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 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.

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.

But first I want to take this opportunity to let you know that we’ve just launched a brand new Regenerative Landscape Design — Online Interactive Course — How to Design, Build and Manage Polycultures for Landscapes, Gardens, and Farms.

You can find out more about the course here to see if it tickles your fancy 🙂 and if you’d like to take part we are currently offering a 20% discount to the first 10 people to enroll. Register here with promo code 1st102020 to take advantage of this offer.

We are looking forward to providing you with this unique online learning experience — as far as we know the very first of its kind! If you are looking for reasons why you should do this course and whether this course is suitable for you, take a look here where we lay it all out.

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.

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.

A parable on the perils of tardiness.

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

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.

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.

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.

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.

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.

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.

All fresh leaves are fine to use for the tea. You can simply run your hand down a branch and strip all the leaves, they come off really easily. The leaves can be dried whole or cut into strips. I dried some cut leaves on our kitchen table by a sunny window and they were dry within a day and half.

Simply crumble a few leaves into a cup and poor on hot water and you have a very decent tasting cuppa. I’ll see about those grey hairs.

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.

If you have a tree that you would like some work carried out on and you are based in the US you can find your local expert on The Local Tree Experts.

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

You can find a detailed write up of this polyculture and many more in our Regenerative Landscape Design — Online Interactive Course

Regenerative Landscape Design — Online Interactive Course — How to Design, Build and Manage Polycultures for Landscapes, Gardens and Farms

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. #KhabarLive #hydnews