RHODODENDRON & AZALEA INFORMATION
There are few shrubs which grow outside of the tropical zones that can match
the colour spectacle of Rhododendrons and Azaleas in full bloom. From white to
pink to purple to blue, as well as the yellow and oranges, their blooms run the
full colour spectrum. They are generally disease free and easy to grow.
They are generally unfavored by ungulates
and unsavored by slugs.
AZALEAS
Excellent as specimens or massed. Many have a delightful scent, and excellent fall foliage
colour. Extremely hardy and quite heat tolerant. Several hybrid groups have
developed, and if possible we have included the group in each individual
description. These categories are:
GHENT
(Gh) Small flowers, some scented. Growing 4-6' tall.
Hardy to -32C. Good autumn colour.
KNAPHILL/EXBURY
(Kn) or (Ex) The largest and brightest flowers. Some scented. Hardy to
-30C.
OCCIDENTALE
(Oc) Upright, tall plants (to 8'). Usually strongly scented.
NORTHERN
LIGHTS (NL) Produced by the University of Minnesota. Hardy down to -40C. Flower
buds can withstand temperatures of -40C without injury. Compact growing,
reaching 5-7' in height and spread. Small flowers in 3-4" wide clusters
from late May to early June. All are fragrant.
RHODODENDRONS
While generally known by their flowers,
unrecognized by non-rhododendron aficionados is the variety of leaves available.
There are 4" plants with 1/2" leaves, and 40' plants with 30"
leaves. Some are smooth, some are heavily textured, and some come covered in a
downy coat of coloured indumentum. While they tend to grow best in the
benevolent climate of the West Coast, there are hardy varieties that can thrive
in southern Ontario, Quebec and the Maritimes. Those of you in the Prairies
should try them with caution. They suffer most when the ground is frozen, the
air drying cold, and when exposed to the wind. Being evergreens, they can
dehydrate under these conditions. Those of you trying to grow varieties marginal
to your area should fertilize only in spring and restrict watering as much as
possible going into the fall.
The flowering season of Rhododendrons
extends from February to June on the West Coast and late March to July in the
East. We have indicated the sequence of flowering with the following codes: VE=Very Early, E=Early, EM=Early Medium, M=Medium, ML=Medium
Late, L=Late, VL=Very Late.
RHODO &
AZALEA CARE: Choose a site protected from drying winds and excessive direct
sunlight. Keep away from a building foundation, a roof overhang, or under trees
with dense shading or aggressive root systems.
Plant them in moist, well-drained acid soil.
Dig a hole large enough to accommodate the size of the root ball. Soak the root
ball in water if it seems dry before planting. Of utmost importance is to
plant them at the same level as they have been grown. Keep the top of the root
ball even with the ground surface. Soil mounding around their
stem is a certain recipe for disaster.
Pack the soil
lightly and water in. A mulch of bark or decomposed sawdust will keep weeds down
and hold in moisture. Never hoe or cultivate around the surface roots of these
plants.
Apply an acid
fertilizer twice yearly on young plants - just before and just after flowering.
Older plants do not need fertilizer unless the foliage shows a deficiency or the
plant is not flowering well.
Pinching the
single terminal shoot just as it starts in early spring will encourage branching
and produce a more compact plant.
The Plant Farm - 177 Vesuvius Bay Road, Salt Spring Island, BC V8K 1K3
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