PLANT YOUR BORDER
Most of these plants intensely dislike winter cold and wet, so to keep them happy you’re after a well-drained soil in a sunny or, at most, semishaded site. You can improve heavier ground by adding lots of horticultural grit and garden compost, or even by building raised beds. An annual mulch of well-rotted organic matter helps to improve soil structure, keep on top of annual weeds and retain moisture over summer. Before you start planting, make sure the area is free from perennial weeds to avoid having to extract them from newly established plants later.
1 Start with the warmth lovers
Late spring is the ideal time to establish new kniphofias, penstemon and salvias, but you can continue to plant into summer as long as you keep an eye on watering. All three of these plants can struggle from an autumn planting if they don’t get established before the weather turns, so keep late purchases under cover in a cold frame or greenhouse and plant out the following spring.
Although kniphofias need good winter drainage, they also like moisture to thrive during the growing season – mulching around plants helps. Cut back old flower spikes once they have finished but leave the foliage over winter to add a little extra insulation, tidying away in spring to smarten things up. In time you can lift and divide large clumps as growth starts in spring. They look particularly good threaded through a sea of flowering grasses.
You should be able to pick up in-flower penstemon and salvias at plant nurseries now
and, as long as you keep deadheading and watering during dry spells, there’s no reason they won’t give you months of colour. Come autumn, leave the top growth in place for added winter protection, just reduce the height of the very longest shoots to minimise wind rock, then add a blanket of dry mulch around the plant. Only cut back to new shoots in late spring when the worst frosts have passed. You can propagate new penstemon by taking semi-ripe cuttings in late summer, overwintering them somewhere frost-free and planting out in late spring. Large clumps of salvia can be lifted and divided in mid spring.
2 Add the hemerocallis and achillea
These two golden-flowered herbaceous perennials add a glow to your border even on overcast days. If you’ve been put off by some of the chunkier daylilies in the past (they can be a little carthorse-like) then dainty lemon-yellow ‘Corky’ should change your mind. Both hemerocallis and achillea are best established in autumn or spring but you can get away with summer if you’re prepared to water often. In time they’ll grow to form generous clumps that can be lifted, divided and replanted to spread further sunshine around the garden.
Plant the achillea near the front of the border so you can see the multitudes of insects that inevitably turn up to feed on their nectar-rich flowers. Deadhead to keep the display going but leave later season heads intact to stand into winter. Like the sedum flowers below, they have a wonderful habit of catching little clouds of frost and snow.
If you have the energy, deadheading individual daylily flowers helps keep things neat. Try snapping them off when drifting around the garden with an early morning cuppa. In spring cut back old foliage and flowers of both plants, tidying them up just as the new shoots start to come through.
3 Finish with the sedum
The dark foliaged sedum adds a vital dash of colour that’s echoed in the purple penstemon behind. Establish new plants in autumn or spring (gardening friends might be willing to lift and split a clump or two). Unlike some sedums, ‘Matrona’ stands tall rather than flopping outwards. Let spent flowers stand all winter before finally cutting them back to the base in early spring, taking care to avoid damaging the emerging fleshy leaves.