Complete Guide For Hackberry Tree – What You Need To Know

Hackberry is a deciduous hardwood tree native to North America. Scientifically known as Celtis occidentalis, it will grow 50-80’ tall in full sun and well draining soil.  Providing year round interest, Hackberry has a handsome oval to vase like crown and nice foliage as well as providing fruits that feed birds well into Winter.

In this article:

• Hackberry Tree Facts / Quick Reference
• Pros and cons of the Hackberry Tree
• How to Identify Hackberry Trees
• How to Grow and Care for Hackberry Trees
  • How to Grow Hackberry from Seed
• What Wildlife, Pests, and Diseases effect Hackberry Trees
• Where to buy Hackberry Trees
• Uses of Hackberry Trees
• Final Thoughts

Hackberry Tree Facts / Quick Reference

A medium to fast growing tree, Hackberry can grow up to 2’ per year in optimum growing conditions.  With it’s trunk wrapped in some of the most interesting bark in North America, it can be eye catching to anyone passing by.  Easy to grow the nuts from seed, the outer layer of the fruit is actually edible and tastes very similar to a fig newton. 

Frequently used as a street tree an along Highways, Hackberry is extremely tough and adaptable. Although not commonly used in residential landscaping, it should be considered more often. Hackberry looks just as good as the commonly used invasive Bradford Pear tree, and Hackberry actually contributes to the pollinator community by hosting multiple species of caterpillar.

The most common way to propagate Hackberry is via seed germination. However, it is possible to root cuttings taken from new growth on trees as well.

Hackberry versus Sugarberry

A closely related cousin to Hackberry (Celtis occidentalis) is known as Sugarberry (Celtis laevigata). Their native ranges overlap, but Sugarberry is more present in the Southern States while Hackberry is in the North.

These species are very difficult to differentiate, and the primary difference is the location they grow, with Northern Hackberry being tolerant of alkaline soils and growing in uplands, whereas Sugarberry grows more in bottom lands. [1][2]

Quick Reference Table For Hackberry

Common Name	Hackberry, Beaverwood, Common Hackberry, American Hackberry, Nettletree, Northern Hackberry, Sugarberry
Scientific name	Celtis occidentalis
Bloom Time	Spring, 1-2 weeks
Bloom Characteristics	Small green flowers 1/4″ diameter. Flowers are inconspicuous and not showy.
Height	60′-80′ (18m – 24m)
Spacing/Spread	40′-50′ (12-18 m)
Lifespan	150-200 years
Growth Rate	1-2′ per year (30-60 cm)
Light Requirements	Full sun to partial shade
Soil Types	Well drained soil, but adaptable from sandy-loam to clay-loam
Moisture	Moist to medium-moisture. Can tolerate intermittent or occasional flooding.
Maintenance	Prune dead/dying limbs in Fall after insects are dormant.
Typical Use	Shade tree, edge of woods.
Fauna Associations	Numerous butterflies, moths, and other insects are hosted. Birds/mammals eat fruits.
Sowing Depth	1/4-3/8″ deep
Stratification	90 Days
Native Range	Eastern North America
Growing Zones	USDA Zones 3-8

Native Range

The native range of the Hackberry Tree is from Oklahoma East to North Carolina. Then North to North Dakota, New Hampshire, and all areas in between. It also is native to Southern Ontario. There are also isolated pockets noted in Mississippi, Alabama, Georgia, and North Texas. [1]

Regardless of it’s native range, it is possible to grow Hackberry in almost the entire United States. It is hardy from zones 3-9, meaning that just about anywhere in the continental United States could grow Hackberry except for Southern Florida.

Pros and cons of Hackberry Tree

Pros

Fast growing

Hackberries can grow up to two feet per year in optimum growing conditions, making it one of the fastest growing North American hardwood trees. If you are looking to establish some native trees quickly, a Hackberry can make a good choice.

Tough

The Hackberry Tree has a reputation as highly adaptable and tough. It has earned this by being able to grow in a variety of environments. Once established, the Hackberry is wind, drought, road salt, and pollution tolerant. It can be used in reclamation sites and will tolerate alkaline soil.

Wildlife

Hosting numerous butterfly and moth caterpillars, the Hackberry Tree is valuable for wildlife. In addition to supporting pollinators, the fruit it produces feed birds all Winter long as well as some mammals.

Beauty

Grown in the open the Hackberry will generally grow straight and tall, frequently reaching 60-90′ (20-30 m). It can make a handsome addition to any landscape.

Really cool bark

The bark of the Hackberry Tree is arguably some of the most interesting to look at. The tall narrow vertical ridges make it identifiable from a distance. No other tree bark looks anything like it.

Cons

Weak limbs

During the first 10-20 years of a Hackberry Tree’s life it will need to be carefully pruned to avoid the formation of weak crotched limbs. If this does not happen, then certain limbs may be prone to breaking off. Remember, a narrow v-shaped crotch leads to weak branch collaring, which makes the limbs prone to breaking off. [2]

Leaf diseases

Hackberry Trees can be victims of numerous leaf spot fungi. While this doesn’t really harm the tree per se, it does take away from an otherwise stately appearance. [1][2]

How To Identify A Hackberry Tree

Mature trees can reach heights of 80′ tall with an ovoid crown.

Trunk/Bark

Mature Hackberry trunks typically reach 18-24″ diameter. Most of the girth is added after 20 years of age. In the Westernmost part of the range old trees of over 100′ tall and 48″ d.b.h. have been recorded.

The Hackberry boasts some of the most unique bark one may encounter in North America. It is light brown to gray in color and smooth when young, and will have white lenticels. At maturity, tall ridges or bumps form, giving it an almost stucco or ‘popcorn ceiling’ look.

Once you’ve seen the bark, you will never have difficulty identifying a mature Hackberry tree. The bark is interesting by itself, perhaps second only to Shagbark Hickory trees.

Leaf

Leaves of the Hackberry Tree are alternate on the limbs, 2-5″ long by 1-3″ wide, and narrow to broad ovate in shape with serrated margins. The individual leaf shape of Hackberry is often asymmetrical, similar to American Elm. In Autumn, Hackberry leaves will turn a golden yellow color. [2]

The leaves of Hackberry trees closely resemble Elm leaves. And I could see misidentification occurring if only the leaves were examined. However, the bark is the true ‘tell-tale’ marker of a Hackberry.

Flower

In Spring small green to yellow flowers that are roughly 1/4″ diameter (6 mm) will bloom. The flowers are very inconspicuous and are wind pollinated.

Fruit

Flowers are replaced by black to dark purple drupes in early Summer, maturing into small fruits by late Summer / Fall. The reddish-brown mature fruit are approximately 1/2″ diameter and round, and will contain a single 1/4″ diameter seed. [2]

Are Hackberry fruits edible?

The outer flesh of Hackberry fruit/nuts are edible. I find the fruit to taste similar to Fig Newtons. But, as you can see from the dimensions…there isn’t much flesh on a fruit. Nonetheless were you in a survival situation Hackberries would provide some calories. Native Americans did crush berries/nuts up and grind them into a paste, which would provide more sustinence.

Root

The root system of Hackberry Trees is deep and strong. Roots commonly reach 10-20′ deep (3-6 m) and 40′ wide (12m). It is however adaptive (like most trees) in that when faced with tough clay soil, the roots will only penetrate 4-5′ deep. [1]

How to Grow and Care for a Hackberry Tree

Sunlight Requirements

Hackberry will prefer full sun, which is at least 6 hours of direct sunlight per day. It can tolerate partial shade, but will not grow as fast. Also, if it receives irregular sunlight it may not grow straight. [2]

Young seedlings are more tolerant of shade in the understory. However, they eventually will need sunlight. In a forest situation for a young sapling to survive to maturity, this often comes when other older trees fall down or die.

Moisture Requirements

Hackberry Trees grow best in either moist or medium-moist soils that drain well. It can grow near water and tolerate occasional flooding. However, prolonged exposure to water or poor draining soil may cause root rot, which is fatal to the tree. [1]

Soil Requirements

For soil, Hackberries will grow best in loamy soil rich in organic matter that drains well. It is however highly adaptable and can grow in sandy-loam to clay-loam. It has been noted as growing in hard clays of North Dakota as well.

For pH, Hackberry is tolerant of a wide variety of levels. It can grow in acidic soils or heavily alkaline soils. For instance it has been used as a street tree in Texas when soil pH is regularly above 8. [2]

Pruning

Hackberry Trees should have dead/dying limbs pruned when noticed. But the best time to prune a Hackberry tree is just before Winter when insects are inactive and the leaves have fallen. This allows the tree to scab/heal itself without having insects transmit any diseases to fresh cuts.

And remember – focus on pruning limbs on narrow v-shaped crotches! Those limbs will form weak branches as the tree matures. You want a single trunk tree, not multi-trunk. Don’t worry about lateral limbs as long as they are closer to perpendicular to the trunk. Taking out too many of those could result in sunscald.

Maintenance

Outside of occasional pruning, Hackberry trees should not require any significant maintenance. The fruits/nuts generally stay attached to the tree until eaten by birds or squirrels. What fruit does fall will only temporarily stain sidewalks. So it isn’t necessarily as messy as a Black Walnut or some Oaks.

How to grow Hackberry from seed

Growing Hackberry from seed is fairly straight forward as far as sowing goes. You will want to gather ripe fruits in late Summer to early Fall when they start to turn a reddish purple color. Determine how many trees you would like to grow, then gather about three times as much seed.

To prepare the seed, simply remove the thin coat of flesh from the fruit, revealing a nut. You should be able to scrape it away with your finger nail. It will be a somewhat messy job, so have a paper towel handy. Pat the seed dry and then store in the fridge in a zip-lock bag until you sow or cold stratify the seed.

Hackberry seeds will need to undergo 90 days cold stratification to break dormancy. [3] So you should either cold stratify the seed in moist sand in a zip-lock bag in the fridge, or Winter Sow the seed. If you cold stratify the seed in the fridge, then you can plant the seed once Spring arrives. *Note – Winter Sowing seed is preferable to stratifying in the fridge.

How to plant Hackberry seed

The following assumes you have either cold stratified or are Winter Sowing the seed.

1. Fill a suitable container with moist potting soil. If you grab a handful and squeeze, a few drops of water should fall out.
2. Soak the seeds overnight in water at room temperature
3. Plant the Hackberry nut 1/4″-3/8″ deep (6-9 mm). Pat the soil firm.
4. Place the container outside or in an unheated garage or shed.
5. Monitor the container periodically, making sure it doesn’t dry out.
6. Seeds should germinate once temperatures warm up in Spring.

I grew this tree on a whim. While foraging for Hickory nuts I came across several mature Hackberries that were loaded with fruit. So I gathered up 20-30 berries and took them home. I planted 15 seeds and had 10 germinate. And for my container? I just used a regular pot and left it completely exposed.

So compared to my normal methods, I was quite sloppy. But nonetheless I think 10/15 germination was ok for not doing much research!

What Wildlife, Pests, and Diseases Effect Hackberry Trees

Pollinators

The Hackberry Tree hosts numerous butterflies and moths. Some examples include the Eastern Comma, Empress Leilia, Hackberry Butterfly, Hackberry Emperor, Mourning cloak, Snout Butterfly, and Tawny Emperor. [4][5]

Birds

The Hackberry is a great tree for attracting birds. The fruit is eaten by numerous birds such as Cedar Waxwing, Grouse, Yellow-bellied Sapsuckers, Mockingbirds, Robins, and other fruit-eating birds. It can even attract Turkey, Quail, and other game birds who also enjoy the fruit/nuts of the Hackberry Tree. [1][2]

Mammals

The fruit/nut of the Hackberry contain sugar which is make it attractive to a variety of mammals. In addition to birds, chipmunks, mice, raccoons, squirrels, and other mammals will also consume the fruit when available. [1][6]

Pests

Wood boring beetle

A damaging beetle known as the ‘Hackberry Engraver’, Scolytus muticus, may attack living limbs and sapwood, potentially killing the tree. More often it only eats dead/dying limbs though.

Galls

There are four species of gall-producing insects that are hosted on Hackberry. The formation is eventually known as ‘nipple-gall’. The damage is only cosmetic, but the adult insects hide in the rough bark or in leaf-litter throughout the Winter and then lay eggs on leaves in Spring, which produces the galls. [7]

Diseases

Witches Broom

Hackberry is suceptible to Witches Broom fungi, which will cause rosette-like branch tips. These are caused by a gall mite or a powdery mildew. If you notice strange clusters of branch tips appearing on your tree, contact an arborist for a formal diagnosis and treatment.

Leaf-spot fungus

There are several leaf-spot fungi that can infest Hackberry Trees. Most of these only cause cosmetic damage.

Where to buy Hackberry Trees

Hackberry trees are available at tree nurseries. You can also purchase them as bareroots from companies such as coldstreamfarm.net. There are also some varieties and cultivars around that have been selected for insect or disease resistance.

Varieties of Hackberry Trees

Some varieties and cultivars of Hackberry Trees that are available:

• Prairie Pride – a selection chosen for improved foliage and resistance to Witches Broom fungi
• ‘Chicagoland’, ‘Delta’, and ‘Windy City’ – several cultivars bred for oval form and an even quicker growth rate
• Prairie Sentinel – has a more narrow trunk

Although proper research should always be carried out to determine wildlife value of cultivars, much research has shown that natural ‘selections’ most often perform just as well as the straight species. If aesthetics are your primary concern, then by all means you should use the Prairie Pride variety over an invasive tree.

Uses of Hackberry Trees

Shade Tree / Street Tree

The Hackberry Tree has been used as a street tree in urban landscapes to provide shade and interest for many decades. They are planted in highway medians throughout the Midwest, and make an attractive tree providing interest year round. [2]

Native American Uses

There are 14 uses of Hackberry Tree documented by 8 different tribes. The primary use was food, as the berries would be ground and used as an ingredient in various dishes. [8]

Medicinal Uses

In addition to food, Native American Tribes did use the bark medicinally. a decotion of inner bark was made to treat gynecological issues as well as a sore throat or cold remedy. [9]

Lumber

Although not particularly strong, lumber made from Hackberry trees can be used for furniture and cabinetry when light colored wood is desired. It is about twice as hard as pine per Janka hardness. [10]

Final Thoughts

The Hackberry is a tough adaptable tree that is easy to grow, provides year round interest, and grows really fast. It makes a great tree for watching and observing wildlife, and will definitely stand out compared to other more common ‘suburban’ trees.

Although it has been heavily utilized by municipalities and state DOT, it really isn’t that common in residential plantings. Perhaps that will change as more states ban the sale of exotic invasive trees such as the Bradford Pear.

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