Winters can be very long and very
cold in many northern gardening regions. Preparation for this period is vital in
maintaining the survival and health of our landscape plants. This process, which can last
for up to five months in some areas, is started in mid-August and can continue until the
first snow flakes fall.
By late summer, the days are getting short, the sun is less
intense and nights are cool and frosts can occur at any time. The plants begin their
preparation for winter, as they store food reserves in the roots.
Grass, for instance, will survive better without fertilizing with
high nitrogen products past mid-August. Nitrogen feeds green leaves, and at this point in
the season, the plant is storing food.
By leaving the grass slightly longer with those last few cuts,
you allow greater leaf surface area for production of the food, as well as increasing its
ability to trap and hold snow.
A good snow cover ensures optimum conditions for survival through
the harshest winters. Measurements taken at ground level under six inches of snow indicate
soil temperatures to be just slightly below freezing.
To ensure that perennials, bulbs, trees and shrubs survive
winter, first and foremost, purchase hardy plants. Check with your Growise Centre for the
"climatic zone" in which you live. Ask for plants hardy to this region.
Removal of dead plant material helps protect plants from insects
and disease that may overwinter. It is however advisable to leave plant stalks at least
twelve inches long to trap snow. This is especially important in exposed areas.
Pruning is better left until early spring to avoid frost damage
to cut areas. Often late winter thaws create spring-like conditions for a short time
followed by a resumption of winter weather. During this time, plants may begin to come out
of dormancy. They begin active growth, only to be plunged back
into the deep freeze.
High plant losses are experienced during these thaws. Mulching in
fall reduces rapid changes in soil temperature during thaws, keeping plants dormant until
Also during early spring, many evergreen trees and shrubs can
begin active growth, before the ground is thawed. The plant is unable to draw moisture
from the frozen ground. As a result, top growth dries out. Browning of the needles and
needle drop occurs.
Water evergreens deeply in fall and place "tents" of
burlap or canvas around the tree but not touching the foliage. Usually they are supported
by wooden stakes. These allow air flow around the branches, but reduce the drying effects
of wind and reflected sun.
In areas prone to rodent (mice, rabbits) damage in winter, wrap
deciduous tree trunks with a protective covering in fall. A light coloured wrap will also
reflect strong rays from the sun and snow. Some trees are susceptible to
Many bulbs are planted in fall for spring blooming. Selections
are best in early fall but be sure to choose hardy bulbs for your area. Size of the bulbs,
and how cold your region gets during winter, dictates how deep they are planted. Tulips,
for example, are planted four to six inches deep, while smaller muscari are two or three
inches deep. Container-grown perennials can be planted up till early fall. They need some
time to establish some roots in their new location. Water well and regularly until frosts
kill the top growth, but don't saturate the soil. A mulch around the base of the plant
will also give more protection to the roots.
Some tender roses will need extra protection to survive northern
winters. Prune back stems to six inches long and cover with soil or mulch.
With careful preparation our landscape plants can be safely
tucked in for the long cold months ahead. Winter is only the pause before the next