When to plant Wandflower 'Whirling Butterflies'?
Best month and method — Gaura lindheimeri 'Whirling Butterflies'
Plant your wandflower 'Whirling Butterflies' in March, April, May, September and October — the optimal month is usually May.
You're in the planting season right now — a good moment to start.

Spacing
45 cm
≈ 5 plants
For an X m² border, calculate: X × 5 plants.
Step by step: plant wandflower 'Whirling Butterflies'
Gaura lindheimeri 'Whirling Butterflies' thrives in full sun but tolerates partial shade, though flowering will be less prolific in shadier spots. Choose a well-drained position; this plant is particularly suited to sandy soil or loam and will sulk or rot in heavy, waterlogged ground. If your soil is clay-based, work in plenty of grit or sharp sand before planting to improve drainage. Plant container-grown gaura in March, April or May for establishment before summer, or in September and October while the soil is still warm. Dig a hole slightly larger than the root ball and loosen the soil at the base to encourage roots to spread. Set the plant at the same depth it sat in its pot—burying the crown too deeply invites rot. Space plants 45 cm apart to allow for their airy, spreading habit. After planting, water in thoroughly to settle the soil around the roots, then water sparingly. Gaura is drought-tolerant once established and resents sitting in wet soil. A light mulch of gravel or grit around the base helps keep the crown dry and suppresses weeds, but avoid organic mulches that hold moisture against the stems. Staking is rarely necessary despite the height; the wiry stems are surprisingly sturdy. In exposed gardens, however, a few pea sticks pushed in early in the season can provide discreet support. Gaura establishes quickly in the right conditions and will begin its long flowering season from late spring onward, with delicate white or pink blooms that flutter above narrow foliage like a cloud of butterflies.