Ash

Ash trees have long been a familiar part of Wisconsin’s landscape, valued for their strength, shade, and beauty. Among the common varieties are green, black, and white ash, each with unique characteristics that make them popular choices for planting in yards and public spaces. Yet, the future of ash trees in Sheboygan and across the state faces a serious threat from the emerald ash borer (EAB), an invasive beetle that has devastated ash populations. Understanding the types of ash trees, how to plant and care for them, and the risks posed by EAB is essential for anyone considering adding these trees to their property.

Types of Ash Trees in Wisconsin

Green Ash

Green ash is one of the most widespread ash species in Wisconsin. It grows quickly and adapts well to different soil types, making it a common choice for urban and rural planting. Its leaves turn a bright yellow in the fall, adding seasonal color to landscapes.

Black Ash

Black ash prefers wetter soils and is often found near swamps and wetlands. It has a slower growth rate compared to green ash but is valued for its strong wood, which has been traditionally used in basket making by Native American communities.

White Ash

White ash is known for its sturdy wood and symmetrical shape. It grows well in well-drained soils and is often planted as a shade tree. Its leaves turn a striking purple or red in autumn, offering a different fall palette compared to green ash.

Planting and Caring for Ash Trees

When planting ash trees, location and soil conditions are key. Ash trees generally prefer full sun and well-drained soil. Here are some tips for planting and care:

• Choose the right variety based on your soil and moisture conditions.

• Plant in a spot with enough space for the tree to grow both upward and outward.

• Water young trees regularly during dry periods to help establish roots.

• Mulch around the base to retain moisture and reduce weeds.

• Prune dead or damaged branches to maintain tree health and shape.

  
  

Ash trees can live for decades when properly cared for, providing shade and beauty to your property. However, planting ash trees today requires careful thought due to the threat of emerald ash borer.

The Threat of Emerald Ash Borer

The emerald ash borer is a small, metallic green beetle native to Asia. It was first detected in the United States in 2002 and has since spread rapidly, killing tens of millions of ash trees. In Wisconsin, the impact has been severe:

• Over 99% of untreated ash trees are expected to die as EAB spreads.

• By 2024, most ash trees in the southern two-thirds of Wisconsin are already dead or dying.

• Northern parts of the state are now experiencing rapid and widespread ash mortality.

  
  

EAB larvae burrow under the bark of ash trees, disrupting the flow of water and nutrients. This damage eventually kills the tree, often within a few years of infestation.

Why Planting Ash Trees Without a Treatment Plan Is Risky

Given the widespread damage caused by emerald ash borer, planting ash trees without a plan to protect them is not recommended. Here’s why:

• High risk of loss: Without treatment, new ash trees are likely to be killed by EAB within a few years.

• Costly removal: Dead ash trees pose safety hazards and must be removed, which can be expensive.

• Limited replacement options: Losing ash trees reduces diversity in the urban forest, which can affect local ecosystems.

  
  

If you want to plant ash trees, consider these options:

• Use insecticide treatments: Systemic insecticides can protect ash trees from EAB but require regular application.

• Plant resistant species: Some ash varieties show more resistance, but no ash is completely immune.

• Diversify your landscape: Include other tree species to reduce the impact of EAB and other pests.

  
  

Practical Steps for Sheboygan Residents

For residents of Sheboygan thinking about planting ash trees, here are some practical steps:

• Consult local experts: Contact the Sheboygan County Extension or local arborists for advice on ash tree care and EAB management.

• Monitor trees regularly: Look for signs of EAB infestation, such as thinning canopy, bark splitting, or D-shaped exit holes.

• Consider treatment early: If you have existing ash trees, early treatment can save them.

• Plan for diversity: Mix ash with other native trees like oak, maple, or basswood to build a resilient landscape.