Masterpiece Landscaping Blog

One of the great mysteries of landscaping in Minnesota is knowing all of the elements involved which cause so-called “winter burn” on our garden coniferous evergreens.  We do know exposure to the winter sun especially in mid to late winter, the location and genus of the “victim” are all contributing factors.

We also noted that the winter of 2008-2009 was one of the worst winters for winter burn.  We noted that some yews in full sun facing south or southwest in full exposure, in front of a stucco structure showed not a millimeter of any winterburn.  We also observed many Taunton spreader yews allegedly resistant to winter burn in full shade covered with brownout  byApril first.

We concluded that there are a variety of factors which cause winter injury to  susceptible evergreen conifers, not least of which is late summer watering and plant exposure to winter wind.

With autumn soon upon us, we will be confronted with “to water? or not to water? from mid October into November until snowfall.

I never had winterburn on any evergreen for 35 years on my grounds until the winter of 2007-2008.  I owned about 25 yews displayed one place or another in my landscape. My irrigation system is usually turned off around October 24th.  I was alarmed for yews when well grown and groomed are elegant shrubs or trees.  Most are located under some canopy of deciduous tree, just shady enough, I felt, to warrant confidence my plants were safe from winterburn…as they appeared to be for 33 years.

Last autumn as an experiment, I decided to stop irrigating the garden three weeks earlier, thinking I had allowed these yews to go into winter without sufficiently acclimating to the harsher temperatures and the winter environment in general.  I lost nearly 200 years of yew plant growth on my property, including a tree 25 feet tall.  Many lost were located in deep shade.

There have been some professional studies regarding winter burn on conifers in general, but information from them has been contradictory.  Some encourage watering regularly until snowfall.  Others recommend easing off on watering gradually in order “to toughen” the plants up.

On one point studies recommend…do not, as a rule, fertilize coniferous evergreens after  August 1.  Encouraging new growth on the plants delays “hardening” them off for the cold season.

The garden season this year, 2009, in the Twin Cities metropolitan area has been one of the driest and coolest in recorded history.  As a generalization we can predict that signs of autumn will arrive earlier and the coming winter will be earlier,  longer, and probably snowier.

The observing home owner will notice that foliage toward the  interior of  pines, arborvitae, junipers, especially and in general, of all evergreen conifers in our climate will begin to turn yellow.  Folks become alarmed thinking some disease has infested their evergreens.

In fact, however, there is nothing to worry about, for nature is doing nature’s thing.  These evergreen conifers are simply shedding the oldest needles of their crop as they do every autumn.  It is as predictable as a sugar maple or any other deciduous shade tree shedding all of its leaves at the end of each growing season.  We usually expect this ritual of nature in October, after all, that’s why we own leaf rakes.

Most Minnesota home owners call all coniferous evergreens “pines”.  My pine this and my pine is doing that…..even though the evergreen tree might not be a pine at all, but an arborvitae, or a spruce, a chamaecyparis, or yew, here a juniper or there a fir or hemlock.   Not all Minnesota evergreens are equal!

There are many “fish” in the Minnesota evergreen pond.  Most are easily distinguished one from another.

We at Masterpiece Landscaping  would like to invite interested home owners to learn more about these “pines” and their care, by offering a two hour session at our gardened grounds in Minnetonka tentatively scheduled for Saturday, August 29, at 9:30 AM.  Attendance limited to 20.  Call us at 952 933 5777 for further information.  There will be no admission charge.