Rare colors, shapes brighten late-season garden palette
Rare colors, shapes brighten late-season palette
As the season begins to turn into late summer, our perennial gardens are mostly filled with shades of yellow and gold, as all the various yellow daisy-type flowers have peaked. Often at this time gardeners begin to think of the upcoming fall season and inevitably of fall garden mums. While I love chrysanthemums, especially the single flower types such as 'Clara Curtis', there are so many other wonderful perennials that can be used in the late summer garden to offer a change of pace from the bright yellows of August.
Blue is always a difficult color to find in the flower border but late summer brings about the bloom of the blue mist shrub, Caryopteris x clandonensis. While technically a small woody shrub, it is great for color in the late summer garden. When mature, it forms a compact mound about 3 feet to 4 feet high and 3 feet wide. It has spikes of fuzzy blue flowers that are a magnet for butterflies in late August and into September. Blue mist shrub is a tough plant, very tolerant of the heat, humidity and dryness that often characterizes this time of year. It loves full sun and well drained soils but its one drawback is that it is short lived, often lasting only about five years in the garden. However, during those years it can be a real "wow" factor in the border. As with other small woody stemmed plants that are used in the perennial garden, blue mist shrub should not be pruned back in the fall. Wait until the following spring when new growth appears and trim it back at that time. There are many cultivars of blue mist shrub; some offer deeper blue flowers, some have variegated foliage. One of my favorites is 'Sunshine Blue,' which has golden leaves and blue flowers — a beautiful combination! It has nice compact growth and really pops in the garden. 'Dark Knight' has the darkest blue flowers of all the many cultivars and 'Longwood Blue' has silvery leaves with sky blue flowers on a 2-inch-tall plant.
The genus Helenium has the unfortunate common name of sneezeweed, even though it is not responsible for causing allergies. It blooms at the same time as the inconspicuous ragweed and takes the blame, along with goldenrod, for itchy eyes and noses. This great perennial is native to the U.S. and is named after Helen of Troy! The large 2-inch to 3-inch flowers are characterized by a circle of wide petals, with three indentations at the end, surrounding a conspicuous central dome. Helenium comes in a range of autumnal colors such as orange, yellow, red, copper, and mahogany. It tends to grow quite tall, 4 feet to 5 feet, if not pinched back during the growing season. Plants should be cut back in early June to promote more compact growth and to encourage branching, which produces more flowers. Sneezeweed enjoys full sun and soils that are moisture retentive and is very adaptable to winter conditions. The cultivars 'Helena Red' and 'Helena Gold' are naturally more compact, topping off at 3 feet. 'Moerheim Beauty' is one of my favorites and has bronze-red flowers with a black central dome. Sneezeweed should be cut back by one-half when it has finished blooming.
Toad lily has a common name that doesn't exactly lend itself to thoughts of beauty but it is a most beautiful plant that blooms in September. Belonging to the genus Tricyrtis, toad lily is perhaps more unusual than flashy, and is possibly best viewed close up. This plant will form a compact clump of arching stems ranging from 6 inches to 3 feet, depending on the species. The orchid-like flowers are formed at the ends of the stems and are usually shades of purple with various colored spots, depending on species. The Formosa toad lily flower is a shade of lilac with scarlet spots, while the common toad lily has pale purple to white flowers. It will often be in bloom for up to six weeks. Toad lilies are a great plant for late color in the shade garden and are great companions for Hostas. There are many cultivars available; two that stand out in the garden are 'Autumn Glow', which has dark green leaves with a wide border of gold and amethyst flowers with dark purple spots, and 'Emperor', which has all gold foliage and 1-inch-wide dark purple speckled flowers.
Another plant with a less than enticing common name is hairy alumroot, which most people would recognize by the genus name of Heuchera. This is not the Heuchera with colorful foliage that most gardeners are familiar with. Instead it is the species H. villosa, which is native to the Southeastern US. This species has fairly large, rounded, heart-shaped leaves; both the leaves and the flower stalks are hairy, hence the common name. The cultivar "Autumn Bride" has deep green leaves and puts on a spectacular display of flowers from late August until frost. The flower spikes are covered with many small, creamy white flowers and they light up the partly shaded garden, especially when planted in groups.
There are many other perennials which offer great color in the late summer and early fall garden. Some that come to mind include turtle head (Chelone species), Japanese wax bells (Kirengeshoma palmate), and Japanese anemone (Anemone hupehensis), among others. If you are interested in having more color in your garden at this time of year, now is the time to visit your favorite garden center to purchase and plant these beauties. You will be rewarded next year when they come into bloom.
Hot, dry weather encourages red spider mites. If you aren't sure the pest is on your plant, place a sheet of white paper under the plant and shake. If you see little bugs crawling, you have spider mites! These pests can destroy a plant quickly. A good strong spray from the water hose every three to five days will discourage these pests. Or use horticultural oil or insecticidal soap as needed. Apply a water-soluble fertilizer to annuals for the last time this season. Keep them dead-headed and they will look great until frost.