Black Mulberry Trees: Growing Tips for a Bountiful Harvest

Adding black mulberry trees to your landscape can greatly enhance its beauty as well as provide tasty fruit. To guarantee a plentiful supply of berries, it is essential to fertilize these trees and give them the necessary nourishment.

Fertilizing your tree is one of the best ways to grow a bountiful harvest, but knowing when and how to do it is vital to a guaranteed harvest. 

How fast do black mulberry trees grow? Black mulberry trees typically grow at a fast rate, averaging about 1 to 2 feet of growth per year. With the ideal climate, growing environment, and nutrients, they will reach their mature size of 30 to 40 feet tall and 45 feet wide in about 20 to 30 years. 

To ensure that your tree grows the best it can and will not suffer from stunted growth, the addition of fertilizer will provide the tree with everything it needs to thrive.

Continue reading for more specific information regarding its mature size, growing habits, and appearance.

You’ll also find details on its growing requirements, the best Hardiness Zones, and great companion plants to plant alongside it! 

Did you know that there are many different mulberry varieties and cultivars? Discover the most popular and their key features in my article Best Mulberry Tree Varieties today!

Black Mulberry Trees

Black mulberry trees grow like the other types of mulberry trees but have unique characteristics that are helpful to be aware of.

Botanical nameMorus nigra
Mature height30 to 40 feet tall
Mature width35 to 50 feet wide
Growth rateFast, 1 to 2 feet per year
Light preferencesFull sun or light shade 
Ideal soilNutrient-rich well-draining soil is ideal, but it is adaptable
Watering needs1 to 2 inches of water per week
FertilizationSpring after flowers bloom but before fruit begins to form
Years to bear fruit2 to 3
FlowersWhite or very light green
Fruit Dark purple to black, about 1 inch, sweet with a hint of tartness 
Harvest timeAugust through September 
Fall foliageYellow

Appearance

Commonly growing wider than tall, black mulberry trees take on a larger growth habit with age.

Large, glossy, green leaves that cover the delicious berries are bountiful in the summer, but the tree becomes bare in the winter season when dormant. 

Tree Shape

With a rounded canopy, the tree will grow long, strong branches that create a solidly round shape.

Sometimes the branches can get long, so trimming them shorter is helpful for harvesting the berries when they’re ripe. 

Leaves

Black mulberry leaves have a serrated edge and come to a point at the end. Commonly referred to as heart-shaped, they have a wider rounded base becoming skinnier toward the end and small teeth along the leaf margin. 

Bark

The bark of the tree is a classic silver and gray bark you’ll see on most woody species. With a medium depth of grooves, the bark adds texture to the landscape when there are no leaves present in the winter. 

Seasonal Beauty

During the spring, you’ll notice the barren branches begin to blossom with new green leaves. In late spring or early summer, the flowers begin to grow, eventually turning into the mulberries we all love.

When transitioning in autumn, the leaves will turn yellow before dropping to the ground for winter. 

Growth Rate & Mature Size

The growth rate is similar to the white mulberry and red mulberry varieties. Averaging growth of 1 to 2 feet per year, the trees reach mature size rather quickly.

While they grow quickly, they are considered hardy trees, surviving the winter easily. 

The average black mulberry tree will grow to be wider than tall, eventually reaching about 30 to 40 feet tall and 45 feet wide at maturity. 

Flowers

You’ll begin to notice the flower buds emerging in March and finally opening in April or May once the temperatures warm up.

The small, white, modified flowers are a sight to see! They grow small white styles, which is the female reproductive part that receives the pollen and fertilizes the berry. 

Black Mulberry Fruit

Black mulberry fruit is unique because it is technically many flowers all with the appearance of one, and one berry is made of 20 to 30 flowers!

Each small bump on the berry was once a flower, which is actually only shown by the female style. 

With newly planted trees, it will likely be several years before fruiting occurs.

After a few years, a young black mulberry tree produces about 12 pounds per season, but mature trees can produce up to 60 pounds yearly under ideal conditions.

The large and juicy fruit from these trees has a blend of sweetness and tartness similar to a blackberry that many people find delicious.

It is for this reason that Morus nigra is often believed to have the best fruiting characteristics and is regarded as the most flavorful of the mulberry species.

The sweet and juicy berries can be eaten right from the tree once they turn dark purple to black and are soft to the touch.

The ripe fruit can also be used to make jam or marmalade, pureed as a sauce, added to yogurt or a salad, made into various beverages, and more.

A person's hand full of ripe black mulberry fruits.

Fall Foliage

Because the black mulberry is a deciduous tree, the pretty green leaves will not remain on the tree all year.

The leaves will transition from a lush green color to a vibrant yellow in the fall before they drop off the dormant trees in early winter, so enjoy this unique splash of color while it lasts!

Life Expectancy

While averaging a lifespan of about 25 to 50 years in landscapes, the mulberry tree has been known to last more than 75 years in the wild.

Black Mulberry Tree Growing Conditions

Mulberry trees are widely adapted and are cold-hardy, so they don’t require much special treatment.

They will do best in areas of full sun and when given protection from frost pockets since they will lose their fruit if a late frost hits the area. Overall, they only need the basics — sunlight, water, and cold and warm seasons. 

Grow Zones and Hardiness

The best USDA Zones to grow a mulberry tree are Zones 4 through 8. They prefer full sun but can handle partial shade.

They overwinter well, and they are only adversely affected by high temperatures when in direct sun.

They will do well in higher USDA Zones and will thrive as long as they have mild protection. 

Sun Requirements

Full sun or partial shade is best, so aim to give the tree 6 to 8 hours of sun per day. If planting in a higher Grow Zone, aim for the same amount of hours but with some shade or in filtered light. 

Soil Preferences

Mulberry trees can adapt to various soil conditions, but they do best in well-draining loamy soil. They will grow well in slightly acidic soil in the range of 5.5 to 6.5 pH.

The more fertile the soil, the better the berries will grow!

If you plan to plant your mulberry tree in an area with little soil fertility, either fertilize at planting time or amend the planting hole beforehand with organic materials for the best results. 

Black Mulberry Tree Maintenance and Care

Mulberry trees grow regularly in the wild as “weed trees,” so growing them in a landscape is basically just as easy as growing weeds!

See more details below for tips and tricks to ensure your tree grows for years to come. 

Watering

During the growing season, try to give your mulberry tree about 2 inches of water per week.

When the tree is bearing fruit, you’ll want to ensure it receives at least 2 inches of water per week or more to grow the plumpest, juiciest berries.

Fertilization

Mulberry trees will commonly grow bountiful fruit on their own but will grow even more large black berries when fertilized.

To get the highest quality mulberry fruit, fertilize your tree right after the flowers bloom. This way the tree will have all the nutrients it needs to produce sweet, large berries. 

Be sure to not fertilize the tree before the blooms open or once the fruit is present on the tree. Fertilizing before the flowers open might cause them not to open or cause the tree to revert to growing leaves instead. 

Pruning

Pruning your mulberry tree is a great way to increase branches for berries to grow on or to maintain the shape you desire. 

Every time you prune a branch, secondary branches will grow, doubling the number of fruiting branches. It is also always recommended to follow the pruning rule of the “Three Ds.”

Dead, Diseased, or Dying branches should be pruned away to help keep the tree healthy and to stop diseases from spreading. 

Harvesting

Since this is the black variety of mulberry, you’ll want to wait until the berries are at least 85% black before picking them.

If the berry resists being picked, you’ll want to let it ripen longer on the tree. If you pick them too early, they will never reach their full potential for sweetness. 

Pests & Diseases 

The worst pests you’ll encounter are animals and birds that want to eat the delicious berries!

Preventative measures are best because stopping the pests after the fact is where issues will arise, and it is much more difficult to correct than to prevent in these cases.

See the list below of common pests and diseases that may affect your mulberry tree.

Common Diseases

  • Bacterial canker
  • Armillaria root rot
  • Bacterial blight
  • Cotton root rot
  • False mildew 
  • Powdery mildew

Common Pests

  • Japanese beetles 
  • Thrips
  • Scale
  • Grasshoppers
  • Spider mites

Weekly sprays of neem oil (find it here) help to prevent these bugs from taking hold during the fruiting season.

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Landscape Uses & Wildlife Value

The black mulberry species can be shaped to be a lovely ornamental tree with the sweet berries being an added bonus.

Use them as stand-alone specimen trees, in areas where more finicky plants will not grow, or even in rows as shade trees. 

When the berries ripen, you’ll notice wildlife of all kinds; they love the berries just as much as we do! Songbirds will come to enjoy the berries and treat you with a song in return. 

Like the native red mulberry, black mulberries are not considered invasive, but birds may occasionally distribute seeds, so a few volunteer trees might show up from time to time.

Companion Plants

Take advantage of the space under your mulberry tree to maximize what you can grow in your garden!

Low-growing species like chives, nasturtiums, marigolds, garlic, and lemon balm all help attract pollinators and other beneficial insects! Plus, you get to add color and diversity to your landscape. 

Where To Buy

Buy your mulberry tree at any local nursery. They’re commonly carried since they are so easy to grow and they are a favorite for many gardeners.

Check out some online nurseries as well! You may find more varieties to choose from and can have a tree shipped directly to your door. I recommend and frequently use the following online sellers:

Closing Thoughts 

A mulberry tree is really a dual-purpose tree! It’s a lovely landscaping shade tree that will also grow a delicious summer treat.

Many times, you can plant it and walk away as a mulberry tree is easy to grow and keeps giving for seasons to come. With a little TLC, you’ll be rewarded even more bountifully than letting it grow on its own!

Ready to discover other delicious mulberry options? Learn about these varieties next: