Dianthus

Name: Carnation, Dianthus (Dianthus Plumerius).

Height: Up to 60cm; ground covers to 15cm.

Foliage: Grey-green stems and leaves similar to carnations.

Climate: Sub-tropical to cold temperate; tolerates cold nights; susceptible to fungal diseases in high humidity.

Soil: Not fussy, but does prefer good drainage; pH 7–7.5 (slightly alkaline) preferred.

Position: Full sun to light shade.

Flowering: Single to double blooms, from white to deep mauve and bright red; similar to carnations.

Feeding: Use a long-term controlled-release fertilizer as directed on the label.

Watering: Water regularly, especially during hot weather.

Appearance of Dianthus

Dianthus is very similar to carnations (Dianthus Caryophyllus), although it is somewhat smaller in both stature and flower size. Height ranges from around 15–60cm, depending on the variety. Some varieties are upright, while others are mat-forming.

Plants have grey-green stems and leaves. Their flowers may be single or double, and are usually carried on stems that hold them well above the foliage. When the stems are long enough, they make good cut flowers for indoor vases.

How to plant Dianthus

Plant seedlings out any time from spring to autumn in warm temperate areas, or spring to summer in cooler regions.

Space them about 30cm apart, and water in with a plant starter to help them establish quickly.

Choose an open, sunny position and a site that drains reasonably well after watering or heavy rain, because Dianthus can be susceptible to root rot in soils that stay wet for long periods. Dense shade will inhibit flowering.

Growing Dianthus in pots

Dianthus can also be grown successfully in window and planter boxes, hanging baskets and as a filler around a shrub or tree in a large tub. Use a premium-quality pot and tub potting mix that includes water-storing crystals to improve moisture retention over summer.

How and when to prune Dianthus

Dianthus will flower freely for several months once the weather warms in spring. The flowering period can be significantly extended by trimming off old flowers as they fade (dead-heading). This process redirects the plant’s energies and encourages more growth and more flowers.

Flowering can also be promoted by applying a water-soluble or liquid plant food every three or four weeks from mid-spring through to the end of summer.