Tree Species We Care For: Hickory Trees

Beloved for their edible nuts, strong wood, and gorgeous fall color, hickories are some of the most valuable trees in all of Southeast Michigan. They aren’t deliberately planted very often, but it’s always nice to see volunteers sprout or retain existing individuals during construction projects. 

But like all trees, hickories require proper care and maintenance to thrive and reach their full potential. We’ll share some of the most important things you’ll want to do and outline potential warning signs you’ll want to watch for below. 

Common Hickory Traits

While hickories are represented by a number of different species, and each has its own traits and tendencies, most hickories share a few common traits, including:

• Very hard, strong wood. Hickories are famous for producing very hard wood. That’s part of the reason they are so valued in the timber industry, where they’re used in the manufacture of flooring, furniture, tool handles, sporting goods, and cabinetry.  
• A large taproot. Hickories spend the first few years of their lives investing heavily in the production of a large taproot. This is important, as it makes hickory trees both more drought tolerant once established and helps keep young hickories stable during their early life. 
• A slow growth rate. Because of the two previously mentioned traits, hickories are remarkably slow-growing trees. The U.S. Forest Service reports that seedlings growing in fertile sites in the Midwest often go from three inches tall in their first year to just 17 inches tall by year five. 
• Pinnately compound leaves. Hickory leaves are composed of multiple leaflets arranged in pairs along a central stalk called a rachis. Different species have different numbers of leaflets; for example, pignut hickories often have five to seven, while pecans may have as many as 17.
• Golden fall foliage. While pecans often lose their leaves before developing much color, most other hickories produce attractive fall foliage in the gold to bronze to yellow portion of the spectrum. This provides a lovely contrast with the red tones common in maples and some oaks.
• Many are shade-tolerant when young. Hickories require ample sunlight at maturity to thrive, but many begin life under the deep shade of the forest floor. This can make them ideally suited for shaded portions of some properties, where few other trees thrive. 

Additionally, all hickories produce edible nuts, though some are not palatable to people. These nuts are typically very important food sources for local wildlife, ranging from chipmunks to pigs. 

Michigan’s Hickory Species

There are nearly 20 hickory species found worldwide, with roughly 11 being native to the United States. Four of those are native to Michigan and one more is sometimes planted in our state, despite not being historically native. 

Shagbark Hickory 

As its common name suggests, the shagbark hickory (Carya ovata) is covered in long, vertical strips of bark that peel away from the trunk, giving mature individuals a distinctly “shaggy” appearance. In fact, this bark is so distinctive that it allows for instant identification and can be spotted from quite a distance. 

Capable of reaching 100 feet in height, the shagbark hickory (like most hickories) is a long-lived tree. One specimen was documented as reaching more than 350 years of age. 

Pignut Hickory 

Typically most common on dry ridges, the pignut hickory (Carya glabra) can also be found in damper areas on occasion. Generally reaching heights of about 80 to 90 feet, the pignut hickory is slightly smaller than the shagbark and is sometimes described as having a more graceful growth habit. 

Like most other hickories, the pignut grows very slowly. But also like most other hickories, the pignut has very hard, durable wood and an extensive root system — both factors that often keep hickories standing in winds that topple other nearby species. 

Shellbark Hickory 

With the largest nuts of any hickory species, the shellbark hickory (Carya laciniosa) provides an abundance of food for people and wildlife alike. It usually remains below 100 feet in height, though it occasionally exceeds 110 feet, such as is the case with the National Champion Tree for the species. 

Shellbark hickory is often confused with shagbark hickory, largely because mature individuals of both species tend to develop the same kind of “shaggy” bark.   

Bitternut Hickory 

A close relative of the pecan tree (Carya illinoisensis), the bitternut hickory (Carya cordiformis) is the shortest-lived hickory species. However, the shortest-lived hickory is not necessarily a short-lived tree; it often lives for approximately 200 years. 

The bitternut hickory is quite large and often reaches heights of 115 feet, with occasional specimens reaching 150.

Pecan Tree 

Although its common name leads to some confusion, the pecan tree (Carya illinoisensis) is technically a type of hickory tree. In fact, it’s the largest hickory tree in the world, with some individuals reaching 140 feet or more. 

Pecan trees aren’t native to Michigan; they’re historically restricted to the Mississippi River Valley and adjacent regions from Texas northward into the Midwest. However, thanks to the tasty nuts they produce, they’ve been planted across the country, including portions of Michigan. 

How to Care for Your Hickory Trees

Hickory trees are often tough as nails. They’re often the trees that survive after others have perished following a severe storm or disease outbreak. But to give your tree the best chance of remaining healthy and looking its best, you’ll want to do the following:

• Apply mulch over the root zone. A 2- to 4-inch-thick layer of organic mulch will help retain soil moisture, provide organic matter to the roots, discourage weed growth, and moderate soil temperatures. Just be sure not to pile mulch up against the trunk, as this invites decay. 
• Provide supplemental water during extended droughts. Hickories are relatively drought tolerant once established, but they may still benefit from additional water during dry periods. Just try to water deeply and infrequently to encourage deep root development. 
• Protect the roots from damage. Mulch will help protect roots from mower damage and low-level foot traffic, but you also need to prevent heavy vehicles from driving over the root zone. Also, avoid construction or grading projects near the tree, as these activities often result in cut roots. 
• Monitor it closely for signs of trouble. Because early detection is helpful for treating many tree pests and pathogens, it’s important to examine your trees periodically. Be sure to inspect all portions of the tree, using binoculars to see the upper portions if necessary. 
• Fertilize it when appropriate. Fertilizer can be helpful for maximizing growth and encouraging a full, lush canopy, but it should only be administered after first obtaining a soil test. This way, you can select a fertilizer that addresses the specific nutritional deficiencies present. 

Trimming & Pruning Your Hickory Trees

Hickories don’t require a lot of routine pruning, though it is generally a good idea to have a professional arborist perform a crown cleaning — the selective removal of dead, dying, or decayed branches — every three to five years. 

Crown cleanings can help keep your tree safe and proactively prevent it from dropping potentially hazardous branches. It also gives a tree-care professional the chance to inspect your tree’s canopy and spot any potential signs of trouble. 

It may also be necessary to have a hickory tree pruned when it presents site-use conflicts, blocks desirable views, or begins contacting a home or commercial structure. 

Common Hickory Tree Problems in Michigan

Hickories aren’t susceptible to many of the big-name tree threats, such as emerald ash borer, Dutch elm disease, or even oak wilt. But there are a few issues they can suffer from, including the following:

• Hickory Anthracnose: A fungal disease that causes brown blotches to form on the leaves, anthracnose doesn’t usually kill hickories outright, though it can cause aesthetic issues. 
• Hickory Bark Beetles: Hickory bark beetles can cause crown dieback, but they’re generally considered a symptom, as they only tend to cause problems for stressed hickory trees. 
• Fungal Cankers: A variety of fungi can cause hickories — especially those that are already battling other stressors — to develop cankers that’ll lead to branch death or canopy dieback. 
• Hickory Decline: A gradual loss of vigor caused by drought, root damage, soil compaction, and other stressors. Symptoms often include crown thinning, branch dieback, and reduced leaf size.
• Soil Compaction: One of the most serious threats to hickory trees, soil compaction reduces the soil pore size, which limits the movement of air and water through the soil. 
• Leaf-Chewing Insects: A variety of insect species feed on hickory leaves, including several caterpillars. However, mature, healthy trees are rarely harmed from low-level infestations. 

Signs Your Hickory Tree May Require Removal

Despite being remarkably tough trees, hickories can become hazardous and require removal. If you notice any of the following signs or symptoms, be sure to have your tree evaluated by a professional arborist. 

• A sudden or increasing lean. Not all leans indicate an increased risk of failure, but trees that begin leaning suddenly or more than they previously did may be at imminent risk of falling. 
• Cavities in the trunk or major branches. Cavities may be beneficial to wildlife, but they’re often associated with extensive internal decay, which may weaken the tree significantly. 
• Soil disturbances near the trunk. Cracking, mounding, or heaving soil can indicate soil instability, root failure, or both and place the tree at increased risk of windthrow. 
• Premature fall color or leaf drop. Many tree pests and pathogens can cause leaf disturbances. Some of these may also be associated with weak wood, making the tree a potential hazard. 
• Cracks in the trunk or branches. Cracks are often a serious sign that the tree’s wood fibers are already failing, which increases the risks of injuries or property damage. 

Treemendous Tree Care: Helping Care for Michigan’s Amazing Hickory Trees

Because they’re not always easy to install or transplant, hickories really should be treasured by those fortunate enough to have them growing on their properties. But to be sure that your hickory tree thrives and lives a long, healthy life, you’ll want to partner with a professional arborist, who can provide the kind of support you need. 

Treemendous Tree Care has been providing exactly that kind of assistance to communities across Southeast Michigan since 2019. Whether you have one hickory tree or a dozen, our team can provide the expert guidance and maintenance your trees need.

Contact us today to schedule your free estimate.  

Sources & References

• University of Michigan Herbarium – “Michigan Flora Online: Genus Carya”
  An authoritative botanical database detailing the hickory genus (Carya) within Michigan. It maps the distribution, morphological keys, and native habitats of distinct species like shagbark, bitternut, and pignut hickories across the state.
  https://michiganflora.net/genus/Carya
• USDA Forest Service (Southern Research Station) – “Silvics of North America: Carya cordiformis”
  A comprehensive biological profile on the bitternut hickory (Carya cordiformis). This silvical guide covers its extensive geographic range, soil and climate adaptation traits, reproductive cycles, and role in forest succession.
  https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/carya/cordiformis.htm
• USDA Forest Service (Southern Research Station) – “Silvics of North America: Carya glabra”
  A detailed technical summary focusing on the pignut hickory (Carya glabra). It explores the tree’s wood characteristics, environmental tolerance, lifecycle, and common wildlife dependencies.
  https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/carya/glabra.htm
• Michigan Department of Natural Resources – “Michigan Species: Shagbark Hickory”
  An educational conservation resource highlighting the shagbark hickory (Carya ovata). It describes how to recognize the tree by its distinctive peeling bark and outlines its high value to regional ecosystems and human timber use.
  https://www.michigan.gov/dnr/education/michigan-species/plants-trees/shagbark-hickory
• National Champion Tree Program – “Carya laciniosa (Tree ID: 6332)” 
  The registry profile for a historic, record-sized shellbark hickory (Carya laciniosa) located in Culpeper County, Virginia, documenting its monumental point score, height, trunk circumference, and multi-decade tracking history. 
  https://nationalchampiontree.org/championTree/6332