Dianthus

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Dianthus is a large genus of plants that contains several common ornamental plants. Most are perennials, and most have similar grass-like foliage with dainty pink fringed flowers. A few are annuals. Some are mounded, some are spreading, some are single flowered, and many are double flowered. They come in a range of colors — mostly pink, white, red, and purple shades.

In fact, the English word “pink” originated with the name of these flowers, not the other way around. The common name for Dianthus is “pinks,” which were called that because of the jagged edge to the petals that looks reminiscent of a cut made by pinking shears.

Climate
This depends a little on the exact species of Dianthus that you have. A few are annuals, and will set seed before first frost. Other perennial types are hardy all the way down to USDA zone 3, while others are more sensitive and only hardy down to USDA zone 5. Many of them bloom primarily in spring and will go dormant during the hottest part of the year, but will come out and flower again in the fall. They do not do well in humidity, so those in particularly humid climates may have trouble keeping these flowers happy.

Sun
Dianthus like full sun, so make sure to plant them in an area that gets at least 6 hours of direct sunlight a day.

Soil
Dianthus prefer slightly alkaline soil. If you need to “sweeten” your soil, or make it more alkaline, mixing a little gypsum into your beds prior to planting can help. They also need well-draining soil. They do best if you mix a little gravel and mulch around the base to keep the leaves off the ground. Avoid organic heavy soil amendments and mulches that hold onto a lot of water.

Fertilizer
Above, we say to avoid really organic, heavy soil — while that is true, Dianthus do like feed. This is best accomplished by side-dressing in a balanced fertilizer, either regularly throughout the season, or only a couple times as a slow release. Compost is good for most things, but if your compost holds onto moisture too well, it’s not a good fit for a Dianthus planting.

Water
Water only the soil at the base of the plant, and avoid getting water on the leaves or the crown. Let them dry out between watering. Try not to apply too much water to the surrounding area where the humidity in the microclimate may get too high. 

Pests and Diseases
As mentioned above, it is very important to avoid getting the crown of a Dianthus too wet. They can be susceptible to crown rots and other funguses. Prevention is always the best when it comes to these diseases. Keep the water off the leaves, and make sure you’re watering early enough in the day so the water has had time to dry off prior to nightfall.

Spider mites and aphids are also attracted to Dianthus.

If you find yourself with pests or fungus that is getting out of control, you can use an insecticide or fungicide from a garden center. Always be sure to read the label and follow manufacture instructions. More is not always better!

Maintenance
Deadheading will encourage more blooms, avoid volunteer seeds, and keep the plant looking tidy. Dianthus usually grow in mounds, so they tend to look really good along borders even when not in bloom. In the spring, you can divide the clumps to make more plants.

Many varieties of dianthus have a lovely fragrance. Some varieties have a spicy scent like cloves or fall spices. Others are a little sweeter, and yet others are a little chocolatey. The fragrance is subtle, but it’s lovely. Dianthus flowers are also edible, and can be used as pretty garnishes for baked goods or salads. However, if you’re going to use your own Dianthus flowers for this purpose, make sure you know how they have been treated chemically. Some pesticides and fungicides, even those available for home use, are not approved for human consumption, and therefore should not be used on plants that you plan on ingesting. If your newly purchased dianthus is from a garden center with an unknown history, simply wait until you get a fresh crop of flowers before using any in food.  While you’re waiting for your first edible flowers, you can still use them as lovely cut flowers.