Callistephus chinensis 'Tower, Quartz Silver Rose'

Callistephus chinensis 'Tower, Quartz Silver Rose' is a very special variety. A stunning white summer aster with large double, peony-type blooms. Each petal is delicately frosted with silver-rose at the tips.
The amazing blooms have fully re-curved petals and grow up to 10cm (4in) wide. Each vigorous plant can produce as many as 10 to 15 stems, loaded with blooms they are perfect for flower arranging and for for wedding work.

The 'Tower' series is an excellent variety for commercial cultivation or simply for the cutting garden. Cut flowers last much longer than other varieties and just one plant is enough to create a bouquet.
Seeds can be sown at anytime from January to July for flowering through to October. From sowing to flowering takes 110 to 120 days. Flowering occurs in August-September, when the demand for bouquets is traditionally high.

Callistephus chinensis, commonly called the China Aster, is a popular and reliable annual that provides large 8 to 12cm (3 to 5in) diameter blooms from late June through to late October. The fast-growing plants, clad with ovate, toothed, medium green leaves, produce large, firework-like blooms in wonderful shades.
Blooming from late summer to well into autumn, Asters are easy and fast to grow and are quite irresistible to butterflies and bees. These fabulous flowers are invaluable for beds and borders,and make an excellent cut flower arrangements. The entire growing process from seedling to flower taking just 10 to 15 weeks to complete.
As cut flowers, China asters have rigid stems that are often 60 to 90cm (24 to 36in) tall, they hold long-lasting blossoms that don’t drop their petals. Asters bring liveliness and vibrancy to any flower arrangement, but they also shine brightly on their own, lasting up to ten days in the vase. Add them to large, mixed bouquets, or placing them in a tall vase on their own as a simple and happy floral piece.

Sowing:
Sow early indoors is recommended. Sow 6 to 8 weeks before the last frost date, or sow directly where they are to flower once the soil has warmed. For a continuous show, you may wish to plant stagger the sowing dates. The seed may also be direct sown in April to May where the plants are to flower, but in this case flowering will start later.
A sunny situation should be chosen for the aster bed, which should be prepared as soon as possible, making sure that drainage is good. The optimum temperature for germination is 21°C (70°F).
Pinching is not required. Heat and reduced daylength initiate flowering. Establish plantings early to avoid short stems.

Sowing Indoors: March to April
March and April sowing should be made in gentle heat, sowing into trays of compost. Just cover the seeds with a sprinkling of compost or vermiculite.
When large enough to handle, transplant seedlings into 7.5cm (3in) pots or trays. Handle the plants with care and avoid disturbing the roots as much as possible when transplanting to prevent wilting.
Gradually harden off for 10 to 14 days before transplanting into the flowering site in early May. Light spring frosts will not harm the plants. Plant 25 to 40cm (10 to 16in) apart.

Sowing Direct: May to June
Sow directly where the plants are to grow. Sow after your last frost date and when soil temperature is 18 to 21°C (65 to 70°F).
Sow thinly, 6mm (1/4in) deep in shallow drills. Sow 30cm (12in) apart in well-cultivated soil which has been raked to a fine tilth. Water ground regularly, especially in dry periods.
Outside sowings should be gradually thinned, to the same spacings when the seedlings are large enough to handle.

Cultivation:
Flowers should be removed as soon as they have faded to promote the growth of further blooms. Plants can be cut or pinched back in early summer to encourage a bushier, compact form and later flowers.
Never over water, but do not let the soil dry out. Preventive measures should be taken against aphids.
Plants should not be planted in the same ground two years in a row to avoid Fusarium Wilt. A soil-borne disease that has plagued Asters in the past.
Once established, liquid feed fortnightly. As they grow, taller plants may need support or staking.

Cut Flowers:
Asters have a long decorative life, usually 6 to 10 days but with flower food they are able to last up to two weeks.
Typically, annual Aster flowers are a strict late summer/early autumn variety, but with a carefully organised program, blooms are able to flourish year-round. They respond well to cool, coastal climates and are often grown in hoop houses, where they are protected by cold evenings, even during the colder months of winter. The entire growing process from seedling to flower takes approximately 10 to 15 weeks to complete.
Harvest of aster flowers can begin as the outer petals on the flowers begin to open, and can continue to be harvested when the blooms are fully open. The leaves often wilt before the flowers, so the leaves are best stripped off the lower half of the stem, before placing in water.
Place flower stems in a clean bucket of floral preservative / floral food or two hours before storage or usage, keep them treated during transport or storage. Cold store at 0 to 4°C (32 to 38°F) and recut stems as arranging if required.
Callistephus is very susceptible to bacterial contamination in the vase or storage water. It is very important to keep the leaves out of the water and to practice good sanitation. Change the water and clean the vase every third day.

Seed Saving:
Allow the flowers to mature into seed heads. The dried heads will contain tiny tan seeds of a rounded shape. Remove the heads and spread them out to dry completely, away from directed sunlight. Crush or open the heads to release the seed. Store the cleaned seed in a cool, dry place.

Origin:
Originally from China, this species has undergone much horticultural manipulation to achieve an array of cultivars. The species, or wild, form of China Aster is 75cm (2.5 feet) tall, with simple, single white to violet-blue flowers with yellow centres. Today's cultivated varieties vary in height from 20cm to 1m (8in to 3 feet) tall. The flower heads, up to 12cm (5in) across, are often totally composed of petallike ray flowers, and range in colour from white and pale yellow to pink, rose, red, blue, purple, and violet.
China Aster seeds were first sent to Paris from China in 1728 by a Jesuit priest. This showy annual flower was cultivated in America as early as 1737 by Williamsburg's John Custis and it grew in popularity in European gardens through the 18th century. By 1804 Bernard McMahon of Philadelphia was selling eleven cultivars of Aster chinensis in a variety of “sorts” including double and quilled forms.

Nomenclature:
Callistephus chinensis is pronounced ka-LIS-te-fus chin-EN-sis.
The genus name comes from the Greek words kalli meaning beautiful and stephos meaning a crown, in reference to the flower’s snugly packed, thickly fringed petals that surrounds its rich, golden yellow center which resembles a crown.
There is just the one species in the genus Callistephus. The specific epithet chinensis refers to the plants origin, the country China.
The name Aster comes from the Ancient Greek word astron which arrived through the Latin word astrum, meaning 'star', referring to the shape and colour of the flower head.