Plan for late color from perennials

Flower & Garden Magazine, June-July, 1985 by George Taloumis

Any seasoned gardener knows that perennials give their greatest performance in spring and early summer. Here in New England it comes in May, June, and early July. It is then that iris, delphiniums, Canterbury bells, Oriental poppies, pinks, peonies, lupines, painted daises, astilbes, gas plants, and columbines are at their most spectacular.

Thereafter comes a decline in perennial exuberance, much like the quiet that follows forsythias, azaleas, rhododendrons, and lilacs among flowering shbrubs and everygreens.

In the world of perennials, that decline has become known as the "August lull," a time when determined gardeners do their utmost to continue the color parade. Often the solution is to rely on marigolds, zinnias, petunias, and other annuals.

With planning, this late season lull can be overcome with the right perennials, but that even when lifting and dividing are needed, at least they are there to carry on.

Where to start? I find phlox a good choice, since many flower in both July and August, such as the white 'Rembrandt' and the pink 'Sir John Falstaff,' which with me covers a span of two months. If old headds are cut off to prevent seed formation, small latent flower clusters develop to give touches of color.

Globe thistle or echinops is a stalwart candidate, with spiny leaves and globular heads of blue-purple flowers, which are always alive with bees. The heads can be gathered in their prime and dried for winter bouquets. Spring is the best time to lift and divide large clumps.

Appearing late in the season are the hooded lavender or purple flowers of monkshood or aconitum. As a perennial, in our region it is as dependable as peony -- long lived, tough, and practically indestructible. Like peony, it resents distrubance. "Spark's Variety,' five to six feet high, is deep blue. Aconitum bicolor is white edged with light blue.

What would a late season garden be without rose mallows or hibiscus? Not much. These huge perennials (mine reached seven feet last summer) unfold gorgeous hollyhock-like blossoms of red, pink, or white. Many varieties and cultivars are available, 'Florabelle,' 'Southern Belle,' and 'Mallow Marvels' among them Japanese beetles relish the delectable blossoms, so be prepared to battle them. Large clumps will need an axe -- and a strong hand -- to sever them when dividing in the spring.

Kansas gayfeather or liatris is another standby. Its spikes of feathery lavender flowers have the distinction of starting to ope at the top and then proceeding to the bottom. This is Liatris pycnostachya, but last year for the first time I ventured into growing Liatris scariosa 'White Spires,' different, with its globular heads of delicate flowers along the spike.

Little grown is the intriguing sea holly or eryngium, a member of the carrot family that does well in poor, sandy soils in seaside gardens. It needs full sun for it to display its rounded heads of lavender blossoms remindful of globe thistles, except much smaller. Like them, it dries well.

Another to include is Stoke's aster, STokesia laevis, a low perennial under a foot high, growing best in sun and sharp drainage. Daisy-like heads are blue. 'Blue Star' and 'Blue Moon' are both light in tone. Stokesia is an excellent cut flower for its rare touch of blue.

Purple loosestrife, or lythrum, tends to come in July, but if deadheaded it develops side shoots to help brighten the late garden. Its spiked flowers add vertical accent. Although in the wild it is found in wet or boggy places, it is adapted to gardens with average moisture. A mulch helps it. Varieties like 'Morden Pink' and 'Morden Purple' are hardly weedy, but also consider the red 'The Beacon' and the fuchsia-pink 'Robert,' a dwarf under two feet.

Few know the mist flower, Eupatorium coelestinum, with soft lavender flowers on foot tall plants from August to frost. It is rarely grown toady. Use it for edging in sun or semi-shade, spacing plants a foot apart.

Somewhat better known is leadwort, Ceratostigma plumbaginoides, often grown as a ground cover, a use to which it is well suited. It grows eight to 12 inches tall; has dark green leaves that turn bronzy-red in fall, and deep blue flowers from August to September. As it is slow to make its appearance in spring, do not give it up as dead.

Also slow to show up is balloon flower or platycodon. The common name derives from the swollen balloon-like buds, which expand into striking star-shaped flowers. Although flowering starts in July, it goes on into September if old blooms are cut off. Mark its place with a bamboo or other stake so as not to disturb it unintentionally in spring. Platycodon grandiflorum attains two feet; P. mariesii is compact and lower. Both are violet-blue.

For dry, gravelly soils try the native butterfly weed, Asclepias tuberosa, whose flat heads of orange flowers are borne on two- to three-foot stems. The blooms are attractive to butterflies. This plant is tough, dependable, and non-aggressive.

Another native is bee-balm or monarda, growing to two or more feet tall, and topped with brigh red flower clusters that appeal to hummingbirds. It will grow in shade. This is a spreader. To control it, I grow it in bottomless containers of plastic, ceramic, or wood, as I do with mint. 'Adam' is clear red; 'Purple' is purple-red. 'Granite Pink' is a pink that enlivens the reds, as does the creamy white 'Snow White.'