Trunk guards put on too early contribute to Frost cracks

Discussion in 'Maples' started by JT1, Oct 22, 2017.

  1. JT1

    JT1 Contributor 10 Years

    Likes Received:
    Euclid, OH USA
    Some prefer to use trunk guards to protect their maples from cold damage. It's now understood that putting the plastic guards on too early can contribute to Frost cracking of the trunk, which is the problem you are trying to prevent.

    A warm microclimate in between the plastic guard and the trunk prevents the tree bark from responding to the cool nights that triggers a natural response in the bark to "harden off" for Winter. This reduces cold hardiness in the area of the trunk being covered. In the microclimate moisture increases, the bark can become saturated and freeze splitting the bark as the frozen moisture expands.

    Consider using tree guards in early winter and removing them in late Spring. If you are protecting against rodents, consider using 4 peices of rebar driven into the ground with durable black plastic netting as a rodent barrier. It's hard to see and is less noticeable than the plastic tree guards (in my opinion). Save the tree guards for Winter and do not leave them on year round. Otherwise you will increase the chances for damage which is the thing you were trying to prevent in the first place.

    Tree guards could increase splitting
    "There also seems to be a relationship between increased splitting and the use of tree guards. Earlier studies have shown plastic trunk guards used to reduce SW injury, bark splitting or deer and rodent damage can actually intensify bark splitting (Spotts and Cervantes, 1994). If put on too early in the growing season, the guards inhibit the cold acclimation process in the fall, and result in an increased incidence of cold injury in the spring. The guards actually alter the microclimate of the bark in the protected region. Not only do the plastic guards reduce cold hardiness in the guarded region, but they also increase the moisture content in that region, resulting in increased susceptibility to mechanical injury, and thus splitting, caused by ice formation under the guard. Tree guards were originally used for cold injury protection and applied in late fall, however, in more recent years they are being left on year round for protection from deer. It is recommended that tree guards be removed in summer and re-applied in late fall or early winter. Leaving tree guards on year round increases the risk of SW injury and SW bark cracking."

    More information on the causes of split trunks:
    Landscape Trades - Diagnosing bark splitting problems: Part one
    Last edited: Oct 22, 2017
    maplesandpaws likes this.
  2. maplesandpaws

    maplesandpaws Active Member

    Likes Received:
    KS -> northern AL, USA
    Thanks for sharing JT :) Something you don't think about, but it makes a lot of sense.

Share This Page