Monster Tree Service of Rochester May Newsletter

Last month's newsletter on planting trees touched briefly on using mulch. This month, we are going to dive deeper into the topic of mulch. Did you know that mulch is not just about property aesthetics? While it does add flare and enhances the look of the landscape, it is also a very helpful tool for supporting tree growth during the spring.

Mulch can be very beneficial for green health. 

• Mulch helps improve the quality of soil by adding nutrients and increasing organic matter. This helps promote healthy root systems and improves water retention in the soil. 
• Mulch helps stop the germination of weed seeds by blocking sunlight and preventing seeds from reaching the soil. 
• Mulch acts as an insulator by keeping soil temperature at a consistent level throughout the year, which is beneficial for the plants. 
• Mulch helps keep moisture in the soil, which is beneficial for plants during periods of drought. 
• Mulch can also create a buffer zone that protects the trunk of the tree from injury caused by lawn mowers and trimmers. 

Woodchip mulch can be used for a variety of landscaping applications, such as around trees, shrubs, and flower beds, as well as on paths and walkways.

But there can be too much of a good thing. Loading up on mulch can cause serious harm to trees. Mounds of mulch, also referred to as a mulch volcano, can: 

• Trap moisture against the tree's bark which may encourage fungus and rot. 
• Trick feeder roots into remaining in the mulch rather than establishing a strong root system in the soil. This may cause stability issues and poor growth.  
• Increase the chances of girdling roots. Mounding the base of the tree with mulch can trigger reactive roots to grow. These adventitious roots most often grow in the same circular pattern as the mulch before competing for deeper soils. Over time, the roots gradually choke the tree; stopping essential nutrients from reaching the branches and leaves above ground. 

The root flare, or collar, is located where the trunk begins to widen and flare out.

So don't keep piling it on! A couple of tips to keep in mind: 

• Mulch should only be at a depth of 3-4". You should be able to see the root flare. The root flare is wider at the base of the tree. Your tree shouldn't look like a telephone pole going into the mulch or ground.  
• Mulch should not physically touch the tree trunk. You should stop once the mulch reaches the root flare of the trunk.  
• Use mother nature as your example – walk through the woods and identify the root flare of a tree. You will notice it is not covered in leaves or soil! 

Airspading allowed us to examine these tangled roots and make corrective pruning cuts to alleviate long-term root stress.

If you already have a mulch volcano, a trained arborist can help remove the volcano and correct any issues hidden by the volcano. Airspading is a safe practice that uses compressed air to remove mulch and soil around the base of the tree and expose the root system. Once the roots are exposed, the problem roots are identified and pruned or removed. When this work is done, you want to balance removing problem roots with leaving the tree enough roots for storage and uptake of nutrients. Trees with extensive root issues may need to have this process repeated over multiple years, so the tree has time to adapt to the root pruning before removing more roots. Proper mulching can help you avoid having to remove the tree or incurring the expense associated with airspade work. 

For additional information on mulching visit:

Consult a Monster Tree Service Arborist

University of Maryland Extension: Mulching Trees and Shrubs