Dianthus are small 1-inch flowers in shades of pink with ruffled edges. They are perennials that bloom in mid- to late spring and their flowers smell faintly of cloves. Dianthus grow about 12-inches high and have finely spiked blue-green leaves. They grow well in containers, rock gardens or as edging plants for perennial flower beds.
Choose a spot for dianthus that gets at least 4 to 5 hours of sun per day. The area should have rich, moist soil that is well-drained.
Improve the soil. Dianthus like a slightly alkaline soil, so don’t use peat moss to improve it. Spread a 2-inch layer of compost and a 1-inch layer of well-rotted manure on the surface of the soil. Dig them in by turning the soil over with a shovel. Rake the area smooth.
Plant transplants 12 to 18 inches apart. Make sure you set the plants so that they are growing at the same level as they were in their nursery pots. The growing point of the plant should be even with the surface of the soil; do not plant them so the stems are buried.
To start dianthus from seed in the garden, sow seeds one-eighth inch deep. Firm soil over the seeds. Mist daily until germination occurs in 7 to 14 days. Thin the seedlings when they are 2 inches high so they stand 12 to 18 inches apart.
Water dianthus sparingly. Their foliage will turn yellow if they are over watered. These plants can get by on less than an inch of water per week.
Remove faded flowers to encourage more blooms. Dianthus will continue to bloom until past mid-summer if the spent flowers are regularly cut off. Leave a few faded flowers on the plant to produce seed, if desired.
Fertilize Dianthus every 6 to 8 weeks with an all purpose liquid fertilizer, applied following the manufacturer’s recommended quantities.
Dig up and divide Dianthus every 3 to 4 years, or when they begin to produce fewer flowers. Insert two garden forks back to back into the center of the plant and gently force it apart into two sections. Plant each section to form a new plant.