HARDY, COLOURFUL PERENNIALS GIVE GARDENS LATE SUMMER SIZZLE
BRIAN MINTER
During the hottest part of summer, when many annuals require a lot more care and often look tired, some lesser-known, drought- and heat-tolerant perennials can refresh and bring our gardens to life. Many of them also carry their colour well into late summer and even fall.
Most experienced gardeners have discovered the beauty and resilience of rudbeckias, especially the five-star R. ‘Goldsturm,’ its closest competitor R. ‘American Gold Rush’ and the marvellous compact form of R. ‘Little Goldstar.’
Few, however, know of their giant cousin, R. laciniata ‘Herbstsonne,’ which begins to bloom just about now. Growing up to eight feet, its strong stems hold up well in autumn winds, and its large golden blooms, with their brown centres, keep performing into fall. It’s as old as the hills, but R. laciniata ‘Goldquelle’ is another late summer giant. Its fully double, golden yellow blooms love hot, dry weather.
Joe-pye weed or Eupatorium dubium (zone 5), with its pollinator-attracting, lavender-pink flowers, has been a much-celebrated late summer stalwart. Often reaching six feet in height, its open blossoms are seldom seen without butterflies. Eupatorium ‘Little Joe’ grows only four feet tall, and the new E. ‘Ruby,’ the most compact of all eupatoriums at 24 inches, is well suited to smaller spaces.
Anything blue adds a nice cooling touch during hot summer weather, and Russian sage is fast becoming a new garden favourite. Perovskia atriplicifolia (zone 4) has spike-like, lacy blue flowers and sports attractive silver-grey foliage, making it ideal to combine with the warm tones of echinaceas, rudbeckias and coreopsis.
Today, there are many more compact varieties, including P. ‘Little Lace’ (24 inches), P. ‘Blue
Jean Baby’ (34 inches), and P. ‘Crazyblue’ (18 inches), making them far more versatile in smaller gardens. They are quite heat and drought tolerant and bloom well into September.
Veronicas, often known as speedwell (zone 5), have suddenly become another top choice for late summer colour. The new series called ‘Moody Blues’ comes in a range of colours, including deep purple, blue, pink and white. With a little dead-heading, they will bloom from May well into October. They are also very popular as cut flowers, mixing beautifully with sunflowers, snapdragons and dahlias to create rich summer-garden bouquets. An older variety, V. ‘Charlotte’ has variegated white and green foliage and lovely white flowers. It is one of the longest, most continuous flowering varieties.
The lesser-known stokesia, or Stokes’ aster, is another heat- and drought-tolerant, late-blooming garden treasure. It grows about two feet tall, and from July into September it produces myriad fluffy, aster-like flowers that are also great used as cut flowers in bouquets.
It’s wonderful to have some perfume in our late-summer gardens.
If you have a shady spot, the old-fashioned cimicifuga or bugbane (zone 3) will fill it nicely with fragrance that lingers. They are just beginning to flower now. There are green foliage varieties, such as C. racemosa and C. racemosa var. cordifolia, but the real showstoppers are the richly black foliaged varieties because they contrast so magnificently with their spiky, pure white flowers.
Cimicifuga ‘Brunette’ and ‘Black Negligee’ are the most well known, and ‘Hillside Black Beauty’ has the darkest foliage of them all. ‘Pink Spike’ and ‘Chocoholic’ cimicifuga have pinktoned flowers and are also highly perfumed. They all grow from four to five feet tall and bloom into October.
When it comes to perfume, few other plants match the stunning fragrance of Oriental lilies (zone 4). In our gardens, we strategically placed them along many pathways so folks could fully appreciate their strong, lingering perfume. It is surprising that one bulb will become a significant clump, reaching over four feet in height, in just a few years and with an ever-improving scent.
Oriental lilies are available in a wide range of colours and bicolours. ‘Casa Blanca,’ a huge pure white, and ‘Stargazer,’ a beautiful deep pink with white outlines, are two of the most well known. Double oriental lilies are truly unique, and they also push out that lovely fragrance. They are certainly the No. 1 cut flower for summer beauty.
Few other perennials can equal the vigour and the bloom period of Japanese anemones (zone 4). They prefer morning sun and afternoon shade, and when given this ideal situation, they bloom profusely from early August well into October. Coming in shades of pink and white, they add a real touch of elegance in the garden. I think the pure white, single flowers of A. ‘Honorine Jobert’ are the classiest. More compact varieties, such as the A. ‘Pretty Lady’ series, are available in both single and double flower forms. I think the singles are the best. Japanese anemones are so vigorous that landscape architects are using them as ground covers.
As summer pushes into fall, these reliable varieties will carry your garden forward beautifully. Now is a great time to add them to your garden mix.