Quick fixes for better borders now
Plant ready-grown flowering bulbs like Nerine bowdenii, which has elegant pink blooms.
Add grasses with autumn tints, such as Panicum virgatum ‘Shenandoah’ and Carex testacea.
Lift and divide perennials that look tired or overgrown.
Deadhead the likes of dahlias and penstemons to prolong flowering.
Clear leaves and cut back spent perennials, but leave attractive seedheads.