Sow the seed thinly on the surface of lightly firmed, moist seed compost in pots, cells or trays. Just cover with a light sprinkling of compost or vermiculite. Do not exclude light as the seeds need light to germinate.
Keep at a temperature of between 20 to 25°C (70 to 75°F). Keep the compost moist but not waterlogged; water from beneath the tray. Most seeds germinate between 21 to 30 days; some may take a little longer.
When large enough to handle, usually 4 to 6 weeks after germination, transplant seedlings into 7.5cm (3in) pots. At transplanting stage, the plant can be cut back, to encourage a more compact, bushy plant. Gradually acclimatise to outdoor conditions for 10 to 15 days before planting out after all risk of frost, 40cm (16in) apart. Plant in ordinary garden soil in full sun.
Germination time: 2 to 4 weeks. Temperature: 60 to 75°F (15—24°C). Start off eight weeks to two months in advance. Transplant outdoors before the last frost or at the beginning of autumn. Spacing 12 to 24 inches (30—60 cm).
Obedient plant combines well with the blue flowers of the late summer garden, like Caryopteris, Russian sage, and Catmint. The spiky flowers are also a nice contract with asters, sedum, and coneflowers. #companionplanting
I gotta say this plant is anything but obedient... when I grew this in Tx, it took over my entire plant bed, each winter it would send roots under ground that spread like fire, in the spring new plants would pop up every where, almost choking out all my other plants, it is very drought and sun tolerant. I would not have this plant in my garden again, unless it was in a pot!