Trees We Care for: Oak Tree Care and Service Guide  

Few trees are as impressive as a vibrant and healthy oak. And fortunately for those of us living in the Great Lake State, oaks are everywhere! In fact, they’re not only numerous but also diverse, with more than a dozen species being common to residential and commercial properties alike. 

But as with all trees, oaks require proper care and support to thrive. We’ll share some of the most important facts about Michigan’s oaks below, so that you can better understand your trees and know how to keep them as healthy as possible.     

Michigan’s Oak Tree Species

A number of oaks are native to Michigan, and there are also a variety of non-native species that can thrive in our region. We’ll share the most common oaks you’re likely to see in residential, suburban, and urban properties across the state below.  

Native Michigan Oak Species

There are approximately 10 oaks native to the state of Michigan. These include:

1. White Oak (Quercus alba): A beautiful, long-lived, and widespread oak species that is known for its strong wood, wildlife value, and iconic round-lobed leaves.
2. Swamp White Oak (Quercus bicolor): Common in low-lying wetlands, this oak’s scientific name is a reference to its leaves, which are glossy green above and whitish below.
3. Bur Oak (Quercus macrocarpa): A larger, hardy, and drought-tolerant oak with deeply lobed leaves and very distinctive, “fringed” acorn caps.
4. Chinkapin Oak (Quercus muehlenbergii): A relatively uncommon oak that grows best in limestone soils and has leaves that resemble chestnut leaves.
5. Post Oak (Quercus stellata): A hardy, drought-tolerant Michigan oak that thrives in dry, sandy soils and bears thick, cross-shaped leaves.
6. Northern Red Oak (Quercus rubra): One of the fastest growing and most common oaks in Michigan, the red oak is a prized shade tree.
7. Black Oak (Quercus velutina): A large oak with dark, blocky bark and fuzzy winter buds, it resembles the red oak but prefers drier sites.
8. Pin Oak (Quercus palustris): A lowland oak with characteristic downward-sweeping lower branches that produce an attractive silhouette. 
9. Scarlet Oak (Quercus coccinea): Perhaps the most colorful Michigan oak during the autumn, the scarlet oak thrives best on sandy uplands.
10. Northern Pin Oak (Quercus ellipsoidalis): A northern cousin of pin oak, this species prefers drier, sandier soil than its close relative. 

Common Non-Native Oak Species in Michigan 

Because there are so many oak species native to Michigan, we don’t need to import very many from other locations. However, the following four species are sometimes planted in our area:

1. English Oak (Quercus robur): A European oak species that’s often planted for its stately form, this tree has long acorns and leaves with rounded lobes.
2. Shumard Oak (Quercus shumardii): A fast-growing red oak from the southeastern U.S. that often tolerates urban locations. 
3. Sawtooth Oak (Quercus acutissima): An Asian oak species that’s easy to identify by noting its long, saw-toothed leaves and fringed acorns.
4. Overcup Oak (Quercus lyrata): A southern oak with acorns almost completely enclosed in their caps, it can tolerate relatively damp soils.

How to Care for Your Oak Trees: A Michigan Homeowner’s Guide

Oaks have been living in Michigan for millions of years, so most of our native species have evolved to thrive in our local climate and soil. However, because humans have altered the land in many ways (especially as it relates to the soil composition and structure), most oaks will benefit from a little additional support. 

Keep the following things in mind when trying to keep your oaks looking their best. 

• Always plant the right tree in the right space. If you’re considering adding new oaks to your property, be sure to select species that’ll work well in the intended location. Be sure to consider not only the amount of space available, but also the sun exposure and soil characteristics of the site.  
• Mulch your trees properly. A 2- to 4-inch-thick layer of organic mulch will help protect your tree’s roots, retain soil moisture, and improve soil structure. Just be sure to avoid placing mulch against the tree’s trunk, as this can trap moisture and lead to decay. 
• Protect your trees from damage. Trees do not heal from wounds; they can only compartmentalize or seal them off. Accordingly, it is important to protect the base and trunk from mower or string trimmer damage, as well as other threats. 
• Provide additional water when appropriate. Mature, established oaks are generally somewhat drought tolerant, but it can be helpful to provide supplemental water during periods of high temperatures and low rainfall. And newly transplanted trees should always receive supplemental water for the first year or two.  
• Apply fertilizer when needed. Oaks growing in forests don’t require any fertilization, but those living in residential or commercial properties rarely receive enough nutrients to thrive. Just be sure to perform a soil test first, so that you can address the specific deficiencies present. 
• Monitor your trees regularly. Because some oak pests and diseases can lead to very rapid decline, it’s important to monitor your trees regularly. If you notice any troubling signs, ranging from crown dieback to the presence of mushrooms, contact a professional arborist immediately. 

Trimming Oak Trees in Michigan

Oaks often require pruning at various times in their lives. This helps to instill proper branching structure, eliminate problematic branches, and keep them as safe as possible. However, proper tools and techniques are necessary to avoid harming the trees, and they must even be trimmed at specific times to protect them from disease. 

A few of the most important aspects of trimming oaks include:

• Timing: Avoid pruning oaks between April and July to reduce the risk of spreading oak wilt.
• Purpose: Only prune oaks when necessary, such as to remove dead, diseased, or hazardous limbs.
• Technique: Use proper pruning cuts to encourage compartmentalization and minimize decay.
• Tools: Always use sharp loppers, pruning saws, or chainsaws to make clean cuts. 
• Structure: Structurally prune young oaks to encourage the development of a balanced canopy.
• Sanitation: Disinfect pruning tools between cuts and between trees to prevent spreading pathogens.

Additionally, it’s important to understand that — for safety’s sake — homeowners and property managers should never use a ladder to prune a tree, nor should they attempt to trim branches above their shoulder height. This means that, in practice, pruning any tree that’s more than about 10 feet tall is a job for professionals.  

Common Oak Tree Problems in Michigan

There are a number of pests and pathogens that attack Michigan oaks, and it is important to be able to spot the signs of them, so that you can get your trees expert care when necessary. This is especially important given the fact that some of these problems can kill oaks in a matter of weeks. 

• Oak Wilt (Bretziella fagacearum): Oak wilt is a lethal vascular disease that causes sudden wilting, browning, and rapid leaf drop. Spread by root grafts and sap-feeding beetles, oak wilt may kill red oaks in a few weeks; white oaks tend to die more slowly, over the course of several years.   
• Anthracnose (Apiognomonia quercina): A fungal disease that’s most common during cool, wet springs, anthracnose causes irregular brown or black blotches on leaves, distorted leaf shapes, and premature defoliation. While stressful, anthracnose usually only kills oaks that suffer from the disease repeatedly.  
• Bacterial Leaf Scorch (Xylella fastidiosa): A slow-progressing disease that is spread by leafhoppers and other insects, bacterial leaf scorch causes a tree’s leaf margins to turn brown and exhibit a yellow or reddish halo. Symptoms often begin in the late summer and worsen year after year.  
• Tubakia Leaf Spot (Tubakia dryina): A fungal leaf disease that causes small brown or reddish spots on mature leaves in late summer or early fall, Tubakia leaf spot resembles anthracnose. However, it usually appears later in the season and rarely causes significant leaf distortion.  
• Armillaria Root Rot (Armillaria spp.): A widespread fungal disease that causes slow dieback and decline in oaks. Armillaria triggers symptoms including crown thinning, yellowing leaves, and branch death. You may also see honey-colored mushrooms in the autumn.   
• Hypoxylon Canker (Hypoxylon atropunctatum): A stress-related fungal pathogen that causes large, sunken cankers on trunks and major branches, hypoxylon canker causes bark to slough off, revealing silvery-gray or brown fungal mats. It’s most common in oaks already weakened by drought, root injury, or other stress. 
• Two-Lined Chestnut Borer (Agrilus bilineatus): The two-lined chestnut borer is a flatheaded borer that attacks stressed oaks, especially red oaks. The insect larvae cause the bulk of the damage, as they feed beneath the bark, girdling the branches and disrupting water flow.  
• Oak Leafroller (Archips semiferanus): A caterpillar pest that rolls or ties leaves together with silk and feeds within them. These insects usually only cause temporary and cosmetic damage, but repeated defoliation can weaken oak trees.  
• Spongy Moth (Lymantria dispar): Formerly known as gypsy moth, this invasive caterpillar defoliates oaks in outbreaks. The larvae feed voraciously on leaves in late spring and early summer, and they can often strip entire trees of their leaves.  

Because large oaks may require crane-assisted removal if they become structurally compromised, it’s always wise to contact a professional arborist at the first sign of trouble. 

Signs Your Oak Tree May Require Removal

While most oaks are capable of reaching very old ages (some currently living oaks are estimated to be more than 1,500 years old), they will all eventually die or simply become too dangerous to leave standing. Only a professional arborist can determine whether an individual oak requires removal, but there are a variety of signs you’ll want to watch for, which may indicate trouble. 

Some of the most troubling signs to watch for include:

• Large Hollows: While many oaks develop hollow cavities that don’t cause the tree to die or collapse, it’s always important to have them inspected by a professional arborist. 
• Significant Cracks: Large cracks — especially horizontal cracks in the trunk — signify that some of the wood fibers have snapped, putting the tree at risk of failure. 
• Narrow Branch Junctions: Branch unions that are more V-shaped than U-shaped may trap bark between the stems, which will predispose them to failure. 
• Mushrooms or Conks: Mushrooms and conks are the fruiting bodies of fungi, which may cause serious decay and damage to the tree’s trunk, roots, or large branches. 
• Shifting Soil: Shifting or mounding soil indicates that the tree’s roots may be decaying, or the soil can no longer support the tree’s weight. 
• Prior Limb Drop: Unfortunately, trees that have already dropped large branches (not small twigs — that’s a normal process) are more likely to drop additional branches in the future. 
• Sudden Lean: While a gradual lean that develops over many years or decades may not be a big problem, sudden leans are almost always a tree emergency requiring immediate attention. 
• Crown Dieback: Crown dieback is associated with a variety of potentially serious oak diseases, including some that can kill in a matter of weeks. 
• Insect Activity: Termites, carpenter ants, and boring beetles may either cause a tree’s decline or signify that some of the internal wood has rotted or decayed. 
• Poor Taper: Oaks that look like poles sticking up out of the ground without much change in diameter may not be able to survive strong winds. 

Note that if you do have an oak tree removed, you’ll likely want to have the resulting stump ground down below grade. This will not only prevent the problems associated with leaving stumps behind (ranging from pest-related issues to reduced property curb appeal), but it may also help reduce the chances of spreading some diseases. 

Treemendous Tree Care: Providing Oak Tree Care in Clinton Township, MI

No matter what kind of oaks you have on your property, it’s important to get them the kind of care they deserve. This will help give them the best chance of remaining healthy and living for many more decades. 

Treemendous Tree Care can help provide exactly this — we care for all of Michigan’s native oaks as well as those non-native species that are commonly planted in the area. Contact us today for all of your tree pruning or tree removal needs. We’ll be happy to provide an on-site assessment and itemized estimate for the services needed.