©
Janet Davis
Winter
can be rough on a garden. Too cold and
it tests the mettle of plants growing at the limit of their hardiness
range. Too warm and it can prompt
premature budding (often disastrous, in the tree-fruit industry). Too much wet snow or heavy ice and fragile
tree and shrub limbs are at peril. Too
little snow and certain tender plants are deprived of the natural insulation
that a deep, snowy blanket provides.
Too windy and it can wreak havoc with slender rose canes or dessicate
exposed evergreens.
Winter is
no less tough on gardeners. It forces
them inside to catch up on all those household chores that came to an abrupt
end with the first warm rays of spring sun.
It reduces them to mindless January puttering with African violets and
bored February tinkering with grow lights—pale imitations of gardening in the
great outdoors. And once those glossy
seed catalogues arrive, 
winter turns the most rational, circumspect gardener into a
wild-eyed spendthrift who can blow the family fortune on obscure oenotheras or
prized primulas.
Winter
may indeed be cruel, but gardeners who tend to a few important outdoor chores
now can at least endure those long, dark months with the satisfaction of
knowing that their gardens will be in fine trim, come April.
Tidy the flower border to lessen the load in spring. Pull up and compost annuals. Cut down and remove all the foliage of any
plants that suffered fungal diseases or insect pests to curb reoccurence next
season. Cut back herbaceous perennials
to 6-8 inches (15-20 cm) leaving some
growth at the base to trap snow, but allow ornamental grasses and plants with
attractive seedheads (e.g. snakeroot, blackeyed susan and sedum) to remain standing
to give form to the winter garden. Don’t cut back woody plants like artemesia
and lavender; trim these in spring.
Rake your leaves from the lawn before snow falls.
It’s easy to ignore that last cleanup, but sodden autumn leaves can smother the
lawn, preventing photosynthesis just as turfgrass is working to establish the
strong root system that will carry it through winter.
Compost your leaves rather than packing them up for
your city to recycle. Brown autumn
leaves are rich in carbon, an essential component of the composting process and
needed in equal parts with nitrogen-rich green material such as kitchen waste,
weeds, green grass clippings, coffee grounds and cattle or sheep manure. Store bags or baskets of autumn leaves in an
out-of-the-way spot until they’re needed for the compost next spring, or pile
them up in a corner of the garden where they’ll be partially decomposed by May,
making excellent organic humus. And be
sure to leave a thin layer of fallen leaves around shrubs, trees and perennials
to act as a natural mulch, to return vital nutrients to the soil, and to
provide food for foraging earthworms in early spring.
Lift tender summer bulbs, tubers and
corms such as
begonias, dahlias, caladiums, callas and canna lilies after the first light
frost, but before a killing frost. Shake
off the soil and leave bulbs in a cool, airy spot to dry with their foliage
still attached. Once the leaves have
yellowed, cut them off, leaving about an inch of stem. Dust with garden sulphur, if desired, to
prevent disease and decay and store the bulbs in dry peat moss, sand or
vermiculite in an airy, dark, cool spot with an ideal temperature of 5-15C
(40-60F). Dahlias need temperatures no
warmer than 8C (45F) to prevent sprouting.
Peel off the old gladiolous
corms and store the young cormels in a paper or mesh bag in the same airy, cool
conditions. Read more about
storing tender bulbs.
Empty soil from
terracotta pots and
bring them indoors or turn them upside down to protect them from gathering
moisture, then freezing and cracking.
Plant lots of spring bulbs to ensure a beautiful display next year. Early-blooming bulbs like snowdrop (Galanthus) and winter aconite (Eranthis) should be planted as soon as
they become available. Narcissus benefit from early planting, by early-mid
October (depending on climate), to encourage strong root growth. But tulips and crocuses should be planted
when the soil is very cool, ideally between mid-October and freeze-up. And don’t forget that, apart from spring
bulbs, this is also the time to plant
hardy alliums, lillies and camassias.
Feed your lawn in late October to early November to
promote strong root growth in spring.
Although the grass is no longer actively growing, the roots are still
actively absorbing nitrogen which they store until the following spring, making
for better winter recovery. Timing of
this application is critical; the grass should be green but no longer growing.
Lower the blades on your lawn mower to about 1.5 inches (3.75 cm) for
the last cut in autumn. This shorter
final mowing helps prevent snow mould diseases which can take hold in long
grass during wet winter months.
Protect your roses, specifically hybrid teas,
grandifloras, floribundas, miniatures and English David Austin types, by
hilling a mound of ordinary garden soil (not lightweight planter mix) at their
base to a depth of about 12 inches (30 cm).
Or use a mesh or fibreglass rose collar filled with dry autumn leaves or
soil. Hilling-up protects the bud union
or graft point joining the rootstock with the cultivar rose from sustaining
frost injury. Wait until there’s been a
hard frost, usually in November, to avoid smothering a rose that hasn’t yet
gone dormant. Hold off on pruning
until spring, but shorten the canes of taller cultivars to prevent them from
whipping around in winter wind. Once the ground freezes, mulch borderline-hardy
plants and plants like coral bells having evergreen crowns that tend to heave
out of the soil during winter’s alternate freeze-thaw cycles.
Pot up some spring bulbs to force in an old fridge, cool garage or
basement cold room during winter.
Daffodils, crocuses, hyacinths and certain tulips are good candidates
for forcing. After planting and watering
bulbs, place in a dark spot where temperatures stay between 5-10C
(40-50F). Check frequently, making
sure the bulbs stay moist. When shoots
have grown a few inches above the soil surface, remove the pots to a cool spot
out of direct sunlight. When buds have
formed and are about to open, move the pots to the room where you wish to
display them; transferring them to a cool spot at night will help blooms last
longer. Amaryllis and paperwhite bulbs
don’t require cold-forcing and can be potted as soon as they become available.
Fall is generally a good time to
transplant or plant many trees and shrubs, since root growth still occurs even at cooler
temperatures and rainfall is usually plentiful. Some species, however, should only be spring-planted (e.g. birch,
red maple, 
magnolia, cherry) so it’s best to consult with your garden
center first.
Thoroughly water evergreens before
freeze-up to cut
down on sun scalding as leaves transpire moisture during brief winter
thaws. If broadleaf evergreens like
rhododendrons are exposed to strong afternoon sun in winter (they should
ideally be planted facing north or east), construct a shelter by stapling
burlap to wooden stakes. Conifers
prone to sunscald, e.g. Alberta spruce and gold cedar, can be wrapped lightly
with burlap, and upright conifers prone to to ice damage can be held firm with
nylon netting.
Clean leaves out of your lily pond to prevent the formation of toxic
methane gas, should they decompose under water. If methane builds up under even a thin layer of surface ice, it
can kill overwintering fish. And if
fish are left in the pond over the winter, use a de-icer to keep a section of
the water surface ice-free. Unless your
pond has a deep area that doesn’t freeze, remove hardy water lilies to a garage
or cool basement room where they can be stored, with frequent watering, until
spring.
Fill your birdfeeders to nourish migrating birds as they
pass through on their way to winter homes, and keep feeders full for bluejays,
nuthatches, chickadees, cardinals and other birds that stay around all
year.
Clean your garden tools and oil any movable parts. Have the lawnmower and shears sharpened now
so they’re all ready for spring. Drain
the garden hose and store it where it won’t freeze. Drain and turn off any outdoor taps.
Adapted from a column that appeared
originally in Toronto Gardens