'“Giant Tetra Double” is a new compact Rudbeckia variety that produces masses of voluptuous, deep yellow, double flowers with a contrasting black central cone from early summer till frost.
The result of intense selection, this ‘double daisy' grows to around 75cm (30in) tall and yields a very high percentage of large 12 to 15 cm (5 to 6in) double golden yellow flowers. The abundant golden-yellow large blooms atop sturdy stems never flop.
Plant en mass, prairie style for a blaze of sunny colour, or in small groups in borders and beds, they make an excellent cut flower and are a great attraction to bees and butterflies.

Rudbeckia is ideal in sunny sites and blooms well in partial shade as long as it gets ample moisture and. Ideal for large groupings in summer; they are easy to grow in most garden soils and will tolerate heavy clay. Rudbeckia
Rudbeckia stand up well to wet weather and once established, are fairly drought tolerant, but they perform best with regular watering in soil that does not completely dry out.
Very easily propagated by seed, Rudbeckia are considered to be hardy and disease-free plants. The seedheads are attractive to birds, especially finches and add interest to the winter garden.

Sowing: Sow in late winter to late spring
Sow seeds directly where they are to flower two weeks before the last expected frosts in your area (usually around May) or give them a head start, planting indoors six to eight weeks before planting outdoors out.
The seeds need light to germinate, so just press them into the soil surface or use a little vermiculite - don't bury them.

Sowing Indoors: Late February to early April
Seeds are best sown indoors in pots or trays containing good seed compost. ‘Just cover’ the seed with vermiculite and place in a propagator or warm place maintaining an optimum temperature of 18 to 20°C (65 to 70°F) Keep the compost moist but not wet at all times. Germination should occur between 10 to15 days.
Thin to 7.5cm (3in) pots when seedlings have developed two proper leaves and are large enough to handle. Remember to handle the seedling by the leaves only, supporting the weight of the seedling under the roots as you transplant.
Grow on and harden off by gradually acclimating to outdoor conditions for 10 to 15 days before planting out into their permanent positions when temperatures start to rise.
Plants transplant well and should be spaced 30 to 45cm (12 to 15in) apart

Sowing Direct: Late April to early June
Sow thinly, 3mm (1/8in) deep in drills 30cm (12in) apart in well-cultivated soil which has been raked to a fine tilth. Water ground regularly, especially in dry periods. When large enough to handle, thin out seedlings so that they are finally 30 to 45cm (12 to 15in) apart .

Cultivation:
The trick with Rudbeckia is to make sure it goes in soil which does not bake dry or the whole plant will collapse. A semi-shady position will help if the soil does tend to dry out in summer, as will a thick mulch, applied after a night of heavy rain.
To extend flowering and prevent self-sowing, deadhead the spent flowers, this also makes for a tidier-looking plant. However, there are advantages if the old flowers are left alone, the cones have ornamental appeal after the petals have dropped, birds enjoy the seeds in the winter; and you will enjoy the benefits of seedlings next spring.

Plant Uses:
Cottage/Informal Garden, Flower Arranging, Pots and Containers, Flowers Borders and Beds. Prairie planting. Drought tolerant. Wildlife Gardens.

Origin:
These excellent herbaceous mostly perennial plants (some annual or biennial) are originally from the USA. They include around 20 species, with four varieties of Rudbeckia hirta:

• Rudbeckia hirta var. angustifolia. Southeastern United States (South Carolina to Texas).
• Rudbeckia hirta var. floridana. Florida, endemic.
• Rudbeckia hirta var. hirta. Northeastern United States (Maine to Alabama).
• Rudbeckia hirta var. pulcherrima. Widespread in most of North America (Newfoundland to British Columbia, south to Alabama and New Mexico; naturalised Washington to California).

Nomenclature:
The name was given by Carolus Linnaeus in honour of his teacher at Uppsala University in Sweden, Professor Olof Rudbeck the Younger (1660-1740), (aka Olaus Rudbeckius), and his father, Professor Olof Rudbeck the Elder (1630-1702), both of whom were botanists. It is pronounced rud-BEK-ee-a.
The species name hirta comes from the Latin hirsutus meaning ‘covered in hair’ and refers to the trichomes (hairs) occurring on leaves and stems.
Rudbeckia is one of at least four genera within the flowering plant family Asteraceae whose members are commonly known as coneflowers; the others are Echinacea, Dracopis and Ratibida.