Managing Ash Trees for the Long Run

By Scout Nelson

North Dakota gardening and forestry experts shared guidance on long-term tree planning as emerald ash borer slowly spreads across the state, reminding residents that decisions made today can affect landscapes for decades.

Tree growth depends on many factors, including species, planting site, water, sunlight, soil nutrients, and overall care. Some fast-growing trees can reach over 30 feet in about 20 years, while others grow much slower. These differences show how long-term planning shapes what yards and communities look like years later.

The arrival of emerald ash borer, often called EAB, makes this planning even more important. The insect was first found in the Midwest more than two decades ago and was discovered in North Dakota in 2024 near Edgeley. It has now also been confirmed in Fargo. While this spread is expected, it signals that time for planning is becoming shorter in affected areas.

EAB spreads slowly on its own, moving about half a mile each year. In areas close to confirmed locations, ash trees may begin to die within five to ten years. Dead ash trees become brittle and dangerous, especially near homes, sidewalks, or power lines. Removing dead trees later can be very costly and risky.

Homeowners have several options. One choice is removing ash trees early and planting new species. This reduces future risk and helps create a more diverse and healthier urban forest. Another option is chemical treatment. Products such as emamectin benzoate can protect ash trees but require injections every two or three years, which may be expensive over time.

Experts stress that chemical treatments are not recommended unless EAB is found within 15 miles of a location. In many parts of North Dakota, the insect has not yet arrived, making early treatment unnecessary and costly.

The key lesson is simple. Long lived plants like trees require long-term thinking. Choosing when to treat, remove, or replace ash trees now can lead to safer yards, lower costs, and healthier landscapes years into the future.

Photo Credit: gettyimages-paul-hartley