PLANT YOUR BORDER
Most of these herbaceous perennials prefer moist but well-drained soil that doesn’t dry out in the growing season. The exception is the verbascum, which is happiest in poor, free-draining soil, so lighten its planting site with extra grit.
Before planting, weed the site and add plenty of well-rotted organic matter to improve soil structure and fertility.
An annual mulch of weed-free compost helps keep on top of weeds and conserves moisture.
Start with the peony
If you don’t want to wait until bareroot season (autumn), buy a containergrown plant, but take care not to bury it too deeply when planting. Keep the crown free of mulch and aim for the growing buds to be no more than 5cm (2in) below the soil surface, preferably less. The brittle roots break easily, so handle plants gently. Plants established in late spring need watering during dry spells in their first summer.
Peonies prefer sunshine and good drainage without being smothered by neighbouring plants, so give them plenty of space to grow into. Large established plants can be lifted and split once foliage has died back in autumn, making sure each section has some roots and at least three plump buds. They’ll take a couple of years to settle before they flower again but careful shallow planting helps minimise this delay. Add hoops or other plant supports at the same time as staking the lupin (below).
Establish the lupin, cirsium and astrantia
Lupins are surprisingly unfussy about soil – just avoid prolonged winter wet. Insert low plant supports as they grow, using higher ones on more exposed sites. Protect new shoots against slugs and snails and if you find clusters of aphids, rub them off gently or use a jet of water. Cut back spent flower spikes and water deeply in summer dry spells to encourage more flowers.
Plant cirsium thistles in spring or autumn, taking care not to bury their low rosette of leaves. Improve the soil around their planting site with well-rotted organic matter to help them hold onto soil moisture; these plants love damp, fertile conditions. Deadhead to promote flowering and divide established plants in autumn or spring.
Astrantias are best positioned towards the front of this border so they won’t be lost behind taller plants. Like the cirsium, they need humus-rich soil that’s reliably moist over summer, so be sure to improve their planting hole. Cut back the first flush of flowers to prolong the display. Established plants can be divided in autumn or spring.
Give the verbascum a gritty start
Dusky red verbascum ‘Cherry Helen’ echoes the lupin spires beautifully. This short-lived perennial does best in full sun and well-drained soil; good drainage is absolutely essential if they’re to come back to life in spring, so add grit and compost when planting. Establish plants in spring to avoid winter wet and beware smothering the low leaf rosettes. Deadhead to keep the flowers coming and pick off brightly coloured mullein moth caterpillars as you see them. A protective mulch around but not over plants can help winter survival rates. You can also propagate new plants by taking root cuttings in very early spring.
Sow the aquilegia
Thanks to its black flowers and unusually tall stems, ‘Black Barlow’ is particularly ravishing and makes excellent cut flowers too. Buy young plants in late spring or surface sow onto seed compost, cold stratifying them in the fridge for four weeks if they’re reluctant to germinate. These plants don’t tend to be that long lived, but fortunately they self-sow, giving a crop of youngsters ready to take their place. ✿