PLANT YOUR BORDER
All these plants prefer full sun or at most part shade and a moist but welldrained soil. The iris and symphyotrichum in particular appreciate more moisture at their feet.
Add plenty of well-rotted compost or manure across the area, and to each planting hole. If you garden on heavy clay, try raised beds and add horticultural grit as well as compost. After planting, mulch the entire area with compost and renew annually in late winter to early spring.
1 Get planting
Most of these plants should be available as container-grown specimens at your local plant nursery this spring.
Give the miscanthus plenty of elbow room in its back-of-border position so its arching foliage isn’t crowded and ensure the artemisia leaves aren’t overshadowed.
The phlomis and symphyotrichum work best in generous numbers. Thread a sweep of phlomis across the border, its low mounds of foliage and narrow stems mean it can be brought to the front of the planting while still allowing a view through.
Establish the Michaelmas daisy in a cluster of three or five plants for really eye-popping autumn colour. They can be prone to powdery mildew, so minimise problems by ensuring plants aren’t too dry and stressed. Cut back and carefully clear away diseased foliage, or leave plants to continue
flowering if the infection is only mild, clearing away afterwards.
Iris sibirica also look especially good grown en masse. They can be bought as containergrown plants but if you order online they’ll probably be delivered as bare root rhizomes. On arrival, soak the rhizomes in water for an hour before planting around 5cm (2in) deep so the soil just covers the rhizome. Keep them moist while they get established. If the ground is frozen, pot up into containers and stand in a cold frame or sheltered spot, planting out once conditions improve.
2 Keep the display going
Pinch out the shoot tips of young artemisia in summer to encourage thick bushy growth. Spring is also the time to prune back established plants.
Rather than regular deadheading and having an autumn cut back, let the border stand for as long as the plants and weather allows. Not only do you get to appreciate its winter structure but also local wildlife will thank you for a hands-off approach. As things start to capsize, gradually clear away stems to the compost heap, or leave them to lie unobtrusively on the ground.
In spring, cut back the miscanthus to ground level and clear away any remaining old stems while you apply a new mulch.
3 Make more plants
The phlomis will gently self-sow or you can collect seed and sow in seed trays. Overwinter in an unheated greenhouse or cold frame, prick out seedlings in spring and grow on before planting out in summer. Divide Michaelmas daisies every three years. As new shoots appear in spring, lift and slice the clump into vigorous outer segments with a spade.
Miscanthus sinensis can be divided in spring just as growth begins. Lever out the clump and split with a sharp knife.
Divide established clumps of Siberian iris after flowering. Lift the whole clump then split into smaller hand-span clusters. Cut back foliage to a short fan and replant into soil with added compost. Keep reliably moist while plants put down roots. Take semi-ripe artemisia cuttings in late summer. Use shoots of this year’s growth that have begun to harden at the base. Insert into a 50:50 sharp sand/potting compost mix and keep moist until rooted. ✿