Agriculture Reference
In-Depth Information
By this process consumers are able to buy plants in full flower and enjoy these as
potted indoor plants over the Christmas season.
For other plants the process is less complicated as production is completed within
one year as in the case of annuals such as pansies. The plants are propagated from seed
in April to May, and the seedlings potted on the heated greenhouse until June to July.
The seedlings are then either planted up outside for a display, held in the greenhouse
or moved back into the greenhouse in August to September to flower and to be sold.
Cut flowers
In recent years a number of native Australian warm temperate cut
flowers have been introduced into Europe and the US and include examples such
as pink mulla mulla (
Ptilotus exaltatus
) which has large tapered pink-mauve flower
spikes and is used as a bedding plant, pot plant and cut flower (von Hentig 1985)
in Europe. Ptilotus “Joey®” was released by the German seed breeding company
Benary (Degraaf
2008
) onto the European market.
Ptilotus
species originate from
the central Australian desert and north-west Western Australia and have been suc-
cessfully grown in Europe by carefully adapting their production schedule to the
different conditions. As such they will crop within approximately 12 to 16 weeks
from sowing (Degraaf
2008
). To achieve a summer flowering target of June through
to August seed is sown and grown at 21°C in April of the same year for pot plants
(Fig.
12.10a
) or in November of the previous year for cut flowers (Fig.
12.10b
)
when grown under greenhouse growing conditions. Supplementary lighting may
need to be applied in winter to extend day length and surface heating applied to
22°C to encourage growth in central Europe. These plants are ready for pricking
out and potting on into large pots and then planted out for a summer flowering (von
Hentig et al.
1995
)
Introduction of warm temperate plants to Europe
In recent years the introduction
of ornamentals into Europe has to be planned and scheduled with precision. Most
young or emerging plant companies in Central Europe undertake extensive breed-
ing and testing to avoid negative feedback from their customers. Two world-wide
examples of the extent of this planning shows on the development of vegetative
propagated petunias and verbenas, as well as angelonia (
Angelonia angustifolia
).
The numbers of these new species and hybrids became so vast in the 1990s that
the Chamber of Agriculture in Germany advised customers on how plants could be
arranged and managed on balconies. A concept involved horticultural companies
providing their colleagues with early planted balconies of these species to demon-
strate to the customers how their balcony plants could provide early flowering after
the summer holidays. Similarly, several companies dealing with young plants took
the innovative step of looking for perennials and small shrubs, where the leaves
have a decorative value (variegated and coloured), and put them together in series
for autumn plantings. Plants with berries and late flowering species have been added
as well as grasses. The early flowering cultivars of Christmas rose (
Helleborus
niger
) and the eastern teaberry (
Gaultheria procumbens
) have become popular for
autumn production over the last two decades. These plants also offer the producer a
saving in heating costs. To extend the bedding plant season in Europe, a number of
plants for late winter and early spring have been tested and introduced into the mar-
