Calgary Rose Society

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SOCIETY
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Contents
•
Acknowledgements...................................................................................................... iv
•
Dedications.................................................................................................................. vi
PART ONE y ROSE INFORMATION
1
Introduction.................................................................................................................... 1
2
History of the Calgary Rose Society...........................................................................3
3
Classification of Roses...................................................................................................5
4
Landscaping with Roses.............................................................................................. 15
5
Establishing a Rose Garden...................................................................................... 23
6
Maintaining a Rose Garden....................................................................................... 31
7
Winterizing a Rose Garden........................................................................................39
8
Growing Roses Organically........................................................................................47
9
Rose Garden Friends and Foes...................................................................................55
10
Diseases of Roses....................................................................................................... 63
11
Growing Roses in Containers.................................................................................... 67
12
Rose Propagation......................................................................................................... 71
13
The Rose Show............................................................................................................77
PART TWO y ROSE SELECTION
14
Favourite Hardy Roses................................................................................................85
15
Favourite Tender Roses.............................................................................................. 97
16
Award Winning Roses.............................................................................................. 127
PART THREE y REFERENCE
17
Glossary...................................................................................................................... 131
18
Appendix.................................................................................................................... 135
19
Index........................................................................................................................... 139
CONTENTS • v
7
Winterizing Roses
C
algary has great winters compared to the rest of
the Canadian prairies; they’re not too cold and we
can always count on a Chinook coming in a week
or two to warm us up. The bad news is that our winters are
not mild enough to grow some roses without protection from
the elements. As well, those warmer temperatures and dry
winds that the Chinooks bring can desiccate roses and other
garden plants. Protecting roses for the winter is an important
consideration for Calgarians.
The amount of winter protection needed depends on the
hardiness of any particular rose. We categorize roses as
Tender, which require ample winter protection, or Hardy, which
require little or no protection. Tender roses include Hybrid
Teas, English roses, Floribundas, Grandifloras, Miniatures and
any grafted roses. Climbing roses and Old Garden roses that
bloom on the previous year’s growth should also be considered
tender roses. Hardy roses include the Explorer roses, Morden
roses and some species roses. These roses only need winter
protection for the first year or two, until established.
The location of your rose beds and the health of the roses
will also determine the amount of winter protection needed.
Roses grown near the foundation of the house will need
less winter protection. Weak or unhealthy plants, tender or
hardy, may not survive Calgary’s winter no matter how much
winterizing is used. The maturity of each rose bush will also
control the amount of protection required; younger plants
require more winterizing as they are still getting established.
WINTERIZING ROSES • 39
64 • GROWING ROSES IN CALGARY
Powdery Mildew
description: Powdery mildew is caused by the fungus Sphaerotheca pannosa that lives
on the outer surfaces of leaves. The fungus sends little shoots into the cells of the leaf,
disfiguring and weakening the plant. The young leaves curl and twist as they develop, while
older leaves will show a white powdery dusting where the outbreak is severe.
Cloudy, humid weather with warm days and cool nights are ideal conditions for mildew to
become established. This is particularly true in Calgary where late afternoon showers and
cool nights are common. It takes 7 to 10 days from the time the mildew fungus lands on a
leaf for the symptoms to appear.
damage: Powdery mildew usually attacks the lower surface of the leaf first and then
appears on the top of the leaf. Infected flower buds become distorted as they open but
mature flowers are seldom affected.
control: To decrease the chances of mildew, plant disease resistant rose varieties.
Ensure that the roses have adequate ventilation. Plant roses in full sunlight and water
early in the day to ensure the leaves dry before nightfall. Avoid chemical fertilizers high
in nitrogen as these promote succulent growth that is susceptible to both disease and
insects. Feed the roses organically so they develop a thicker cuticle on leaf surfaces and are
therefore less susceptible to fungal disease.
To help control powdery mildew, prepare a solution of sodium or potassium bicarbonate
and insecticidal soap. Beginning as soon as rose buds appear in the spring, spray the plants
every 7 to 14 days. Spraying with a fungicide, milk or sulphur may also be effective. More
details are given in the previous feature on Powdery Mildew Control appearing before
chapter 10.
In the fall, pick up and prune out infected leaves before adding winter protection to
reduce the chances of powdery mildew spores over-wintering.
Black Spot
description: Black spot is a serious disease that affects many types of roses. It is caused
by the fungus Diplocarpon rosea which lives on rose leaves, in leaf litter and on infected
rose canes. The spores of the fungus are spread by wind or splashing water. The abundance
of black spot varies from year to year and is more common later in the summer. Black spot
appears as black circular spots that can grow up to 10 mm (½ in.) in diameter, usually during
periods of wet weather. The spores germinate when they have been wet for at least 7 hours
and the temperature is around 18˚–24˚C (65˚–75˚F).
damage: The lower leaves of a rose bush become infected first. The disease then spreads
to the entire plant causing yellowing of the leaves and defoliation. Black spot weakens the
plant and, if left unchecked, the plant may die.
control: Plant roses in locations that reduce favourable conditions for the development
of black spot. Ensure that there is adequate air circulation among the roses. The foliage
of roses planted in full sunlight will dry rapidly once wet. Avoid wetting the foliage when
watering roses, especially during dark, cloudy days. Plant black spot resistant varieties of
roses.
During the summer, infected leaves can be removed from the rose and from the soil
around the rose and discarded. Prune and discard any infected stems. A solution of sodium
or potassium bicarbonate can be used to spray the infected plants every 7 to 14 days. A
systemic fungicide can be used for extreme outbreaks. In the fall, pick up and prune out
infected leaves and stems before adding winter protection to reduce the chances of black spot
spores over-wintering.
120 • GROWING ROSES IN CALGARY
Rosa Mundi (R. gallica versicolor)
Gallica
Flower: While classified as a pink blend, the blooms on ‘Rosa Mundi’ are actually pink or
red and white striped. The small clusters of large, semi-double flowers come in one flush in
mid-summer. There is no repeat. Blooms are produced on old wood.
Fragrance: Moderate to strong.
Form & Foliage: ‘Rosa Mundi’ will grow to about 1 m (3 ft.) in height and 75 cm (2.5 ft.)
in width. If grown in shade, there is a reduction in bloom production. The plant is healthy
while in flower, but gets some mildew later and aphids seem to like it.
Winter protection: Semi-hardy. Some winter protection required. Canes should be
covered. Average rose to grow.
Comments: “Dip a blush pink rose in berry juice, then shake it and this is what you get.
Very interesting colour combination.” By far the most popular of the Gallica Roses, ‘Rosa
Mundi’ is about 300 years old.
Rosemary Harkness
Hybrid Tea
Flower: ‘Rosemary Harkness’ has medium sized, semi-double, orange pink blooms that
start high centered and open wide to reveal the stamens. Single blooms and small clusters
are spread all over the plant in a nearly continuous display.
Fragrance: Faint to moderate.
Form & Foliage: ‘Rosemary Harkness’ is bushy and grows to 1 m (3 ft.) in height and
60 cm (2 ft.) in width. The new red foliage and glossy dark green mature foliage are only
rarely bothered by black spot.
Winter protection: Full protection required. Easy rose to grow.
Comments: “Very pretty. Not a great producer.” “This rose is a good garden rose, but not
especially suited for a show rose.”
Royal William (Fragrant Charm, Duftzauber)
Hybrid Tea
Flower: ‘Royal William’ produces large, dark red, high centered blooms on individual
long stems. It is a very productive rose that blooms in flushes with only a short break
between.
Fragrance: Faint to moderate.
Form & Foliage: This is a sturdy bush that grows about 1 m (3 ft.) in height and 60
cm (2 ft.) in width. When grown in full sun, the foliage is glossy and only occasionally gets
mildew or black spot.
Winter protection: Full protection required. Easy rose to grow.
Comments: “Gorgeous red blooms.” ‘Royal William’ commemorates the arrival of King
William III in England in 1688.” It frequently wins ribbons at the Calgary Rose Show.
GAR004060 GARDENING / Flowers / Roses
GAR019010 GARDENING / Regional / Canada
C
algary has unique growing conditions that challenge
even the most experienced gardener. This book, by the
experts at the Calgary Rose Society, contains everything you
need to know about growing beautiful roses including:
y Advice on establishing, maintaining, and landscaping a
garden full of healthy roses in Calgary and the Chinook
country of Southern Alberta.
y Techniques for safeguarding your roses from winter weather.
y Nearly 300 colour photos and illustrations with 113 hardy
and tender Calgary rose favourites described in detail.
y Detailed descriptions and photos of the beneficial insects,
pests and the common diseases that may affect your roses.
y Seasonal schedules for fertilizing roses.
y A useful glossary, profiles of rose gardens around Alberta,
and both a subject and plant index.
“Growing Roses in Calgary is both thorough and complete.
Don’t grow roses in our crazy Calgary climate without this
gardener-driven, encouraging, and beautifully illustrated book!
Finally, Calgary rose growers have the full set of instructions
they need to succeed.”
$25.00
ISBN 978-0-9811347-0-3
Printed in Canada
Donna Balzer (BSc Agriculture) is a professional horticulturist,
Calgary garden writer, and broadcaster.