Agapanthus ‘Jack’s Blue’ (African lily) £9.99
Position: full sun Soil: fertile, moist, well-drained soil (or John Innes no. 3 compost for containers) Rate of growth: average Flowering period: July to September Hardiness: borderline hardy (may need protection in winter) Deep purple buds form in loose clusters on the upright stems, and open to rich purple-blue trumpets that herald high summer. A tall evergreen form, it has an impressive silhouette and will look sublime in a pot. Offering a long period of interest with its flowers, decorative seedheads and year-round foliage, this is a beautiful plant that will also help add structure and height to sunny borders. Garden care: Keep well-watered during the growing season, applying a balanced liquid fertiliser each month from spring until the plant flowers. In cold, exposed areas protect the crown of the plant with a deep, dry winter mulch.

Agapanthus ‘Loch Hope’ (African lily) £9.99
Position: full sun Soil: fertile, moist, well-drained soil (or John Innes no. 3 compost for containers) Rate of growth: average Flowering period: July to September Hardiness: borderline hardy (may need protection in winter) Clumps of strap-shaped grey-green foliage are topped with impressive clusters of deep blue trumpet-like blooms from midsummer to autumn. This towering hybrid form was raised at the Crown Estate in Windsor and is suitable for sunny borders and patio pots. It is also tolerant of salt-laden air, so will flourish in coastal settings. Garden care: Keep well-watered during the growing season, applying a balanced liquid fertiliser each month from spring until the plant flowers. In cold, exposed areas protect the crown of the plant with a deep, dry winter mulch.

Deschampsia cespitosa ‘Goldschleier’ (tufted hair grass) £9.99
Position: full sun or partial shade Soil: dry to moist, neutral to acid soil Rate of growth: average to fast-growing Flowering period: June to August Flower colour: bright silvery yellow Hardiness: fully hardy A beautiful tuft-forming, evergreen grass that will help add structure and movement to the border. In summer the dark green leaves are topped with airy flower spikelets that turn a bright silvery yellow as they age. This airy grass looks lovely in a mixed border where it will waft hazily in the breeze. Relatively compact and easy-to-grow, it will flourish in neutral to acidic soil. Garden care: Remove the faded flower-heads in late winter before new growth appears. In warm areas the plant has a tendency to self-seed freely. Where this is the case remove unwanted seedlings as part of routine border maintenance.

Phlox paniculata ‘Discovery’ (phlox) £8.99
Position: full sun or partial shade Soil: fertile, moist soil Rate of growth: fast-growing Flowering period: July to October Hardiness: fully hardy For several months from midsummer, this beautiful oerennial is laden with domed clusters of pale pink blooms, each with a darker pink eye. Their scent is divine – good enough to stop you in your tracks – so if possible plant it near a pathway, door (or even better) a seating area to take full advantage. Garden care: Support with bamboo canes, brushwood or ring stakes before the flowers appear. Phlox are greedy plants, so apply a mulch 5-7cm (2-3 in) deep of well-rotted garden compost or manure in early spring. Shear off the spent flowers to prevent reseeding. If the leaves show signs of powdery mildew, cut down to the ground and dispose of the affected foliage, but do not compost it. Clear away the debris around the plant to reduce the chances of reinfection. Cut down to the ground in autumn. Lift and divide large clumps in autumn and spring.

Dahlia ‘Black Narcissus’ (dahlia tuber) £3.49
Position: full sun Soil: fertile, humus-rich soil Rate of growth: average Flowering period: July to September Flower colour: Other features: excellent cut-flowers Hardiness: half hardy (may need winter protection) Garden care: Dahlia tubers can be planted outside after frost, or started off in pots under glass in late winter to early spring. Plant them horizontally approximately 12cm deep, making sure the ‘eyes’ are uppermost. Allow enough room between each tuber so the plants can grow and spread to their full size without being over-crowded. While in growth, provide a high-nitrogen liquid feed each week in June, then a high-potash fertiliser each week from July to September. Stake with canes or brushwood if it becomes necessary. In mild areas, leave them in situ over winter, but protect the crown with a generous layer of dry mulch. In colder areas, carefully lift and clean the tubers once the first frosts have blackened the foliage and allow them to dry naturally indoors. Then place the dry tubers in a shallow tray, just covered with slightly moist potting compost, sand or vermiculite and store in a frost-free place until planting out again.