■ Site: free-draining soil in full sun.
■ Plants: choose few but many – restrict your palette. Plant tightly, 30cm apart, to create a herbaceous perennial bed that naturally suppresses weeds.
■ Structure first: select grasses that bring diversity of architecture, height, tone and texture; tall, airy Calamagrostis x acutiflora ‘Karl Foerster’, voluminous, mid-height Pennisetum villosum, shaggy tufted golden oats. Plant in threes at repeat intervals along the bed.
■ Generally, plant tall at the back, shorter at the front, but break the rule where it feels right.
■ Secondary plantings: to add interest interplant flowering plants in bold blocks or drifts, seven to 11 of each, colour-themed (blue and yellow). Blues: Iris ‘Sable’, Lavandula angustifolia ‘Hidcote’. Yellows: Kniphofia ‘Percy’s Pride’, Spiraea japonica ‘Goldflame’.
■ Book-end with contrasting, naturally domed,…