The Rural Voice, 1979-05, Page 48Gardening
As the sun warms the land thoughts turn to gardening as well
as larger scale planting operations. This month Rural Voice
starts a gardening column which we hope will be a regular
feature.
Readers with gardening problems, or successes, are invited to
write to Rural Voice. Out gardening expert will attempt to help
solve readers' problems and we'll share readers' successes with
all Rural Voice readers. Send your gardening column
contribution to Rural Voice, Box 10, Blyth, today.
Cold frames give you a gardening head start
Home gardeners who want a head start
on the garden can capture the warm spring
sunshine, and put it to work in cold frames.
These large boxes, 45 to 60 cm high, are
set on top of the garden soil, and covered
with sheets of glass or plastic. The cold
frame acts as a greenhouse for the
seedlings planted inside, says Burke
McNeill, Ontario Ministry of Agriculture
and Food extension horticulturist.
If the cold frame is used before the
danger of severe frost is past, some source
of heating is necessary, he says. A small
portable heater provides sufficient heat,
but for permanent cold frames, electrical
soil heating cables are more practical.
For cold frames located in areas without
access to power, manure can be used to
warm the soil. Start by digging a pit 30 to
38 cm deep, and add 15 to 20 cm of fresh
manure. Cover the manure with 20 cm or
more topsoil.
"Make sure there is sufficient topsoil so
that the plant roots won't penetrate into
the manure." says Mr. McNeill.
The actual cold frame can be constructed
from old boards or cement blocks. The
sides are low and sloped slightly. so the
glass top will shed water. For best results,
Mr. McNeill recommends a slope of about
10 cm facing south.
"Storm windows make ideal tops for cold
frames," says Mr. McNeill. "On warm,
bright spring days, the top can be opened
slightly to let some cool air inside the
frame."
Vegetables, such as tomatoes, peppers
and cabbages, can be seeded directly into
the topsoil of the cold frame, and later
transplanted to the garden.
Help for the tree buyer
If you're planning to buy trees this
spring to landscape your home or provide
shade, Agriculture Canada has some
publications you might find useful.
The department's specialists have pre-
pared a checklist of ornamental trees for
Canada. And to go along with this list there
is a map of plant hardiness zones.
Many of the listed trees are widely
grown in Canada, while others are useful in
only some parts of the country because of
their hardiness or other special adaptive
features.
In selecting trees for any particular area,
hardiness is the most important factor to
consider. New trees or those unknown to a
gardener are a problem if their survival is
uncertain.
Many factors affect the hardiness of a
tree in a given area. The minimum
temperature in winter is the most import-
ant element in tree survival. Other factors
are the length of the frost -free period,
summer rainfall, soil type, moisture and
wind.
Soils, especially on the prairies, also
often critically influence tree survival. Soil
components can be amended to overcome a
difficulty with shrubs, but the quantity of
additives needed for trees is often too large
to be practical.
Low rainfall too, can be overcome by
irrigation, but this is often time consuming
or impossible for large trees. Very little can
be done to change the climate for tree
growth.
Agriculture Canada's tree list includes
57 varieties of maple, 50 types of crab
apple, 28 of cherry, 23 pines, 20 hawthorns
18 magnolias, 19 elms, 17 oaks and 14
willows.
The checklist is available in publication
1343, A Checklist of Ornamental Trees for
Canada, and the accompanying map is
publication 5063, Map of Plant Hardiness
Zones in Canada. Two other useful
publications are publication 994, Culture of
THE RURAL VOICE/MAY 1979 PG. 47