Dianthus and Carnations

How to choose dianthus plants

The Doris Dianthus is one of the classic garden pinks: salmon pink flowers with a deeper eye, a strong clove scent, and stems long enough to pick. Border Blue Dianthus is a hybrid garden pink for edging and the front of beds.

The Oscar carnations are compact plants with double flowers, suited to pots and the front of a sunny bed. The colours are in the names: the Oscar White Carnation, the Oscar Cherry and Velvet Carnation and the Oscar Pink and Purple Carnation. Grow pinks where you want a low, spreading mat that lasts for years, and carnations where you want a bigger flower close to the house.

Where dianthus works

Dianthus suit cool temperate, warm temperate and Mediterranean climates, and inland gardens with dry summers. They are frost hardy and take coastal conditions. What they dislike is a wet, humid summer, which rots the crown. In the subtropics grow them in pots or raised beds of gritty mix, keep them out of overhead summer rain where you can, and expect a shorter life. They are not plants for the tropical wet season.

They are natural companions for our rockery plants, they are well suited to the plants for pots, and the scented kinds earn a place among the fragrant plants near a path or doorway.

Dianthus can cause a mild stomach upset in pets that eat the leaves, so keep pots away from animals that chew plants.

Planting and spacing

Choose a position with at least six hours of sun and soil that drains fast. Dianthus prefer neutral to slightly alkaline soil, so add a little garden lime or dolomite where the soil is acid. In clay, raise the bed and work in coarse sand or fine gravel. Space plants 25 to 30 centimetres apart. Set the crown at soil level, never below it, and keep organic mulch away from the stems. A gravel mulch suits them better.

Care basics

Water at the base and let the soil dry a little between waterings. Feed lightly in early spring. Too much nitrogen gives soft leaves and few flowers. Remove spent flowers to keep new buds coming, and shear the plant over lightly after the main spring flush. Do not cut into bare woody stems, which are slow to reshoot. Pinks become woody and open in the centre after three or four years. Replace them then, or strike cuttings from non flowering shoots in late spring or autumn.

Common questions

What is the difference between pinks and carnations?

Both are dianthus. Garden pinks are low, mat forming and long lived with smaller scented flowers. Carnations are bred from Dianthus caryophyllus and have larger double flowers.

How long do dianthus flower?

The main flush is in spring, with repeat flowers through summer and autumn if you remove the spent blooms.

Why is my dianthus dying in the centre?

Usually age or wet. Old plants turn woody in the middle, and poor drainage or humid weather rots the crown. Improve drainage and replace old plants.

Do dianthus grow well in pots?

Yes. Use a free draining potting mix, a pot with good drainage holes and a position in full sun.