Turning up the Heat
Late summer perennials offer a great range of hot and vibrant colours for your borders. Ian Moss, from Ian and Teresa Moss, offers a selection of the best. - 11 September 2015
As the gardens and borders at Llanover House will demonstrate, late summer and autumn offer a great opportunity to develop and plant high impact borders in bright and fiery colour schemes. Why is this? Firstly, a great range of perennials in vibrant colours (reds, yellows and oranges) come into flower. Also, there is a good selection of these that are tall and which add structure and drama to your borders. And finally, these hot colours look especially effective in the lighting at this time of year, and combine well with the flowers and foliage of other late season favourites such as ornamental grasses and also with the autumn colours of trees and shrubs.
Here are just a small selection of our favourites:
Daisies are one of the archetypical flowers of late summer and autumn. There are a huge range available, including Helianthus, Rudbeckia, Helenium, Echinacea, Coreopsis and many others. For real impact, the taller daisies such as Rudbeckia ‘Herbstonne’ or Helianthus ‘Lemon Queen’ are fabulous back of the border perennials, reaching heights of 1.5-1.8m. We grew both in a windswept garden in Devon (the hot border in our current garden is still work in progress!) and neither needed staking.
For shorter daisies, there are a range of hardy rudbeckias, including the wonderful Rudbeckia subtomentosa ‘Henry Eilers’, with marvellous spoon shaped petals, and the well-known R. ‘Goldsturm’, used so effectively in the borders at Llanover.
Rubeckia subtomentosa 'Henry Eilers'
Heleniums are also wonderful daisies for hot borders. They range in height from 60-120cm, and in colour from bright yellow through orange to dark red, including many bicolour flowers. Our favourites, both for their colour and their vigour, are Helenium ‘Mardi Gras’, a Blooms of Bressingham introduction with lovely red and yellow bicolour flowers, and H. ‘Chelsey’, similar but with more red in the mix.
A few years ago it would not have been possible to include echinaceas in a hot border, but in recent years a whole host of new hybrids have been introduced in all shades of red, orange and yellow. Many also have a good scent. There are lots to choose from, but varieties such as E. ‘Tomato Soup’ (it really does do what it says on the tin!) or new variety E. ‘Orange Passion’ are in our view hard to beat. We are always being asked about the hardiness of echinaceas – the key to success in well-drained soil. Echinaceas can cope with very low temperatures (they are, after all, North American in origin) but dislike winter wet.
Echinacea 'Orange Passion'
Plants with upright, spire-shaped flowers add structure and focal points to borders (at any time of year) and there are good choices for late summer. Kniphofias are one example, with flowers in a range of hot colours from red to pale yellow. We currently grow examples from the dreadfully named but well selected ‘Popsicle’ range, with our favourite being K. ‘Mango Popsicle’, which is, well, mango coloured! Many
older varieties, such a K. ‘Nancy’s Red’ and K. ‘Tetbury Torch’ are all also great choices.
Kniphofia 'Mango Popsicle'
Also wonderful for late summer are perennial lobelias. A real stunner at 180cm is Lobelia tupa. Hailing from South America, this will not be reliably hardy for everyone but is worth a shot in the south, and will reward you with stunningly exotic scarlet flowers. Selections of Lobelia x speciosa are also very worthwhile; as well as hot flower colours, some also have dark red/purple foliage, for example L. ‘Russian Princess’. Dark purple flowers also mix well with the hot oranges and yellows, which allows us to include our favourite, Lobelia ‘Hadspen Purple’, which is a truly beautiful example.
Those of you who know us well are aware that I have a soft spot for salvias. Colin Roberts, from Adwell House, covered these in some detail in his article in our last newsletter, but we can’t resist including the wonderful, but tender, Salvia confertiflora, in our choices. You’ll need to take cuttings (which root easily) to overwinter under glass, but it’s worth it for the fabulous spires of red flowers throughout the summer.
Our final selection are crocosmias, bright and cheerful perennials from South Africa. Contrary to popular belief, most are not invasive but form sensible size clumps at a sensible rate! There are a huge range of varieties available, so which should you choose? In our view, the three used in the hot garden at RHS Rosemoor are difficult to beat. These include the dark orange-red C. ‘Emberglow’, another Blooms introduction, the more recent and stunning C. ‘Limpopo’, in peachy orange, and the yellow C. 'Columbus’. All are good doers and flower for a long period in the garden. We also covet, but have not yet grown, the aptly named C. ‘Hellfire’, the deepest red crocosmia we have yet seen.
There are many other choices for your hot borders that we have not even touched upon, such as the umbels of achilleas and sedums (especially those with dark red or purple foliage), the buttons of late season sanguisorbas and the attractive bottle brush flowers of persicarias. Combining these colours, heights and flower shapes together can produce truly stunning late season borders, as this photo of the hot garden at Rosemoor demonstrates so beautifully.
Ian and Teresa’s nursery in Somerset specialises in hardy and unusual perennials. They exhibit their plants at over 30 shows throughout the year. Plant enthusiasts can also buy their plants throughout the growing season at the Kilver Court nursery.