Although
this site contains a lot of technical information I felt that
not everyone would be interested in growing dahlias for the show
bench and so I condensed the whole site into this one page.Although
this site contains a lot of technical information I felt that
not everyone would be interested in growing dahlias for the show
bench and so I condensed the whole site into this one page.
The most important thing to remember about dahlias is that they are about 90% water and are therefore easily damaged by frost. When contemplating growing a few dahlias in the back garden consideration has to be given to the area where you live and when the last frosts occur. Here in central Scotland it was the norm to plant out the first week in June but these past four years there has been frost in the middle of June and during 1999 frost occurred in the middle of August this caused havoc with my dahlias. It might be a good idea to consider having some protection such as old sheets or polythene that could be thrown over the dahlia plants at short notice.
The area for your dahlias should be dug
over and manured in the autumn. Fertiliser such as Growmore, Vitax
Q4 is applied at the rate of 3 to 4 ounces per square yard, two
weeks before planting.
Dahlia Plants V tubers
Dahlias are sold either as tubers
or as plants. Tubers are obtainable from garden centres
from about April/May. If you have a heated greenhouse you
can take delivery of mini plants from April onwards. On
arrival the dahlia plants should be potted on into 4 or 5 inch
pots taking care to shade them from direct sun for the first few
days. Grow on being careful not to over water in the early stages.
Dahlias potted in April may require to be potted on again to keep
them growing on strongly prior to planting. Pot grown dahlias
are available from mid May onwards and these can be grown on in
a cold greenhouse or cold frame until planting time. For
sources of dahlia plants and tubers see index. Personally I would
not recommend a novice grower to purchase tubers, plants although
needing extra attention when young will in my opinion give the
grower a guarantee of blooms to come.
SPACING For Dahlias
Plant firmly after thoroughly watering the plants leaving a slight
depression to help direct future watering towards the roots. Stake
and tie as soon as possible after planting. Plant 20 inches x
20 inches apart with a space for a path of about 3 feet. Lilliput
dahlias should be planted 12 to 15 inches apart, they will quickly
fill the allotted space and in no time will meet each other covering
the ground with a blanket of colour. This spacing should allow
plenty of room for development and adequate access for attending
to the plants as they grow.
STOPPING Dahlias
Plants should be "stopped" once established by removing
the growing tip. Mid June or early July is the time to stop, leaving
it too late will mean that the plants will flower later. If too
many stems are produced then carefully select the strongest stems
and remove all the weak ones (laterals).
GROWING ON AND FEEDING
DAHLIAS
Be sure to water during hot dry conditions, preferably in the
evening, and apply a recommended balanced fertiliser such as Chempak
No 3 and in August change to Chempak No 4. Potash is applied in
early August to add colour and firmness to the flowers and will
also help the production of tubers.
DAHLIA PESTS
Greenfly, caterpillars, earwigs, slugs and thrips all love to
chew and nibble at dahlias. General purpose sprays such as Sybol
or Tumblebug will help control these pest when applied regularly
(weekly).
DISBUDDING
DAHLIAS
Disbudding should commence as soon as shoots develop on leaf axils.
Remove the two little buds either side of the main bud (crown
bud) and remove the side buds/shoots at the next lower pair of
leafs and again at the next lower pair. This will force the plant
to concentrate all its energy into the remaining crown bud. The
number of growths retained or removed will influence the ultimate
size of blooms.
DAHLIAS FOR GARDEN DISPLAY
Instead of disbudding, allow plants to grow with all shoots intact.
As each terminal bud develops, flowers and fades, remove it to
allow the side buds to develop and flower. Continue removing old
flowers throughout the season. With such treatment, long lasting
colourful Dahlia borders can be created by grading varieties according
to height, but incorporating your own colour scheme. Further impact
can be made by using the vast diversity of form that dahlias provide.
LIFTING AND STORAGE OF
DAHLIA TUBERS
Throughout the summer the dahlia has not only been producing flowers
it has been producing tubers under the soil. These tubers can
be lifted and stored for the following year but dahlias are notoriously
difficult to keep and I recommend a novice should buy new plants
rather that depend on stored tubers. However it is worth a try
nonetheless. After the first frost, Dahlias should be carefully
lifted, all fibrous roots removed, and stems cut down to within
about two inches of the tubers. The tubers should be carefully
dried off and treated with a fungicide. Label each tuber as you
lift them. When dry and treated, store in a frost proof place
until required for propagation or planting out the following season.
Check periodically whilst in store for dampness on tubers and
stem which will lead to rotting of the tuber.