Imprelis was released as an environmentally-friendly herbicide that could be incorporated into the tool box of lawn and landscape companies. Many companies started applying a new herbicide (manufactured by Dupont) in the spring of 2011. Unfortunately, Imprelis has been linked to the deformation, dieback and even death of landscape trees. The majority of the damage seems to be on Eastern white pine, white spruce, and Norway spruce trees.

A Warning Regarding Imprelis

Since Imprelis is a new class of herbicide, it is impossible to know with 100% certainly what the impact on our landscapes will be. Since most of the damage is relatively new, it is unlikely that we have seen the full scope of the damage. When making an assessment on Imprelis damage, professionals will need to apply information from what has been seen with other herbicides in the past. If you suspect damage:

1. Contact your Lawn or Landscape Company to see if and when Imprelis was applied. Try to obtain all pertinent information regarding the application process.
2. Take pictures of any potential damage to trees and plants.
3. You may need to get a professional assessment from an independent firm to analyze the extent of damage and help determine a course of action.
4. Determine the level of accountability from the company that applied Imprelis. Are they going to be involved and help in any way?
5. Depending on your situation, you may need to contact a law firm to proceed legally.

Comments Regarding Imprelis Damage

Symptoms of Imprelis damage have been widely variable but may include some of the following descriptions:

• New growth has twisted, distorted, weeping appearance (may remain green)
• New growth may have purplish needles
• The top of the tree may appear to be impacted while the rest of the tree looks fine
  

  Severely damaged new spruce growth showing typical twisting and distortion.

• In severe cases, all new growth may be distorted, disfigured or killed.
• Large portions of growth or entire tree may be killed in severe cases.
• For deciduous trees, most damage appears to be “cupping” or twisting of leaves.

Eventual Decisions

At some point the impact of Imprelis will come down to two questions:

1. Are my impacted trees going to survive?
2. If my trees survive, will their appearance be acceptable?

At some point, damaged trees will need to be assessed to identify which ones will definitely need to be removed and replaced. Many trees will also fall into the “wait and see” category. Unfortunately, we will need to wait until 2012 to assess how the trees leaf out before making the final decision and assessment on long-term viability and aesthetics.

Spruce tree showing considerable dieback to new growth.

Replacing and Disposal of Trees

Do not replace trees damaged by Imprelis within 120 days from the Imprelis application. Removal of trees may start in the fall of 2011, but replanting of trees should not start until May of 2012 (and possibly even later). It may be recommended to remove and replace the soil back-fill depending on site conditions. It is currently recommended that all trees killed by Imprelis be disposed at specific sites and not used as mulch for other plantings. It will be important to keep up to date with the latest updates and research regarding Imprelis.