www.arborage.com ARBOR AGE WINTER 2015 15
PLANT HEALTH CARE
by evaluating and categorizing landscape plants into Plant
Hardiness Zones. Starting at the Canadian border, Zones
are assigned in 10-degree increments down to the Mexican
border. Zone 1a plants need to be hardy down to negative 60
degrees Fahrenheit, while, on the other end of the spectrum,
Zone 13b plants are uncomfortably chilly at 65 to 70 degrees
Fahrenheit. This helps provide some guidelines on what temps
a plant may be able to tolerate, but it does not mean that they
can tolerate it all the time. A paper birch may be able to survive
through weeks of negative 40 degrees Fahrenheit in midwinter,
but would likely die in 24 hours if exposed to those temps in
midsummer. Plants must first acclimate to the cold before they
can withstand it.
The process of getting ready for the coming winter begins
with the shorter days and cooling temps of autumn. Chlorophyll
production ceases, revealing the bright reds, yellows and orange
pigments we all love so much. As this is going on, trees are
actively moving carbohydrates into storage tissues in their
trunks and roots and reallocating their moisture reserves as well.
Water management is the biggest key to surviving subfreezing
temperatures, as trees are comprised primarily of water. Water,
of course, expands when it freezes; and this expansion will
rupture the walls of plant cells causing the death of the cell, and,
if widespread enough, the death of the tree.
Plants all around the temperate world have evolved different
Birch trees use deep supercooling.
FOR NATURE'S WORST
T H E B E S T R E S O U R C E S P R E P A R E D
Nothing can prevent catastrophic weather events, but you can be prepared. Before the storm, Asplundh can help you manage
the unexpected with our pre-planning services and ready-to-respond storm agreements.
When the storm hits, Asplundh's unparalleled resources are at your fingertips. From one crew to hundreds, you can count on
our specially-trained staff and fleet of standard and specialized equipment to safely and efficiently help you restore service.
Asplundh's innovative Automated Vehicle Management System and Truck-as-a-Hub technology give you real-time connectivity
to our crews, allowing for more efficient response coordination. Mother Nature's worst – Asplundh is ready.
ASPLUNDH.COM • 1-800-248-TREE
