How to Keep Dianthus Blooming

There are approximately 300 species and 27,000 cultivars of the flowering plants known collectively as dianthus (‌Dianthus‌ spp.). Also referred to by the common name "pinks," because their frilly petals resemble fabric that has been cut with pinking shears, these plants are a staple bedding plant in cottage gardens and cut-flower bouquets.

Dianthus has fragrant flowers that come in almost every imaginable shade of pink, purple, magenta, red, yellow and white. There are also bicolor cultivars on the market.

Dianthus plants may be annuals, biennials or perennials depending on the cultivar. Perennial varieties are hardy in U.S. Department of Agriculture plant hardiness zones 3 to 9.

When Does Dianthus Bloom?

Native to Europe and Asia, dianthus plants bloom for several weeks in late spring and early summer. For example, China pinks (‌Dianthus chinensis‌, zones 6 to 9) typically bloom from April to June, while carnations (‌Dianthus caryophyllus,‌ zones 6 to 9) bloom in June or July. Cheddar pinks (‌Dianthus gratianopolitanus‌, zones 4 to 8) are in bloom in May and June.

Some dianthus cultivars will bloom from spring until the first frost in early fall. They include sweet William (‌Dianthus barbatus‌, zones 3 to 9), which is a short-lived perennial dianthus often grown as a biennial.

David J. Stang, CC-SA 4.0, via Wikimedia Commons

Growing Dianthus Plants

Dianthus plants flower best when they are grown in full sun, which means they receive at least six hours of direct sunlight every day. However, many varieties of dianthus do not handle heat and humidity well and appreciate afternoon shade on hot summer days.

While dianthus can handle different types of soil, they perform best in moist soil that has a neutral or slightly alkaline pH.

Well-drained soil as well as air circulation are key to avoid root rot, stem rot and other diseases that can kill dianthus plants. For this reason, it is best not to apply mulch around your dianthus.

Keeping Dianthus Blooming

In addition to providing proper soil and light conditions, you can keep your dianthus plants reblooming in late summer by fertilizing them and deadheading the dianthus flowers.

Fertilizer

One way to encourage your dianthus plants to rebloom is by feeding them every six to eight weeks during the growing season with all-purpose liquid formula. Light feeding is sufficient.

Deadheading

Deadheading, which simply means removing the spent flowers, can also extend dianthus bloom time. Dried-up flowers should be removed promptly if you want the plant to bloom again.

When they begin to fade in the summer and are pruned all the way down to their basal foliage, dianthus plants often produce flowers again within a few weeks. Pruning individual flowers can take a lot of time, but shears can be used to efficiently prune many dianthus plants at once.