Imagine a large spreading tree that has delicious fruit hanging from every leaf node. The fruit are various colors and resemble blackberries. There appear to be millions of them on a single tree. Every day all summer long, new berries ripen. That is the mulberry. I believe it might be the most generous tree on Earth. There are trees like the apple or the oak that will drop a huge crop of food, but a good mulberry tree will have a continuously unfolding enormous crop for months on end.
Overwhelming abundance.
While some adults hate mulberry trees, virtually every songbird and kid loves them. They are such generous trees that in tropical regions, mulberries are capable of bearing fruit 12 months of the year. Here in the Northeast, we can find individual trees that will ripen their delicious berries from June until the end of September. These trees are capable of holding unfathomable amounts of fruit every year, and that is one reason I call the mulberry a giving tree.
In some circles the mulberry has a reputation for being invasive. This is an unfortunate accusation, particularly here in New York State. White mulberries have been here for centuries, and red mulberries are native. They have had ample time to become invasive. However, I have never seen more than a few scattered trees in one place. In the Northeast they do not form dense thickets like Norway maples or ailanthus trees. A field left unmowed is about a million times more likely to fill with honeysuckle, European buckthorn, autumn olive, and multiflora rose than with mulberry trees.
Mulberries can be anywhere from 6 to 70 feet tall, and they are often just as wide as they are tall. In general, they have similar shapes and growth habits to box elders. The berries vary in taste as much as in color. Some mulberries are just not that good, while others are outstanding. Don’t judge the entire genus based on a couple of taste tests. Excellent-flavored trees are out there. I have found several great ones in the wild, including one individual that is better than any cultivar. Mulberries look like blackberries, but are often much sweeter. It is almost impossible to find a fruiting mulberry tree that is not covered in songbirds. They are living bird feeders and true bird magnets; I have never seen a more reliable way to attract orioles than to have a fruiting mulberry around. If mulberries are near waterways, there will always be ducks and geese underneath. They also attract turkeys, as well as squirrels, chipmunks, and just about every other mammal.
These spreading trees often have low drooping branches for easy picking. The dark fruits stain fingers and tongues, and purple bird poop stains cars and sidewalks.
Mulberry trees can grow just about anywhere, and fast. They grow out of the cracks of sidewalks as well as in rich floodplains, vacant lots, and just about any open area. They will germinate in the shade and sometimes fruit there. They can tolerate flooding, drought, and unreasonable pH levels at either end of the spectrum. Mulberries grow fine under the full shade of black walnuts and still produce decent crops. They are the epitome of a resilient ally, a tree that will provide despite the worst hardships and setbacks.
There are no poisonous look-alikes to the mulberry. Almost every city in the United States has some growing wild.
Species
Four species of mulberry can be found in North America. They are confusingly named by colors that seem to have little significance.
White Mulberry (Morus alba)
The white mulberry is native to Eurasia. It produces berries that can be white, but are more often red, black, purple, or lavender. The leaves are the primary food source for silkworms in Asia, and the tree has been domesticated for thousands of years in China. This was attempted in America during the early colonial days up until the mid-1800s. The US silk industry never amounted to anything, primarily because of cheaper overseas labor. One tragic legacy of this episode, though, was the accidental introduction of the gypsy moth, which was being bred as a possible silkworm.
The silk industry may never have taken off in the US, but the trees did. Morus alba has been very successful at naturalizing itself across the country. It is now found growing wild in all of the Lower 48 states.
Morus alba is a very tough tree. It will be quite happy growing out of a sidewalk crack or really almost anywhere besides wetlands. It is extremely drought-tolerant and is cold-hardy to zone 4, with a few populations surviving into zone 3.
Morus alba is considered a threat by many native-plant enthusiasts, not because it crowds out the native mulberry, but because it hybridizes with native mulberries readily. M. alba does extremely well in urban environments, and that is where you are most likely to find it growing. Some of its most common sites are along highways, in vacant lots, and up against buildings.
The leaves of white mulberries can be all sorts of shapes, even on the same tree. They can have weird irregular lobes, or just be heart-shaped.
There are many forms of Morus alba, including weeping, contorted, dwarf, and giants reaching well over 50 feet tall. Countless cultivars of M. alba and its hybrids have been selected for fruit and form. Tragically, many cultivars are fruitless male trees. Sometimes I just don’t understand people. Why would anyone want to select for a fruitless mulberry tree? That’s like having a car that doesn’t drive or a pen that doesn’t write.
Red Mulberry (Morus rubra)
This tree is native to the eastern half of the US. It has become rare due in large part to white mulberries crossing with it. Misidentification of Morus rubra is rampant, and virtually all nurseries and botanical gardens that claim to have Morus rubra actually have M. alba or a hybrid. For a detailed discussion of this catastrophe, check out Incredible Wild Edibles by Sam Thayer. His chapter on mulberries does an excellent job of explaining how M. rubra has become virtually a lost species through misidentification.
Morus rubra makes red- to black-colored berries and can grow up to 70 feet tall. After learning from Sam Thayer, I believe I have only actually found one M. rubra tree in my life. I previously thought I had seen hundreds. The leaves are unlobed on mature specimens and resemble basswood. Again, check out Sam’s book if you really want to know about properly identifying this tree. This mistake permeates the horticultural and restoration industries.1
Black Mulberry (Morus nigra)
This is the mulberry tree that is most cultivated around the world. Unfortunately for me, it is not very cold-hardy. Zone 7 defines the limits of its northern range. Black mulberries are considered the best-tasting fruits and are the largest. Some cultivars have berries that are 4 inches long! They have been cultivated in Central Asia for centuries, where they are used for juice and dried berries. Black mulberries are considered a staple crop in parts of Afghanistan and Pakistan.
Texas Mulberry (Morus microphylla)
This small tree is also known as the little leaf mulberry. Its native range is in the western two-thirds of Texas. It bears red to black berries.
Wood
Mulberries can be cut down again and again, and keep sprouting back. They are one of the most resilient species for coppicing. Milky sap oozes from their wounds, just like on a fig tree. The roots are bright orange, and their rot-resistant heartwood is bright yellow when first cut, darkening to a beautiful orange-brown with age. I still remember the first time I saw a mulberry tree cut when I worked for a tree service. Ribbons of yellow sawdust as bright as a highlighter came flying out of the trunk. I brought some of the wood home and made several spoons and cutting boards. As the wood was exposed to light over the coming months, it turned to a deep orange-brown with a beautiful finish.
Mulberry wood is very hard and strong, with uses ranging from fence posts to cutting boards. It is fairly rot-resistant and extremely beautiful. Mulberry is hard and dense and makes great firewood, too.
Mulberry wood is not recognized for its economic value, but its density and rich color make it a gift to specialty woodworkers.
The bark of mulberry stems strips easily. It is a very strong fiber with multiple survival uses. Most tree barks will not strip unless the sap is flowing in spring or early summer, but mulberry offers its fibers any time of year. It is strong enough to use for bow drill fire making without twisting into cordage, or as an emergency dog leash.
Propagation
Mulberries have been one of my favorite trees for a long time. I have always been so amazed at how much fruit they are capable of producing. I love that the fruit can leave a purple stain on fingers, mouths, and cars; that it can feed a million birds and still leave huge amounts of delicious berries for the rest of us. After a lifetime of generously dropping copious amounts of fruit from the sky, a mulberry tree will leave behind a trunk of beautiful rot-resistant wood. I am intrigued by the commercial possibilities of this tree, from dried fruit to jam to poultry feed. And I am totally amazed that mulberry trees are not widely available at nurseries along with apples and peaches. When I first tried to buy a mulberry tree, I could not find one anywhere locally, so I decided to grow my own. That was in 2007, and I have grown thousands since. Here are some of the lessons I have learned along the way to successfully propagate mulberries. I am not done discovering the nuances of propagating mulberries.
Cloning Versus Seed
Mulberry trees are dioecious, meaning that some trees are male and some female. If a female tree is growing with no males nearby, the tree will make lots of fruit with either no seeds or unviable seeds, while a male tree will never fruit. Growing trees from seed means that you don’t know what sex the seedlings will be until they flower. A seedling mulberry often takes from 5 to 10 years to begin flowering. A grafted mulberry will begin flowering and fruiting its first or second year because it skips the juvenile phase by using the mature wood of an older tree.
If you grow a fruit from seed, it will produce a tree different from its parent, just like every kid is different from their parent. Some mulberry trees’ fruit taste much better than the average wild tree. In order to get another tree with the same fruit, it would need to be cloned. It could be grown from cuttings, grafted, or layered. If it was grown from seed, it might be a male or a female and it might make fruit very different from its parent.
The benefits of seedlings are that they are easy to propagate in large numbers and they increase the genetic diversity of the species, allowing mulberries to continue evolving. Clones, while rewarding to grow, are an evolutionary dead end. Seedlings are also the only way to discover new varieties. Seedlings are highly suitable trees for wildlife and livestock, and they often produce decent fruit. The first three seedlings I grew to fruiting age began bearing at age six. Each tree made hundreds of berries that year. One tree had red berries, one black, and one white. They all tasted good. It was a very satisfying experience to pick them with my kids that summer. I believe there is tremendous value on either side of this coin. Growing mulberries from seed and growing them by cloning are both worthwhile pursuits and a great use of time.
Cuttings
Some varieties of mulberry are much easier to root than others. I have been able to root hardwood cuttings when they are gathered in late winter and placed in trays with bottom heat, keeping the tops cool. I use a very light mix that is about 70 percent sand and 30 percent compost/soil, or 100 percent sand. Hardwood cuttings have rooted at a low percentage for me. Some batches of cuttings treated in this way had around 25 percent success rate, while others were zero.
Softwood cuttings have been more successful for me since I built an intermittent mist system. The cuttings are placed in beds of sand that have a heating cable underneath. A fine mist is sprayed on their tops every 10 minutes for a duration of 10 seconds. I take the cuttings when they are most actively growing during summer. I cut them into pieces about 3 or 4 inches in length. I cut most of the leaf off, just leaving a small portion attached to the cutting. Under these conditions I’ve had certain varieties root in as little as two weeks, but some others never seem to root. The biggest challenge to softwood cuttings is overwintering the tiny rooted plants. Overwintering rooted hardwood cuttings is easier because the plants are so much larger and stronger.
Many southern growers report that rooting mulberries is as easy as stabbing a branch into the ground. I believe the reason for this is that certain varieties are much easier to root than others. I have not yet found a northern variety that roots with such ease.
Grafting
Grafting is one method that works for cloning superior female varieties. Mulberries are a little more difficult to graft than apples or pears, but certainly doable. Bench grafting mulberries in May has worked somewhat well for me. I have had about 65 percent take. The real struggle has been overwintering grafted mulberries.
The graft unions on mulberry are tender. They need to be protected for their first year or two in my climate (zone 5). Burying the graft union is sometimes enough, but often not. The most reliable way to overwinter them is to place them in an unheated basement or attached garage and then plant out in the spring after danger of frost has passed.
If you have never grafted before, I think it is a good idea to practice on something else. You can make grafting cuts on any freshly growing shoots of a nearby tree or bush. Save your valuable plant material for when you feel confident. Mulberry bark shreds and peels so easily that you need a very sharp knife and a sure hand.
Layering
I am currently experimenting with layering mulberries in stool beds. So far it appears they need two growing seasons to root. I’m just getting started with this method and am excited about its possibilities. Layering offers strong plants on their own roots and can give difficult-to-root varieties plenty of time.
Mulberry seedlings are easy to start in great numbers, but watch out for slugs!
Seed
Growing mulberries from seed has been very reliable for me. It is easy to start thousands of trees in a few minutes if certain things are given attention. The first thing to be aware of is the tree that you gather seed from. Some fruit-bearing trees do not have a male tree nearby, so any seed you find in the fruit is likely to be sterile. It is best to find a fruiting mulberry that has lots of close neighbors. This will bring seed viability to very high levels.
Seed can be cleaned from the fruit and dried. I obliterate the fruit in a bucket of water with a paint mixer. I then pour off the excess water, taking care not to dump the seeds. Add more water, stir it, dump water, add water, stir, dump, add water, stir, dump … Eventually all the fruit pulp will have floated away and you will be left with a considerable amount of seed in the bottom. This method of cleaning seed is known as decanting, and it works well for separating many types of seeds from fleshy fruit.
Mulberry seeds do not require stratification or treatment of any kind. I store them dry as you would vegetable seeds. I lightly rake them into the soil so that they are at or just below the surface. They usually sprout within a couple of weeks.
One catastrophe to avoid when growing seed is slugs. They can easily wipe out an entire tray in a single night. Mulching with fresh sawdust has helped me a lot with this. There are many people out there with lots of strategies for dealing with slugs. Whatever you do, just beware of them. I cannot overemphasize how quickly they can devastate a thousand mulberry sprouts.
Two-year-old mulberry seedlings dug up from the nursery.
Another hazard for baby mulberries is frost. I wait until danger of frost has passed before sowing seeds. If a frost is coming, be sure to protect them or they will be killed by the freezing temperatures.
Mulberry seedlings often grow very fast. It is almost impossible to stay ahead of them by increasing pot sizes. Trees grown bareroot always have better root systems and are much bigger. One to 3 feet is a typical size for first-year mulberries; second-year trees can be 6 feet with beefy roots and thick stems. Potted trees rarely grow more than 10 inches their first year and are usually horribly root-bound.
Growing your own mulberries from seed or through cloning is very satisfying and rewarding. Trees can begin bearing fruit at a young age and continue to do so for the rest of your life. Mulberries are a gift to yourself, your kids and grandkids, songbirds, wildlife, livestock, and the world in general. There really are very few trees that can match the generosity of a mulberry. So plant a lot; the world is only better for their presence.
This guy doesn’t mind getting messy gathering mulberries.
Harvesting and Processing Mulberries
There are trees from which the fruit needs to be picked and there are individuals whose fruit falls freely. The free-falling trees are much easier to harvest large quantities from. Place a clean sheet or a tarp under the tree, climb, and shake. It’s amazing how fast you can fill a bucket using this method. It takes a minute to pick out leaves and twigs from the tarp, but it’s still far faster than picking individual berries by hand.
The berries can be made into juice or jam, or dried. If you’re making jam, then put them in a food processor to help make the short attached stems unnoticeable.
Dried mulberries are a great addition to cereal or trail mix, or just eaten by themselves. You can dry the berries whole in any dehydrator. I love chewing on them in the winter.
Reportedly, eating unripe mulberries can lead to an interesting experience involving hallucinations. I tried this several times with zero effects. I’m not sure where this information comes from, but I’d love to hear from someone who has personally experienced tripping on unripe mulberries.
Varieties
There are many varieties of mulberries cultivated in the US and around the world. Here are a handful of them.
Weeping: A few different cultivars of mulberry have a weeping form. Many cities plant weeping mulberries that are fruitless male clones. Fortunately, there are also weeping female mulberries that bear small, tasty black berries. Weeping mulberries can be staked to their desired height and then allowed to drape down. I can’t think of a more awesome landscape feature for a kid than a tent of fruiting mulberry to crawl into.
Dwarf Giraldi: This variety only reaches 6 feet high at maturity. It can be grown in a pot on a patio or balcony. Bears good black fruit.
Kokuso: Morus alba. An excellent variety from Korea, Kokuso bears delicious large dark purple berries that ripen over a short window (for mulberry), about three weeks in early summer. The berries fall freely from the tree with a light shake, making collection fast and easy. Kokuso is also very hardy, reportedly to zone 3. The leaves on this tree are enormous, about twice as big as a normal mulberry. The growth habit of this tree is somewhat shorter than seedlings. Kokuso has good potential to contribute to a commercial mulberry orchard because the harvest window is condensed, and the berries are of a high quality.
Illinois Everbearing: Hybrid of Morus alba and M. rubra. This hardy tree has a very long ripening window, as berries turn dark and sweet all summer long. The fruits are big and tasty. They need to be picked, as they cling to stems strongly.
Pakistani: Morus nigra. Hardy to zone 7. Pakistani bears a huge tasty fruit that can be 4 inches long.
Everloving: Possibly a hybrid of Morus rubra and M. alba. I discovered this tree growing wild in Ithaca, New York. It is hardy to at least –25°F (–32°C). The black berries have the best mulberry flavor I’ve tasted by far. Fruit begins ripening in late June and continues into September. It bears consistent crops from year to year, and the fruits shake down easily. The berries are not as big as Illinois Everbearing, but the flavor and ease of harvest more than make up for that. I have been observing this tree closely for the last nine years and I believe it is worthy of being widely planted in landscapes and orchards. To date, it is my favorite variety.
White: There are many varieties and wild trees with white or white/lavender-colored fruit. The ones I have tasted are sweet with little other flavor. I don’t enjoy eating white mulberries nearly as much as most dark ones. A good mulberry will not only be sweet but also have a complex flavor. White mulberries are often planted because the fruit will not stain fingers or sidewalks. One thing I do like about white mulberries is that they are very good dried.
Commercial Possibilities
I believe the mulberry holds serious possibilities for the entrepreneur. There are numerous cultivars available, and wild trees are plentiful for people looking to sell fruit raw or processed. Some of the biggest drawbacks are stems and a short shelf life. I have yet to find a tree that drops the berries without a stem attached. The stem doesn’t bother me, but it might be a tough sell to the public. The shelf life of fresh fruit is pretty short, making transportation difficult.
As with most fruits and nuts, I think these deficiencies in mulberry fruit can be overcome through processing and creativity.
Mulberry juice, jam, and dried berries are already commercially available. I cannot even imagine the juice yield per acre in a mulberry orchard. It must be enormous.
U-pick mulberry would surely attract attention. Harvesting mulberries is great fun for kids and families.
One ignored but practical avenue for the mulberry is poultry and livestock feed. Trees planted in or on the edge of pasture will supplement feed for the entire summer when they drop their fruit. The leaves are also excellent feed for cattle, sheep, and goats.
Of all the businesses I have dreamed of over the years, I believe growing mulberries may be one of the best. There is such a mystique around this tree. It is amazing to see people’s reactions when I talk about mulberries. Sometimes people are quite turned off to anything mulberry, but more often their eyes light up. I know that a U-pick mulberry orchard would be worthy of a festival drawing folks in from out of state. You just cannot overestimate the power of a tree that holds childhood memories for so many people.
If ever there was a tree to love—a tree so generous and fun that every neighborhood, chicken yard, hedgerow, animal pasture, and old field needs at least one—it is the mulberry.