Introduced from Australia in 1828, Didiscus caerulea, also known as Trachymene coerulea belongs to a broad genus of annuals or semi-perennials and is known as the Blue Lace Flower for the unusual pale lavender-blue flower colour of the species. Each delicate lacy umbel shaped flower head is composed of tiny, star-shaped, sweetly fragrant flowers. Recent developments have broadened the range, with Pink and White forms now available.
Perfect for the cutting garden and a lovely summer bedding plant, Didiscus are suitable for country cottage style or contemporary arrangements, the flat-topped flower clusters resemble the frothy flowers of Queen Anne’s Lace. The plants grow to a height of around 60 to 70cm (24 to 30in), the graceful large flower heads grow to around 8cm (3in) across and mix easily with others in the garden or bouquet.
Didiscus caerulea 'Blue Lace Flower' is easily grown from seed in any rich soil in full sun, sown March to April for flowering in July to August. The plants bloom within 14 weeks from sowing and continue to bloom for a remarkably long period. Regular deadheading will extend the season.
The sweetly scented lavender-blue flowers can be cut and brought indoors. They will last around 7 to 10 days in a vase.
Sowing: Sow indoors March to April for flowering in July to August.
Seeds may be started early indoors 6 to 8 weeks before frost-free weather. Alternatively, sow seeds directly outdoors where they are to grow after all danger of frost is past and the soil has warmed. The plants can also remain in a greenhouse. Indoors or out, make sure seeds are fully covered as they need darkness to germinate.
The plants take approximately 110 to 120 days to mature and bloom
Sow indoors 6 to 8 weeks before last frost at temperatures of around 18 to 20°C. (65 to 70°F).
Sow seed into seed trays or small pots and lightly cover with a thin layer of compost. Keep under cover. Water carefully from the base of the tray. Germination usually takes around 15 to 20 days.
Transplant when there are at least two sets of true leaves and seedlings are large enough to handle. Be very careful as the plants resent being disturbed. Prick out into small pots and grow on.
Transplant to the garden after the last freezing nights usually around mid May. ‘Harden off’ for 3 to 4 days before planting out.
Sow where they are to flower once temperatures reach 15 to 20°C (59 to 68°F). Surface sow to no more than 1mm (1/8in) deep. Sow thinly in drills 30cm (12in) apart in well-cultivated soil which has been raked to a fine tilth. Lightly cover seed
Water ground regularly, especially in dry periods. Germination will normally occur within 21 days at temperatures around 68 to 72°F (20 to 22°C). When large enough to handle, thin out seedlings to 20 to 30cm (8 to 12in) apart.
When Didiscus are grown for cut flowers in a greenhouse, they should be planted in 5 or 6-inch pots or in benches, 6 to 8 inches apart. Take care in watering until they are established in their final pots, as the soil must be kept moist.
Didiscus are very tolerant of heat, humidity, drought, exposure, wind, pests, and diseases.
Choose a sunny, well drained site. In very hot climates they would benefit from a little shade.
Plant 20 to 30cm (6 to 8in) apart. Use thin sticks to support the stems.
Cut the flowers in the morning when approximately 80% of the flowers are open.
For dried flowers, air dry flowers for two to three weeks in a dark, dry place. Darkness is necessary so the flowers do not turn brown.
Beds and borders, City, Cottage/Informal, Flower Arranging, Low Maintenance, Wildlife
Didiscus, also known as Trachymene is a genus of herbs in the family Araliaceae. The species are native to south western Australia, Malaysia, New Caledonia and Fiji. It can be found in dryish or sandy soils in shrub lands and grasslands.
The Trachymene genus has had several re-classifications in recent years and when I first came across these plants, they were sensibly placed in the family Umbelliferae as their flowers are grouped together in umbels, which was fine as it was easy to remember and contained all the then known species. Later it was placed into the Apiaceae family, which although more difficult to remember, still contained all species. However now it has finally come to rest in the Araliaceae family, which I find not only more difficult to remember, but it contains only some of the original genera.
The genus name Didiscus derives from the disc shaped flowers
It is also known as Trachymene, the name is taken from the Greek trachys meaning ‘rough’ and mene meaning ‘moon’ referring to the rounded shape of the umbels
The species name caerulea, or sometimes caeruleus, is occasionally found with the older spelling coerulea or coeruleus. All these simply mean ‘blue’ and refer to the colour of the blooms of the species plant.
It is commonly called the Blue Lace flower and can often be found marketed under the name of 'Lacy Blue'
- Additional Information
Packet Size 260mg Average Seed Count 100 Seeds Family Araliaceae Genus Didiscus Species caerulea Synonym Trachymene coerulea, Didiscus coerulea, Didiscus rosea Common Name Marketed as 'Lacy Blue' Hardiness Hardy Annual Flowers Lavender Blue Natural Flower Time June to September Height 60 to 70cm (24 to 30in) Position Full sun for best flowering Soil Moist, well-drained, fertile soil is best.