A Giving Tree: The Mulberry
by Akiva Silver
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 summer. These trees are capable of holding unfathomable amounts of fruit every year, and that is one reason I call it a giving tree.
In some circles the mulbery 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 untouched is about 1,000 times more likely to fill with honeysuckle, European buckthorn, autumn olives, and multiflora rose than with mulberry trees.
Mulberries can be anywhere from 15 to 70 feet tall, and they are often just as wide. They have similar shapes and growth habits to box elders. There is a lot of diversity among the trees, both in form and fruit. There are two species that grow in the northeast, morus alba, the white mulberry which is native to Eurasia; and morus rubra, the red mulberry native to the Eastern U.S. These two species freely hybridize with each other in the wild. The names red and white are misleading, as the fruits of white mulberries can be white, red, black, or lavender. Red mulberries are anywhere from red to black.
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 species based on a couple of taste tests, excellent flavored trees are out there. The berries look like blackberries, but are often much sweeter. It is almost impossible to find a fruiting mulberry tree that is not covered in song birds. That is why they are sometimes called living bird feeders. Mulberries are true bird magnets, I have never seen a more reliable way to attract orioles.
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. There are no poisonous look alikes to the mulberry.
Mulberry trees can grow just about anywhere, and fast. They grow out of the cracks of sidewalks, in rich floodplains, vacant lots, and just about any open area. They can tolerate flooding, drought, and unreasonable pH levels at either end of the spectrum. They can be cut down again and again, and keep sprouting back. Milky sap oozes from their wounds, just like on a fig tree. The roots are bright orange, and their intensely rot resistant heart wood is bright yellow when first cut, darkening to a beautiful orange-brown with age. Mulberry wood is very hard and strong, with uses ranging from fence posts to cutting boards.
The leaves of mulberries can be all sorts of shapes, even on the same tree. They can have weird irregular lobes, or just be heart shaped. The bark of mulberry stems strips easily and is a very strong fiber with multiple survival uses.
The mulberry has been domesticated for thousands of years as a food for silk worms in China. This was attempted in America during the early colonial days up until the mid 1800s. The U.S. silk industry never amounted to anything primarily because of cheap overseas labor. One tragic legacy of this episode was the accidental introduction of the gypsy moth, which was being bred as a possible silk worm.
One ignored and more practical avenue for the mulberry to reach economic value is through poultry and livestock feed. Planting trees in, or on the edge of pasture could provide free feed for the entire summer.
If you want to grow mulberry trees for yourself or for wildlife, it’s important to know that some trees are male and some female. The female trees will bear fruit with very few seeds if no males are nearby, while the males will never make fruit. A seedling can take as long as 10 years to begin flowering, and then may change sex shortly afterwards. Grafted mulberries, or those grown from cuttings can begin fruiting within a year or two, because they are skipping the juvenile phase. These clones can be guaranteed to be female, but of course, they are evolutionary dead ends. The genetic diversity of seedlings is invaluable in a changing world. If you have the space, plant seedlings as well as one or a few named varieties.
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.