Masterpiece Landscaping Blog

November 12, 2014

It has been reported that within 48 hours, the Temperature here Will Reach -3 degrees Fahrenheit

Filed under: battling the Minnesota climate,shrubs and trees — glenn @ 4:15 pm

Imagine such a temperature forecast in these days of ‘POLITICAL GLOBAL WARMING!” Anything for a vote!

Fortunately, in the part of the Twin City metropolitan area where I live, about three inches of snow fell a few nights ago. Fortunately too, the half-acre of landscaped garden I manage has already been covered ‘naturally’ by four inches of fallen leaves blown in mostly from neighbors’ mature oak, maple, and cottonwood trees.

Quiz question: Which of these trees, oak, maple, and cottonwood supply the most valuable protection to woody plants and herbaceous perennials from ‘foreign’ winter weather…meaning extreme winter freeze, absence of snow cover, absence of autumn moisture, or a shocking, extended ‘heat wave?…..

Why?

Maples? Well, it does depend upon the maple. By far the worst leaf fall, that is the most damaging, even a potential killer to herbaceous perennials and newly planted smaller woodies are the fallen leaves from Norway and Sugar Maples and their cultivars. Red and Amur maple leaves barely exist to any size even when displayed on the trees to cause trouble one way or any another…..except the leaves are very beautiful when lying on gardened ground for a week or more after leaf fall. Sugar and Norway Maples have broad, thick-textured leaves slow to decay and easy to paste together when clumped in masses. They can cause rot by smothering small under-story plants beneath their fall.

Cottonwood leaves fall early-on in autumn. By late September they already have dried and shriveled to some extent. They can easily be mowed up by mowing the lawn, and ignored if fallen anywhere else. They just don’t seem to matter much…..So what is left?…….the best God-sent leaves in our ‘half’ of the North American continent where their trees can live are the leaves of the Oak…..anyone of them you wish to name.

And now, the answer why. The oak leaf when fallen shrivels a bit while drying becoming crenulated. The dryness and the crenulating, that is, the curling of the leaf edges, entraps air…..Nature’s marvelous ‘natural’ insulator where ever these oaks happen to have been ‘acorned’.

The fact this Arctic wave is hitting this area so soon in our seemingly eternal winter is worrisome. Many new woody cultivars, both deciduous and conifer, although marked for horticultural zone 4, are not ‘designed’ to endure such a cold snap so early in the season. Furthermore, despite what the label might say regarding hardiness, the where and how the plant was planted, whether to the North, or South, the quality of the soil, amount of moisture throughout the Autumn, and “who” is the plant’s neighbor, has a lot to do whether it will be
“discovered” dead by May Day next Spring.

DO NOT ENTOMB CONIFERS OF ANY KIND WITH A GIRDLE OF ANY MATERIAL IN AN ATTEMPT TO ‘HELP’ THEM GET THROUGH ANY WINTER IN OUR NORTHLAND! If you have any worries from browning on the south or southwest side of these plants from previous years, protect them by placing something shade-providing to the south-southwest of the cherished evergreen.