious
Fodder Potential -  The leaf yield under rain fed conditions with planting distance 3 m x 1 m, 3300 trees per hectare is higher than 15,000 kg/ha.


Click here to view website 


€12 per tree

To order some Mulberry cultivars for delivery this winter contact us at balkanecologyproject@gmail.com - 

Tracked and recorded delivery to anywhere in Europe 




Keeping in Touch 


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We offer a range of plants and seeds for permaculture and forest gardens from our plant nursery including a range of fruit and nut cultivars. Delivery to all over Europe available from Nov - March












References

http://www.fao.org/docrep/005/x9895E/x9895e02.htm
http://www.fao.org/ag/agp/agpc/doc/gbase/data/morusalba.htm
https://en.wikipedia.org/wiki/Morus_(plant)
https://en.wikipedia.org/wiki/Morus_nigra
https://en.wikipedia.org/wiki/Morus_alba
http://tcpermaculture.com/site/2015/06/02/permaculture-plants-mulberries/
https://www.invasive.org/weedcd/pdfs/wow/white_mulberry.pdf
http://www.wildones.org/wp-content/uploads/2012/09/BeyondtheBirdFeederPart8.pdf
http://www.worldagroforestry.org/treedb/AFTPDFS/Morus_alba.PDF
http://www.biologydiscussion.com/invertebrate-zoology/silkworm/mulberry-silkworm-history-habitat-and-life-cycle/27659

Saturday, 29 July 2017

The Amazing Hazel - The Essential Guide to Everything you need to know about Hazels

Hazel is a multi purpose champion of a plant that is super easy to grow, produces delicious nuts, pliable wood that can be crafted into a variety of products, provides early fodder for bees and an encouraging spectacle when flowering during the mid winter.

What more can I say.... a plant so good people started naming their daughters after it.


Hazel - Corylus spp, 

When we speak of Hazel  we are generally referring to two species, Corylus avellana and Corylus maxima. The two species produce slightly different shape nuts and take different growth forms.  Corylus avellana produce Hazelnuts and Corylus maxima produce Filberts. There are 14–18 species in the Corylus genus but many of the European cultivars we have nowadays are Corylus avellana, Corylus maxima or the result of hybrids between these two species. This post we will focus solely on these popular nut producing species.

The leafy bracts that envelope the nuts are the easiest way of telling the species apart. 

During this post we'll take a close look at these versatile plants, including how and where to grow them, growing them in polycultures, how they can be used in agroforestry systems, coppicing hazel, and we'll look at some of my favourite hardy productive and disease resistant cultivars that we are offering from our Bionursery.

Overview


Latin name - Corylus avellana, Corylus maxima
Common name - Hazel, Hazelnut, Cobnut, Filbert, Spanish Nut, Pontic Nut, Lombardy Nut.
Family- Betulaceae


History -  Pollen counts reveal that Corylus avellana was the first of the temperate deciduous forest trees to immigrate, establish itself and then become abundant in the post glacial period. Humans have been enjoying hazels since prehistoric times and it is thought by some that hazelnuts provided a staple source of food before the days of wheat.  Evidence of large-scale Mesolithic nut processing, some 9,000 years old, was found in Scotland and Hazels have been used extensively across the temperate zone throughout all civilizations.
   


Corylus avellana - Common Hazel



Description - Corylus avellana - Grows as a small tree or large shrub commonly reaching heights of 5 m with a 5 m spread, but sometimes can reach twice that height and takes a tree like form. The leaves, that open in late April and May and fall in November, are almost circular with double toothed edges and a short pointed tip. The leafy bracts are shorter than the nut.


Description - Corylus maxima - Grows as a large shrub 6 m high with a 5 m spread. Resembling C.avellana but with young grey twigs, glandular and bristly leaves that are wider, longer catkins and leafy bracts that are tubular and closed twice the length of the nut. The nuts are also longer than C. avellana     

Both species are monoecious . The male flowers are encased in catkins that brighten up the landscape in the winter. The female flowers are tiny red tassels that emerge from buds on the stems.  





Sexual Reproduction - As mentioned above the plants are monoecious, producing male and female flowers on the same plant.  The male flowers are held in catkins that form during the previous summer and open in the dead of winter and flower through to early spring. There are around 240 male flowers in each catkin and these produce the pollen. Give the catkins a flick in late February to see a small cloud of pollen erupt. Contrary to the wonderful spectacle of the male flowers, female flowers are almost invisible unless you are actively looking for them. They are tiny individual flowers, visible only as red styles protruding from a green bud-like structure on the same branches as the male flowers.
A wind pollinated plant, the pollen from the catkins blows to reach the female flowers. If successfully pollinated and fertilized the female flower will grow to become  1- 4 nuts C. avellana  or  1 - 6 nuts C.maxima .



Growing Range - Corylus avellana is native to western Asia, north Africa and most of Europe, from British Isles eastwards to Russia and the Caucasus, and from central Scandinavia southwards to Turkey. Corylus avellana is native to the Balkans and Asia Minor but is widely naturalised elsewhere.

Both species are pioneer plants found in a range of habitats. As a component of ancient forests they prefer moist lowland soil and are often found growing in the shade of deciduous trees, especially oak. They can be found in hedges, meadows and pastures, on the banks of streams, waste places, abandoned plantings, the edges of woods, on steep slopes and by paths and roadsides. Hazel grows naturally up to altitudes of 700 m

Hazelnut-producing regions of the world are all close to large bodies of water, which moderate the climate. About 70% of the world’s hazelnut production comes from the black sea region of northern Turkey. Italy produces about 20% of world production. Spain, France, Georgia, Azerbaijan, and the United States produce most of the rest.

Hardiness USDACorylus avellana – Zone 4-8
                              Corylus maxima – Zone 5-8

Ecology - Hazel flowers are an important source of pollen for bees and other pollinators. The pollen-bearing catkins can be available to pollinators from as early as late January - late March. Hazel leaves are used as food plants by the larvae of various species of Lepidoptera. The nuts are used by dormice to fatten up for hibernation and in spring the leaves are a good source of food for caterpillars, which dormice also eat. Hazel nuts are also eaten by woodpeckers, nuthatches, tits, wood pigeons, jays and a number of small mammals.

Where to Plant


Climatic limitations  - Both species crop best in areas with cool, moist summers and mild cool winters or in maritime climates. Areas with high summer temperatures are not ideal although good cultivar selection can improve results. Areas with extreme winter cold can also be problematic. The shoots of the plants are hardy to -29 C (-20 F) although winter temperatures below -10 C (-13 F) during the flowering period may damage the male flowers reducing the likelihood of fruit set that year.    
The plants will not grow well in tropical or sub tropical climates and require a winter chilling period of 800 - 1200 hrs below 7 C (45 F) which is similar to apples.

Soil - Hazel tolerates a wide variety of soils from calcareous to acid, loam to clay and prefers soil that's well drained and fairly low in nutrients; overly rich soil gives plenty of leaf growth at the expense of flowers and nuts. Hazels will not grow well in water logged and peaty soils. Shallow soils will restrict the growth and height of hazel.

Location - If growing for nut production in cold climates you should avoid planting in frost pockets, and in hot climates avoid windy sites. Hazelnut trees also cannot tolerate excessive heat or a long dry season. A sheltered area with a reliable source of irrigation is essential in hot climates.

Pollination - Hazels are wind pollinated. As mentioned above cold weather (-10 C and under) during the flowering time can destroy flowers and reduce fruit set. Heavy rain during the time where pollen is being released can also suppress the amount of pollen carried in the air and moist conditions destroys pollen viability.  

The plants are in theory self fertile meaning the pollen from the male flowers can pollinate and fertilize the female flowers on the same plant. However, the blossoming times of the male and female flowers on the same plant do not always coincide and for this reason it is recommended to plant 2 or more different cultivars to increase the likelihood of pollination occurring. Wild growing hazel nearby will serve as good pollinating agents for most cultivars and there are many cultivars that work well together to ensure fuller cropping. There are some cultivars that absolutely require pollinating partners so research your cultivars well  A good rule of thumb for how many pollinator plants you need to support you main cropping cultivar is 1 to 18. On sites where wet weather is common during the flowering period this can be increased. The pollinating partner should be a maximum of 45 m away and upwind from the main cropping plants.

Pollen is released from the male flowers in bursts across a 4- 6 week period in January - March. Interestingly, the pollen germinates as soon as it reaches a receptive flower but the fertilization process does not take place for another 4-5 months in June. Once fertilized the female flowers develop into nuts very rapidly with 90% growth occurring within 4 - 6 weeks.            


Fertility, Irrigation and Care 


Fertility - On good soils hazel will not need fertilisers. On poor soils, planting out with 30 L of compost (applied to the surface) and mulching well with straw and repeating this each spring for 4- 5 years will provide a good boost to growth. Planting nitrogen fixing companions can also be very effective.

Irrigation - In cooler climates such as the UK irrigation is not necessary. In warmer climes with hot summers and long periods without rain, applying 30 L of water per tree every 3-4  weeks without rain and mulching well is very effective.  

Weeding - Mulching plants with a 10 -20 cm deep mulch each spring and pulling weeds that start to grow through in the summer is good practice especially when the plants are young.

Pruning -  When planting out single stemmed whips it's good practice to prune the top down to 45 cm to encourage lower branching (a practice known as formative pruning).  Hazel plants often sucker (send up many shoots from the base of the plant. Suckering growth should be removed to keep the stems clear and the crown less congested.  Beyond formative pruning and removing suckers we don't prune our Hazels but there is a tradition, as with most fruit trees,  to prune in order to achieve an open centered goblet shaped bush.

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A classic pruning example practiced in commercial hazel orchards

If you are going to prune than it's important to know that female flowers (that will form the nuts) are produced from buds on growth from the previous seasons growth. For optimal nut production you should aim to have plenty of previous years stems  at least 15-25 cm long.  

I read an interesting comment regarding a traditional pruning method used to increase nut production called 'brutting'. This involves prompting more of the trees' energy to go into flower bud production, by snapping, but not breaking off, the tips of the new year shoots' six or seven leaf groups from the join with the trunk or branch, at the end of the growing season. I'll be trying this on a few of our plants this year.



Harvesting - The nuts are fully ripe when the husks begin to yellow and can be picked by hand. Nuts will naturally drop over a 4-6 week period. It's important to not pick before they are ripe as they will shrivel and do not keep well.


Layering and Stooling 

Propagation - We have grown hundreds of hazels from locally gathered seed and this is a very easy and reliable method to propagate these plants. Most of our seedling stock we use for coppice plants and hedging plants. For nut production we use cultivars as they generally fruit within the 3rd and 4th year after planting and you know what kind of nut you will end up with.

Seedlings can take up to 6 or 7 years to produce nuts and you never know what they will be like. Saying that, we have some great nut producing seedlings that we propagated from local plants. They appear to be more resistant to the winter cold and have been providing a reliable crop each year even after bitter cold late winters.

Another great way to propagate hazel, including cultivars that are grown on their own roots, is by stooling and layering. Stooling involves heaping soil at the base of the plant, leaving it for 12 months and then dividing the rooted stems. Layering is burying the stems in the soil for 12 months and cutting them off the main plant once the stem has rooted. Hazels that are grafted onto their own roots will send up suckers. The suckers can be dug out in the winter and planted on. The suckers can be a nuisance and will need cutting back to promote better production. Corylus colurna - Turkish hazel is often used as a rootstock as these are non-suckering and have a deeper rooting habit. Cultivars on Corylus colurna rootstocks are often very vigorous.





Potential Problems


Excessive Heat: Hazelnut trees cannot tolerate excessive heat or a long dry season. They are especially sensitive to drying in windy conditions.

Cold injury:  Although a very hardy plant, when growing for nut production the trees are vulnerable during the flowering period in early - late winter. Temperatures below -10 C (-13 F) during the flowering period will damage the male flowers and destroy the pollen reducing the likelihood of fruit set that year. Because not all catkins elongate at the same time, crop damage usually is minimal if there is only a brief cold spell.

Insect/Pest: Grey squirrels are major pest of hazels. Nut weevils - Balaninus nucum can destroy the maturing nuts. Beetles lay eggs in the immature nuts. The eggs hatch into maggots that eat the maturing nut and bore out of the shell to pupate in the soil where they overwinter before hatching, mating and laying more eggs in the next crop. Clearing up the fallen nuts is good way to control this pest. Running chicken under the hazels in September can also disturb the pupae in the soil.  

Nut Weevils - Balaninus nucum Photo from - https://www.flickr.com/photos/eric-dutoit/5956692789


Disease:  In the US this species is affected by Eastern Filbert Blight (EFB), which is caused by the fungus Anisogramma anomola and is fatal to trees. However EFB can be controlled by a variety of management strategies and does not present a major threat to the species as a whole.
Bacterial Blight - Xanthomonas campestris pv. corylina causes leaf spotting, dieback of branches and in worst cases death. Trees under stress are most susceptible.  

Suckering - Hazels can sucker profusely and the suckers need to be cut back to allow an open crown and avoid congestion. There are cultivars that do not sucker, generally those grown on the Corylus colurna root stocks.

Allergies: The pollen of hazel species are often the cause for allergies in late winter or early spring,

Hazel Uses


Beyond the nutritious delicious nuts hazels can be used for a variety of purposes.

Wood  - Hazel is almost as well known for coppicing as it is for its nuts. The poles from coppice (known as 'wands') are long and flexible and have traditionally been used for wattle fencing, thatching spars, walking sticks, fishing rods, basketry, pea and bean sticks and firewood. The wood is soft and easy to split but not very durable (See Hazel Coppice below).

Adding value to the coppice material 


Oil -  The nut oil is used as edible oil and contains 65% of a non-drying oil that can be used in paints, cosmetics etc.

Animal Fodder - The twigs can be used to feed rabbits and goats all year around and the leaves are very palatable to cattle.

Leaves - Leaves contain on average 2.2% N. 0.7% K and 0.12% P and when applied as mulch make a great fertilizer. The plant has potential to be grown as chop and drop component in a polyculture system.

Hedging - Hazel makes a great hedge taking well to trimming and providing a dense screen. Nut production is not as high as when grown as free standing plants but some nuts can be harvested from the hedge. The plants are also tolerant of wind and a 2 or 3 row windbreak can be set up where alternate rows are coppiced on a 7 year cycle.

Bee Fodder - Hazel is an excellent source of early forage for bees providing a source of pollen from February through to March. We include hazel in our Early Polleniser Polyculture, a polyculture dedicated to providing an early source of pollen/nectar to a wide diversity of pollinating insects.

The Early Polleniser Polyculture 


Medicinal uses - The leaves are used in allopathy: their effect is to stimulate circulation and bile production, and they are used for liver and gall disorders. Hazelnuts are rich in protein, monounsaturated fat, vitamin E, manganese, and numerous other essential nutrients.

Other uses - The finely ground seeds are used as an ingredient of face masks in cosmetics.


Hazelnut Yields


Hazelnut trees can produce a few nuts when they are 2 or 3 years old, but they are not considered commercially productive until 4 years of age and reach peak production from years 10 - 15.  Mature orchards can produce 1 -3 metric tons per ha. An orchard can remain productive for about 40–50 years if managed well and kept free of disease.


Yield per mature treeYield per acre
4050 m2
Yield per Ha
10000 m2
Average Production  3-5 kg880-1760 lbs1-2 tonnes
Max Production11 kg2640 lbs3 tonnes



Example of Coppice - http://www.greenwaytreecare.co.uk/images/Coppicing2.jpg

 Hazel Coppice 


Hazel coppice has been practiced extensively in the past and still provides an excellent source of valuable wood especially if you are adding value with wood crafting.

Contrary to what you may expect, coppicing the hazel can extend the life of the plant considerably with some well managed coppices being centuries old.

Hazel can be grown on various coppice cycles for a supply of poles ('Wands') that are used for a variety of purposes as listed above. A 7 - 10 year rotation is often practiced and is planted out at a rate of 1500 - 2000 plants per ha (spacing is 2.2 - 2.6 m between plants).
 In the 7th - 10th year the shoots should be 4-5m long and can be cut at any point during the year apart from August but is usually carried out in the winter. If you cut the coppice in the summer, leaves from the wood make an excellent cattle feed or mulch.  Regrowth will quickly reestablish and is vulnerable to browsing from wild and domestic animals. After the first few coppice cycles, regrowth will be fast but after 15 years it will decline.  If a hazel coppice is not well managed i.e cut at regular intervals for 40+ years  it will die back.

How much wood can be harvested? - A site with 1500 plants per ha can yield 20 tonnes of dry wood or 40 m3 of wood per ha per cycle.

Hazel coppices are often combined with standard trees to make a two storey forest. Sweet Chestnut is a classic combination in the South of England. Oak is also very commonly grown  with hazel at a rate of 30 - 100 standard trees per Ha. Too many standard trees will shade out the hazel.    

Hazel (in the middle) with standard Sweet Chestnut trees in the background 

Hazel Polycultures 


Hazels are excellent plants for use in polycultures. They are tolerant of shade so suitable in the under storey, are not very nutrient demanding or competitive and are relatively compact and easy to manage. They tolerate pruning very well and can be used for chop and drop plants grown between fruit trees or in hedgerows. If nut production is sought after they should be given a prime position but can still accommodate a range of productive and useful plants around them.

We have used hazel in various polycultures including living hedges, main crop contour plantings and habitat polycultures.

Here's an example of a design with hazel planted in a polyculture hedge.

I included hazel in a mixed species living hedge I designed for Permaculture Orchard - Orehite Ranch - Veslec

We'll be planting out Hazel in our new trial garden - Ataraxia, where we are growing it along with asparagus, currants, wild garlic and various bulbs in 1.5 m wide beds.



Here's a short list of ground cover and bulbous plants that we observe growing well with hazel.



Agroforestry Potential Of Hazels 


There is great potential for hazels in agroforestry systems. Traditionally, in Europe, hazels were grown in a silvopasture system with sheep grazing the pasture beneath the trees, this has an added benefit of controlling suckering growth. Hazel has also been grown with vines and in Kentish orchards gooseberries and currants were traditionally inter planted with young hazel.

I've included hazel in a few agroforestry designs the most recent being a 30 ha pastured poultry system where we're using hazel amongst mulberry planted on contour.


 

Being shade tolerant the trees are good candidates for use in an under storey. In deep shade the plants will not produce a significant yield of nuts but they can be used for coppicing or mulch production. In partial shade they can still produce good yields.

Hazelnut cultivars - Hardy and Resistant to Major Pests and Diseases


There are hundreds of hazel cultivars throughout the world, not to mention the hybrids, American and Chinese species or the Trazels, Filazels and Hazelberts (perhaps a topic for another post).

Most cultivars belong to Corylus maxima but there are many Corylus avellana and many grafted onto Corylus colurna rootstock. When selecting cultivars for your garden there a few things to consider.

  • flowering times - to avoid cold damage in the winter choose a late flowering cultivar 
  • suckering behaviour -  to avoid pruning work or perhaps if growing for mulch or biomass this could be desirable
  • size and vigor - to select the right size plant for your garden   
  • pollinator partners - to facilitate larger and more reliable yields 



Below you can find profiles of some excellent cultivars that we have on offer at our Bionursery.

We are currently offering cultivars at ​​ €5.3 per tree with 10% discount for orders over 20 trees. We also have 2nd year Hazel seedlings for hedgerows, biomass, pollinating partners etc for €4 per plant.

Looking for a supply for your orchard and farm?  For larger orders please send us an email and we will provide you with a quote.




Corylus avellana - 'Ata Baba'
  • Fruit - Round medium size fruits of 1.4 g grouped in clusters of 3 or 4 . Ripen in mid August
  • Pollination - Self fertile
  • Hardiness - Full hardy withstanding temperatures as low as -34 C
  • Disease Resistance - Corylus colurna root stock which has a high resistance to the main European pests attacking hazelnut crop
  • Form - Bush variety, very vigorous multistemmed and flowering early towards the end on December

Corylus avellana - 'Ran Trapezundski'
  • Fruit - Great tasting large oval fruits with thin shells that ripen at the end of July
  • Pollination -  Not Self fertile - Pollinated by Rimski, Bademoviden and Atta Baba
  • Hardiness - Full hardy withstanding temperatures as low as -34 C
  • Disease Resistance - Corylus colurna root stock which has a high resistance to the main European pests attacking hazelnut crop
  • Form - Bush, medium vigor, multi stemmed, fruits abundantly.

Corylus avellana - 'Rimski'
  • Fruit - Large rounded nuts about 2.7g. Thin shell. 67% fat content. The fruits ripen in mid August
  • Pollination - Not Self fertile - Pollinated by Bademoviden and Ran Trapezundski
  • Hardiness Full hardy withstanding temperatures as low as -34 C
  • Disease Resistance - Corylus colurna root stock which has a high resistance to the main European pests attacking hazelnut crop
  • Form - Bush variety. fast growing, multi stemmed with an upright crown.

Corylus avellana - 'Tonda Gentile'
  • Fruit - Excellent flavour, med - large round nuts of 2.5g with a thin shell
  • Pollination - Not Self fertile - Pollinated by Rimski, Bademoviden and Ata Baba 
  • Hardiness Full hardy withstanding temperatures as low as -34 C
  • Disease Resistance - Corylus colurna root stock which has a high resistance to the main European pests attacking hazelnut crop
  • Form - Moderate growth rates and can be grown as single stemmed trees

Corylus avellana - 'Cosford'
  • Fruit - The nuts have hard shells.100 g of fresh nuts contains 13 g protein, 61 g fat, 13,7 g carbohydrates and 3.5 g fiber. They mature in late September.
  • Pollination - Self fertile, a good pollinator for many other Hazels, a good choice if you are starting your own nut orchard.
  • Hardiness Full hardy withstanding temperatures as low as -34 C
  • Disease Resistance - Generally disease free 
  • Form - Bush variety. fast growing, multi stemmed with an upright crown.

To order some hazel cultivars for delivery this winter contact us at balkanecologyproject@gmail.com

We can provide tracked and recorded delivery to anywhere in Europe


Keeping in Touch 


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While researching for this article a major resource was Volume 2 No 2, 3 and 4 of the excellent Agroforestry News, a quarterly publication from Martin Crawford - Director of Agroforestry Research Trust. I highly recommend subscription to this journal as essential reading for all who are interested in temperate tree crops and agroforestry.



Would you like to join us for our Regenerative Landscape Design course in Sep 2017?


We offer a range of plants and seeds for permaculture and forest gardens from our plant nursery including a new range of fruit and nut cultivars well suited to natural gardens. Delivery to all over Europe available from Nov - March 


References

Martin Crawford - Agroforestry News Volume 2  - Number 2, 3 &4
Hazel Ecology - http://www.iucnredlist.org/details/63521/0
Hazel Flowers - https://granthamecology.wordpress.com/2016/02/03/hazel-flowers/
History - http://www.geog.qmul.ac.uk/popweb/corylus/palaeo.htm
Cultivation - https://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/43804/em9072.pdf