Microsoft word - zz320 rudbeckia n.doc

Cultural Details: Rudbeckia
There are two classes of Rudbeckia, or ‘Black-eyed Susan’ – annual bedding types
and and perennial border varieties, which will be dealt with separately here. We also
include the Purple Coneflower, Echinacea purpurea, as a perennial type.
ANNUAL VARIETIES

Annual Rudbeckias make excellent bedding plants, particularly later in the year, with
their bright golden flowers and contrasting centres. There has been much breeding
work recently, and a large range of varieties is now available.
Some growers, having tried Rudbeckias, have been discouraged by the high level of
plants dying off during production. This problem can be minimised with good
attention to glasshouse hygiene.

Variety Selection

Compact types such as Toto and Becky make excellent pot bedding items in full
flower. Taller types like Prarie Sun reach a height of around 80cm, for tall informal
bedding displays. Check the catalogue for the full selection.
Programming

Sow mid February to April, for sale from mid-May to late Summer. (Rudbeckias
need long days to initiate flowering, so for very early flowering, supplementary lights
would be required to increase the daylength to 14 hours.)

Propagation and Growing on

Sow the small seeds (2,000 per gram) onto the surface of a free-draining, open, seed
sowing compost, which should be thoroughly wetted with a suitable fungicide prior to
sowing (to prevent damping-off diseases), and the trays allowed to drain. Ideally, sow
into plug trays to minimise root disturbance. Cover seeds with a thin layer of
vermiculite, and cover trays with clear or milky polythene to maintain humidity, until
the first seedlings are visible. Germination takes around 7-10 days at 20-22 oC. Keep
the germinating seedlings moist at all times, without overwatering, and grow on at 18-
20oC, shading as necessary.
When large enough to handle, after around 4 weeks, move the plants into a 4-pack or
11cm pot, using a standard potting compost. Commence liquid feed programme as
soon as plants are established in the pot. Grow at 15-18oC days down to 10-12 oC
nights, shading where necessary. If required, plants can be moved into a larger, 1-litre
pot, for a premium pot bedding product in flower. Use a well-balanced liquid feed
programme as soon as plants are established in the pack/pot (i.e. roots visible at the
base of the container).

Pest and Disease

Maintain good air movement through the crop, and water in the morning rather than
the evening to keep the foliage dry and lessen attack by Botrytis. Pay good attention
to glasshouse hygiene, using only fresh trays, pots, compost, water and clean bench
tops to avoid damping-off diseases and die back which is generally caused by
Verticillium. Check for the presence of pests such as aphids and whitefly, spraying
accordingly.
PERENNIAL VARIETIES

Perennial Rudbeckias make excellent late-flowering border perennials – Goldsturm is
the standard yellow variety, but we also have the black & green ‘flowered’ variety
occidentalis Green Wizard which is used in flower arrangements, and we list
Echinacea purpurea (purple coneflower) and White Swan also under Rudbeckia, both
attractive border perennials.
Programming

See below.

Propagation and Growing on

Sow the small seeds (1,200 per gram) onto the surface of a free-draining, open, seed
sowing compost, which should be thoroughly wetted with a suitable fungicide prior to
sowing (to prevent damping-off diseases), and the trays allowed to drain. Cover seeds
with a thin layer of vermiculite.
These perennial Rudbeckias require cold treatment for germination. Ideally sow into
trays March-June for 2 weeks, then into a refrigerator for 3-4 weeks at 5 oC , then
back out to around 20-22 oC to complete the process. Echinacea will in fact give
some germination without the cold treatment, but not as much.
When large enough to handle, move the plants into a large-celled plug tray, using a
standard potting compost, then on into an 8-9cm pot.
Cool the plants down in the Autumn, overwintered plants should be kept on the dry
side, under protection, such as a well-ventilated polytunnel or glasshouse. Sell as
green plants with a colour label, in Spring or Autumn. Overwintered plants can be
moved on into a larger, 2 litre pot when growth recommences in spring. Use a liquid
feed programme throughout culture during active growth phases.
Pest and Disease

Maintain good air movement through the crop, and water in the morning rather than
the evening to keep the foliage dry and lessen attack by Botrytis. Pay good attention
to glasshouse hygiene, using only fresh trays, pots, compost, water and clean bench
tops to avoid damping-off diseases and die back which is generally caused by
Verticillium Check for the presence of pests such as aphids and whitefly, spraying
accordingly. In fact in general, Perennial Rudbeckias should suffer few pest and
disease problems.

Information provided for guidance only, as cultural practices and climatic
circumstances vary.

Source: http://www.molesseeds.co.uk/flower_and_vegetable_seed_store_uk/zz320_rudbeckia.pdf