September

Pennisetum alopecuroides is an especially appealing species, it changes its appearance and colour throughout the growing season. In late summer graceful fountain-like plumes emerge in profusion, they slowly change colour to a blend of green, soft pinks and light-colored maroons before maturing to light tan.

Pennisetum alopecuroides var. viridescens has broader leaves and darker flower heads than the regular species and, growing to around 60cm tall, it is also slightly smaller. It has graceful smoky purple-black plumes that contrast nicely with the slender arching, glossy, deep green foliage.

Awarded a Fleuroselect Medal for striking colour, plant habit, and flowering performance, Penstemon barbatus 'Twizzle Blue' is a first year flowering perennial that will add height and high-impact colour to the border, giving superb flowering performance from mid to late summer.

Penstemon barbatus 'Twizzle Coral' adds a graceful twist to the garden. A first year flowering perennial, that is hardy and vigorous, it boasts twice the length of flowering stems, giving longer, more elegant wands for the vase while preserving the natural elegance of Penstemon barbatus.

A winner of both an AAS and Fleuroselect Awards, Penstemon ‘Twizzle Purple' is a first year flowering perennial that boasts twice the length of flowering stem. Strong, trouble-free plants produce trumpet shaped magenta-violet blooms that flutter all along tall, slender stems.

Russian Sage is one of the great garden plants of all time, but if you've been frustrated by their floppy nature, this new variety will be a welcome addition. Growing to about 60 to 75cm tall, Perovskia atriplicifolia 'Taiga' is also the first Russian sage available as a first year flowering perennial.

Persicaria orientalis ‘Cerise Pearls’ is a new, modern-day variety that grows to a more manageable height of 100 to 140cm . Tall enough to give the same airy effect, yet so much easier to place in the garden. From August to October the whole plant is spectacularly draped with long, dangling, velour-like cerise tassels.

Tall garden phlox are a beauty to behold, the large, dense flower clusters, produced in abundance during summer. Phlox Hybrids Mix is a perennial, cultivated strain. The colours are wonderful, the sweetly fragrant, evening scent is captivating and they are very easy to grow.

The physostegia has prolific dazzling tubular flower spikes which are arranged on distinctly square stems. This oddly named perennial is perfect for the middle of a mixed or herbaceous border. The flowers are on swivels that can be bent right or left on the stem - a useful feature for floral displays.

The white form of the lovely Jacobs Ladder, named after the slender, fresh green leaflets arranged like the rungs of a ladder. Blooming in late spring to early summer, the bright foliage and white flowers will brighten shady locations. Both the flowers and the attractive ferny foliage are excellent for cutting.

Collected at altitude in Japan and introduced in 2006, Polemonium yezoense 'Purple Rain' is one of the best new introductions in recent years. With bronze-purple lacy foliage, dark stems and violet-blue flowers, it is the darkest flower form of Polemonium available.

Potentilla 'Helen Jane' is a beautiful new semi-dwarf cultivar that displays gorgeous crimson-eyed, bright pink flowers, with petals that are attractively crinkled just like crepe paper. Flowering over a long period, new buds open repeatedly in a long succession, from late June to September.

Venerating a former plant curator at the Royal Botanic Garden in Edinburgh, Scotland, 'Ron McBeath' is a beautiful new semi-dwarf cultivar. This diminutive potentilla repeat-flowers for months, sending up wands of rosy carmine flowers even in shade. It outlasts other potentillas by far.

This attractive plant will be equally at home in the flower border or keeping company with the sage and thyme in your herb garden. Delightfully aromatic, the floral-peppermint scent is subtly different from other mints. Mountain mint is a great nectar plant, its honey is much sought after.