The 2006 perennial plant of the year

Each year the association for perennial professionals, the Perennial Plant Association, chooses a plant of the year. This is a plant widely available, which performs well in many locations and conditions, is low maintenance, and is deserving of wider use. This year’s winner is ‘Firewitch’ dianthus, also seen by its original German name of ‘Feuerhexe’ or common name of cheddar pinks (Dianthus gratianopolitanus).

This evergreen perennial forms mats about four inches high, and up to 12 inches wide. Flowers rise above the silvery-blue leaves, reaching about eight inches high. They have been described as purplish-pink, hot pink, purple-red, or magenta. Whatever the name, they contrast well with the leaves and attract early-season butterflies. The fragrance is spicy like cloves, similar to many of its relative pinks.

Flowers bloom in mid to late spring. They may begin in March in Georgia and May in Vermont, and continue for several weeks. One of the attractions of ‘Firewitch’ is its longer bloom than many similar cultivars (cultivated varieties). In longer seasons they may even rebloom in late summer into fall.

This plant grows best in full sun and well-drained soils. It will tolerate part shade, but perhaps not bloom as well. A rock garden or raised bed is ideal. If soils are acidic, lime might be added to raise the pH. If too hot and dry, leaves will not be as lush and fewer flowers may be produced. Although plants will tolerate short dry periods, plan on watering if a long period of drought.

This dianthus is quite hardy, growing in USDA zones 3 through 8. In the coldest climates, add a light layer of mulch, such as from evergreen boughs, to protect the leaves. Remove any mulch as soon as any snow melts in spring to prevent crown rot disease. It is bothered by few pests, and is deer resistant.

As with other perennial plants of the year, this one is low maintenance. If they need pruning to keep to a certain size, leaves may be trimmed in very early spring, or after the first bloom. They also may be divided in early spring if needed, just as new growth is beginning. Division every three to five years may help keep plants vigorous, as they tend to be short-lived otherwise. Plants may also be propagated by rooting terminal cuttings (those from the ends of shoots).

In addition to rock gardens and raised beds already mentioned, this dianthus can be used in fronts of borders, sunny borders, and cottage gardens. Good companion plants include Siberian iris, low spring-flowering spurges, Carpatian bellflower, coral bells, perennial geraniums, lamb’s ear, threadleaf coreopsis, pincushion flower, blue fescue or blue oat grass, or golden yucca.

This perennial is a member of the pinks family, or Caryophyllaceae. The genus name “dianthus” comes from the Greek words dios and anthos, meaning divine flower or flower of the god Zeus. The species of this cultivar is native to western and central Europe. One of the locations where it grows wild is Cheddar Gorge in southwest England, the same as the origin of the famous cheese, from where it gets the common name Cheddar Pinks.

The word “pinks” does not refer to the pink color, but has two possible origins. One refers to the fact the petal edges are highly cut, as with pinking shears. The other possible origin is from the Dutch word “Pinkster” or the German word “Pfingsten” for Pentecost, which refers to the time it blooms.

‘Firewitch’ was introduced by a German nursery in 1957. Grown in Europe, it was unknown in this country until brought here in 1987. Pierre Bennerup, of the Connecticut wholesale nursery Sunny Border Nurseries, found it at a Dutch garden center, bringing back a couple plants to propagate and share with other growers. All the plants for sale in North America today, and that you perhaps have in your own garden, came from these original two plants.

Dr. Leonard Perry is Extension Professor, Department of Plant and Soil Science at the University of Vermont. Visit his website at http://www.uvm.edu/~pass/perry/index.html.