Darling Dianthus

Sunday, September 15, 2002

Hard to classify in botanists’ parlance as strictly annuals or perennials, the Dianthus family offers fragrant spring flowers on neat plants with green or blue gray leaves. The ‘Pinks,’ as they’re called, are best grown as annuals where summers are cool and winters hard, except for those few perennial alpine varieties. From zones 3 and south to zone 9, popular varieties can be grown as annuals or short lived perennials.

To grow the annuals, plant seeds or small plants early in spring, or in fall where winters are mild. The popular ‘Telstar’ series Dianthus and seed packs of ‘annual pinks’ as well as traditional carnations are grown this way. The mounding Dianthus, usually shortlived perennials, grow larger in cool weather, survive truly cold and hot spells, and bloom as spring warms the air. All Dianthus prefer a very-well drained soil that is slightly alkaline. If your soil is acid, or if you amend with abundant amounts of organic matter in any soil, use lime before planting dianthus.

Perhaps the best known of this family is saucy Sweet William. The plants are10 to18 inches tall, with green leaves, 3-6 inches long on a dense green crown. The flowers hold themselves high on tufted heads, dozens of blooms in shades of white, pink, red, and purple. The flowers are fringed, many with colored eyes and contrasting rings of color. In a mixed arrangement, sweet william makes a bold contrast to single flowers like daisies and snapdragons, and imparts a distinct clove aroma.

Beloved by gardeners since the seventeenth century, the dainty flowers known as Pinks (Dianthus chinensis, D. x Allwoodii, etc.) grow either from low-growing mounds or dense clusters of upright leaves. Generally speaking, those with blue gray leaves are longer lived in the garden, and called perennial.

Bath’s Pink’ and ‘Camilla’ represent about thirty varieties that look like big pincushions in the garden, about one foot across and three inches tall. The flowers stand up straight above, on nearly leafless five inch stems. Every imaginable combination of single and double, fringed, ringed, and center-spotted (or not) can be found in solids and bicolors.

Taller leaves with at least an equal number of flower colors and types scattered throughout the stand mark the Allgood hybrid Dianthus, known for their profuse flowers. Singles and mixed colors on plants to one and a half feet tall bring fine texture, upright lines, and two inch flowers that can go on for two months, if deadheaded regularly.

By nature, many of these profuse bloomers are short lived, and indeed, some are grown from seed each spring or fall, as true annuals. Dianthus will also stop blooming if the plants get woody, if the centers die out from summer’s heat, or if the crown rots in cold, wet weather. So, to keep Dianthus in your garden for years, plan to multiply them as they grow.

Some will self seed in the garden with a little encouragement from you: as the plants set seed, remove mulch below to create a seedbed. Mounding types send out side shoots that you can easily root in a combination of sand and compost. Take cuttings of taller types; they’ll root in about two weeks in late summer. Transplant them right away to prevent stunting.

The biggest pest of Dianthus must be rust, a fungus disease that also attacks zinnias. Treat at the first sign of leaf spots (yellow on top, orange underneath the leaves) with a dust containing sulfur and repeat weekly during rainy weather. Good air circulation and excellent soil drainage will help prevent rust and the heat damage often done in midsummer to the crown’s center. 

Popular for centuries and grown by Thomas Jefferson at Monticello, the introduction of new varieties in both green and gray leaves means more dianthus to enjoy. At least three hundred varieties have been named, with more introduced (or re-discovered in the case of the heirlooms) each year. Take advantage of their spicy good nature: use them for edging beds and borders, fragrant ground covers, blue gray color, and cut flowers over a long season in  pots or garden beds.

Heirloom Pinks

Add a bit of history to your garden with centuries’ old Dianthus. Most are easy to grow, but be sure to take cuttings or lift a sideshoot or two every three years to keep them going in your garden...and your grandchildren’s!
‘Dad’s Favorite’--17th century--double white, laced with red and a maroon center
‘Pheasant’s Eye’--1690--semidouble white, with a red center
‘Rose du mai’--1800’s--fragrant, double lilac pink, ten inches tall

This is the unedited version of an article that appeared in Garden Almanac, a publication of GroGroup.

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