Perennial dianthus is often called Sweet William, due to its spicy fragrance with hints of clove and cinnamon. Related to carnations, but much smaller and more delicate, dianthus plants make a cheerful addition to any garden.
Although some species can get up to 18” tall, most dianthus are usually only about 6” tall and about half as wide, so plant along the edges of borders and beds for best effect.
Flowers are most often pink, white, or variegated, some even with red hues, blooming from spring all the way through fall.
They can take full morning sun but will perform much better if given afternoon shade.
The most challenging aspect may be your soil, as dianthus prefer growing in loosely textured soil with plenty of organic matter.
These delicate looking plants are not as hard to maintain as their appearance might suggest, but you do need to be careful with watering. Dianthus need regular irrigation, but develop disease issues if they remain too wet. Water regularly, especially in the hottest, driest time of summer, but do so only in the morning and try to keep the leaves dry at all times.
And keep mulch a considerable distance from individual dianthus plants. If the area around dianthus stays overly wet for too long, not only will the soil be too wet for the plant, but the high humidity around it will be a problem. Keeping this delicate soil balance of adequate moisture but low relative humidity, is the most challenging aspect of successfully growing dianthus.
Full, bright morning sun, which will decrease air moisture around the plant, is critical.
For best growth and blooms, fertilize every six to eight weeks with a balanced fertilizer (equal or relatively equal amounts of nitrogen, phosphorus and potassium).
Remove spent blooms and lightly trim to encourage new growth.