Click below to listen to my 2 min. Garden Bite radio show: Plenty of precip in the Upper Midwest – what’s the long term effect?
Record rainfalls have thwarted many a gardener this past season. A lot of our plants developed fungal diseases, in particular those tasty tomatoes!
There’s also a long term problem with all that wet weather. Trees are dying with wet feet. It’s been documented in Nerstrand Big Woods where I live and in other places around the Upper Midwest.
According to a recent article through the Minnesota DNR, these wet conditions impact tree species differently. Tolerance of waterlogged soils is not well-understood, but trees that are intolerant of flooding include pines, basswood, white spruce, sugar maple, and red and white oak.
Alternatively, elm, red maple, ash, cottonwood, and tamarack can better tolerate having “wet feet,” although not forever.
Longer duration and frequency of wet conditions are harder on trees, and our abundant precipitation over the last several years has stressed trees in some areas. Also, flood-waters along rivers can dump large amounts of silt and sand over tree roots, causing them to suffocate and die.
Something many homeowners need to understand is that symptoms of flooding frequently do not show up for a couple of years in relatively flood-tolerant trees, but susceptible trees often die the next spring. Flooding stress can also make trees more susceptible to attack from insects and diseases.
Some symptoms of water stress include:
- leaf yellowing and loss
- small leaves
- sprouts along the trunk and branches
- crown dieback
This LINK from the MN DNR provides a lot of information on various topics related to trees this 2019 season. This PDF is Annual Health Report for 2018 of Minnesota’s forests.