Dahlias in the Garden
As tender bulbs, dahlias cannot be planted
outdoors until threat of frost has passed. They can either be
started up indoors in pots in late winter/early spring then planted
outdoors, or, planted outside right into the garden or large
containers, around "Planting Time".
Set tubers horizontally beneath 8 cm of prepared
soil. As shoots grow, fill in with 2 to 8 cm more soil. For large
growing varieties, you might like to set stakes in place at planting
time in order to avoid damaging the roots when staking later in the
Dahlias can also be purchased as bedding plants.
Increasingly, garden centres are offering these and other
sought-after summer bulbs in this already-started condition.
The full range of dahlias make excellent
container plants and are perfect for bed, border or cutting garden.
Dahlias are also wonderful as cut flowers, with a vase life of up to
a week. The added bonus being, the more you cut and pinch dahlias,
the more flowers they produce.
Dahlias need to be watered regularly and will
benefit from being fed with a low-nitrogen fertilizer during the
growing season. Pinching off or cutting spent flowers is
recommended. The stalks are woody, so aphids can attack them. A
spray with insecticidal soap or even physically washing the aphids
have been successfully bred over the centuries that, today, they are
divided into many
groups. Following are the
groups with importance to home gardeners:
Cactus and Semi-Cactus
Both types have fully double
flowers with long pointed ray-like petals that revolute or roll back
along about half their length, giving the flowers a spiky look. Most
cultivars reach a high of more than a metre. Among the most popular
are: ‘Alfred Grille’ (salmon pink with a yellow centre), ‘Purple
Gem’ (cyclamen purple), ‘Ludwig Hellfret’ (bronze), ‘My Love’
(creamy white), ‘Kennemerland’ (yellow), ‘Firebird’ (yellow
with red tips).
These are fully double dahlias with broad,
flat-tipped petals that are sometimes wavy. The flowers are normally
large and the plants easily exceed a metre in height, though there
are even taller varieties. Cultivars to watch for include: ‘Duet’
(red with white tips), ‘Lucky Number’ (lilac-purple), ‘Berliner
Kleene’ (old rose), ‘Rosella’ (purple), ‘Seattle’ (yellow
with white tips), ‘Snowstorm’ (white) and ‘Golden Emblem’