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MNLA E-Training, Project Plant

Grower Perspectives

Richmond Area
Many Taxus (Yew), Pinus (Pine), Picea (Spruce), Thuja (Arborvitae), Rhododendron and Chamaecyparis with severe burn. Long established landscape Taxus have total defoliation above snow line. I have yet to see a Picea glauca (Alberta Spruce) that is not damaged to some degree. Extensive damage from rabbit, mouse, and deer feeding heavily due to the extreme cold and heavy snow levels. There will be a lot of shrubs misdiagnosed as winter damage, when the actual issue was the girdling of the cambium by rodents.  We are fortunate (and did our attention to detail) as there are very few problems with production plants in the houses. Hydrangea quercifolia (Oakleaf Hydrangea) are among the heaviest casualties in containers.

Saginaw Area
Our Taxus (Yew) are heavily winter burned. Most will grow out of this and will be fine. Thuja (Arborvitae) did fairly well except for a lot of deer damage as they were desperate for food. Abies concolor (Concolor Fir) are severely winter burnt in fields. Most deciduous trees seem fine. Would think there will be dieback on Acer palmatum (Japanese Maple) also.

West Olive Area
We are seeing a lot of animal browse damage due to lack of feed for them.  Broadleaf evergreens such as Ilex (Holly) and Buxus (Boxwood) are showing signs of winter desiccation, which is displayed by burned and discolored foliage. Evergreens in general are also showing similar winter desiccation. Overall it is a little too early to really access the true damage of the winter. Most plants seem to be responding all right, but plants are starting slow due to the cold. We will know a lot more in two weeks.

Central Ohio
Winter burn on some Taxus (Yew) varieties and Chamaecyparis (Falsecypress).

Grand Haven Area
We have seen a lot of desiccation in our Taxus (Yew) fields – anything above snow line is desiccated. We have seen a fair amount of split bark on our fruit trees, Prunus persica (Peaches) are the worst but see it in Pyrus (Pear) and Prunus (Cherry) also. In the landscape Picea glauca ‘Conica’ (Dwarf Alberta Spruce) have a lot of burn and some Rhododendron are also damaged. A little early to tell on perennials yet, but I would think we will see some damage also.

Michigan State University, Department of Horticulture
Statewide Perspectives
Broadleaved evergreens have been hit hard by the winter conditions. Damage includes foliage desiccation and death of terminal buds. The snow level indicates the line between healthy and damaged foliage. Please note, Even though the foliage is brown, it doesn’t mean that the stems are dead. To tell, scratch the stems with your thumbnail, light green is good, tan or brown is damaged. We have seen some flower bud damage on Cornus florida (Flowering Dogwood) and other flowering trees will also be affected. People can check flower buds on their ornamental trees by breaking off the bud; light green is good, tan or brown is damaged. Flowers buds may be killed, however, vegetative buds giving rise to new stems and leaves may be fine. Leaf and Stem buds can take a lot lower temperatures than flower buds.
Narrowleaved evergreen shrubs have also shown signs of winter damage.  The most obvious is Taxus (Yews). Again even though the needles are brown, it does not mean that the stems are dead.
The best advice we can give is to wait until buds break later in the spring. Time will tell if flower and leaf/stem buds are dead. What appears dead could be fine.

The most obvious issue that is showing up so far is winter burn on Conifers.   
We will also likely see dieback on some deciduous trees and shrubs, especially anything that might be considered marginally hardy. Liquidambar (Sweetgum), Cercis canadensis (Redbud), and Taxodium distichum (Baldcypress) are some examples of plants where we may experience some problems.
In most cases the best advice is 'wait and see'.  Winter damage can often appear worse that it really is, especially for some of the winter-burned conifers.  Buds may be completely unaffected even though the tree has extensive browning.  For deciduous trees and shrubs the same advice applies; it's best to let things flush out and then determine what's alive or dead and what needs to be pruned out.