When to plant Pincushion flower 'Butterfly Blue'?

Scabiosa columbaria 'Butterfly Blue' thrives in full sun but tolerates partial shade, though flowering will be most prolific in a sunny spot. It adapts to a wide range of soils—loam, chalky, or sandy—provided drainage is good. Heavy clay should be improved with grit or sharp sand before planting, as waterlogged roots in winter can prove fatal. Plant in March, April, or May for establishment before summer, or in September and October to take advantage of warm soil and autumn rain. Space plants 30 cm apart to allow air circulation and room for the clumps to fill out. Dig a hole slightly larger than the root ball, loosen the soil at the base, and set the crown at the same level it sat in the pot—burying it too deeply encourages rot. Firm the soil gently around the roots and water in thoroughly to settle the plant and eliminate air pockets. A light mulch of garden compost or well-rotted manure around (but not touching) the crown helps retain moisture and suppress weeds during establishment. Avoid rich, heavy feeding at planting time; scabious prefers lean to moderately fertile conditions and can become floppy in overly rich soil. Water regularly for the first few weeks if rain is scarce, especially for spring plantings facing a dry summer. Once established, 'Butterfly Blue' is fairly drought-tolerant. If planting in autumn, little watering is usually needed unless the season is exceptionally dry. Staking is not required; the compact habit and wiry stems are self-supporting even in exposed sites.