Five-star plant selection
Percy Thrower looks at the best herbaceous perennials for the garden
FEW plants have undergone a greater change in conventional use in the past 25 years than herbaceous perennials. These plants, which were traditionally grown in herbaceous borders, are now rarely used in this way except in public parks. As gardens have become progressively smaller, it has become increasingly difficult to allocate sufficient space for borders devoted exclusively to herbaceous plants, which have had to take their place along with other types of plants in a partnership designed to create the greatest possible effect with the last expenditure of labour.
When these are the objectives, it becomes even more essential to make use of exclusively five-star varieties. Here are a few suggestions.
This is one of the most handsome foliage plants and the tall stiff spikes of curiously hooded maroon-purple and white flowers in late summer are most arresting. There are several species and varieties, but one is outstanding for the size and quality of both leaves and flower spikes. Its name is
A. mollis Latifolius Group, or for short just
A. latifolius, which is what it may be labelled in the nursery or garden centre.
These are the yarrows of which there are a great many kinds, but two are outstanding for the contribution they can make either planted alone or in association with other plants. One is deep-yellow ‘Coronation Gold’,
Achillea notable for its very extended flowering season from midsummer to autumn; the other is ‘Moonshine’, with grey-green ferny leaves and flat heads of flowers in an unusual shade of sulphur-yellow.
Here I am concerned with the fibrousrooted herbaceous anemones known collectively as Japanese anemones, and all flower in late summer and early autumn. They produce attractive flowers ranging in colour from white to deep rose and in height from 2-4ft (60-120cm). They all will thrive just as well (perhaps even better) in shade as in sun. I pick as specially good for small gardens the 2ft (60cm)-high reddish-pink
x ‘Profusion’, but
Anemone hybrida if you want a white colour, ‘Luise Uhink’ is the one to go for.
4 Aster [Symphyotrichum]
Asters have engaged the attention of plant breeders for more than 40 years and hundreds (maybe thousands) of varieties have been produced, many of them very good indeed. But some have deteriorated with age and some have been weakened by the attacks of pests and diseases.
As a result, relatively few varieties stand head and shoulders above the rest by virtue of their health, vigour and beauty. Prominent among these are A. novi-belgii ‘Marie Ballard’ [Symphyotrichum novi-belgii ‘Marie Ballard’], perhaps the finest blue Michaelmas daisy ever raised, with double flowers; ‘Fellowship’ with huge soft petunia-purple flowers; ‘Ernest Ballard’, carmine-rose; and Winston S. Churchill, with smaller flowers than the foregoing, but such a lot of them and of such a rich beetroot-red that it can hold its own in any company.
These are the bellflowers and there are a lot of good ones to choose from, some more suitable for rock gardens, walls or paving than for beds and borders. Campanula carpatica is a dual-purpose plant suitable either for a rock garden or for the front of a bed since it is clump forming and about 9in (23cm) high. The bell-shaped flowers look up at one and are showy. C. carpatica var. turbinata ‘Isobel’ has particularly good violet-blue flowers and C. carpatica f. alba ‘Weisse Clips’ is an outstanding white.
If there is room for a tall plant, 5ft (1.5m) high and spreading out in an elegant shuttlecock of growth, plant some form of C. lactiflora, which can be had in white and various shades of blue and lilac. My choices are ‘Prichard’s Variety’ for blue and ‘Loddon Anna’ for lilac.
These splendid aristocrats of the garden have been so highly bred that many varieties are quickly superseded by others of even greater excellence, or maybe the old ones decline in vigour and quality. But a few varieties seem to be timeless, declining little, if at all, with age and always appearing in nursery lists. For those who prefer to renew their delphiniums fairly frequently from seed, a good strain of Pacific Giants can prove most rewarding.
These look much like short Michaelmas daisies, but they start to flower much earlier, most in June, a few in July, and though summer is the period of their display, some will continue to produce a few flowers even in the autumn.
‘Foersters Liebling’ is the best deep rose-pink variety and there is a series of excellent hybrids raised by Alan Bloom with names such as ‘Sincerity’, ‘Dignity’ and ‘Felicity’, which are all good and offer a wide choice of the other typical erigeron shades of lavender, purple and pink.
These are among the gayest of daisy flowers, but they need to be grown in well-drained soil and sunny places, and to be lifted and divided at least every second spring if they are to prove really perennial. Typically scarlet with an outer ring of yellow, there are also all-yellow varieties and others in which the two colours have become blended to produce various shades of orange and bronzy-red. x
Gaillardia grandiflora ‘Mandarin’ is a splendid orange-flame example of this blending of colours. ‘Ipswich Beauty’ is a real startler if you prefer the colours kept separate.
It takes a long time to accustom new gardeners to the fact that the scarlet or pink-flowered plants they have always thought of as ‘geraniums’ are pelargoniums and that the true geraniums are hardy perennials, most of which have blue flowers. They are all very easily grown and most enjoy chalk or lime in the soil. This is certainly true of
x ‘Johnson’s Blue’, a
Geranium johnsonii lovely form of our own native meadow cranesbill, which will produce a profusion of violet-blue flowers from June to September.
Like erigerons and gaillardias, heleniums grow so quickly they can starve themselves out unless they are lifted and divided every second or third spring.
Fortunately, this is very easy to do since they can be split by hand and quickly re-establish themselves. Some kinds are rather too tall for any but big
gardens, but ‘Wyndley’ and ‘Moerheim Beauty’ are ideal, 2½-3ft (75-90cm) high, the first with yellow and mahogany-red flowers, the second a rich copperycrimson throughout. If I were confined to one helenium, ‘Moerheim Beauty’ is the variety I would choose.
■ In AG 26 June Percy Thrower concludes his five-star plant selection of herbaceous perennials