Spotlight on Dianthus
Joe Gadbois, April 25, 2024
One of my all-time favourite perennials, which I feel everyone should have in a sunny spot in the garden, is Dianthus (better known as pinks). This plant has nearly every trait that people are looking for in perennials: they’re fragrant and long blooming, attract pollinators, drought tolerant, undemanding, have attractive foliage in addition to the flowers, are well-behaved; and, provided you select the right varieties and plant in the right location, they are also reliable and winter hardy.
Breeding in recent years has really brought this lovely group of plants to the next level. In the past, winter hardy varieties for Alberta were mainly restricted to single flowered varieties which would lightly rebloom if deadheaded after the initial flush. New and recent introductions, however, have given us a wider range of flower forms and colours on plants that are continuously blooming and hardy to zone 3.
‘Mad Magenta’ is my current favourite. This compact variety has the biggest flowers of any Dianthus – over 2 inches wide – in an intense magenta-pink shade, and it continuously flowers all season. I planted 3 in a raised bed last year, and they bloomed nonstop from May until November! All 3 have survived the winter, and this variety is rated hardy to zone 3.
The Olivia series represent recent breeding which gives us single flowers in a number of vibrant colour combinations, atop low mounds of attractive blue-green foliage. These are also continuous blooming and are hardy to zone 3. The Constant Beauty series is another great option, with everblooming double flowers and hardy to zone 3.
The Sunflor series is similar to the Olivia series but with double flowers. These look like little carnations, the flowers held just above mounds of blue-green foliage. Again, they will bloom continuously all season and are hardy to zone 3!
The Rock series are, as the name suggests, ideal for rock gardens. These have more of a mat forming habit with beautiful single flowers. While the rebloom on these is not as strong as on other series, you will have flowers on them all season and they are hardy to zone 3 as well.
Of course, the tried-and-true older varieties are still well worth planting. I don’t think ‘Neon Star’ and ‘Fire Star’ will ever disappear because they are just so good. The former is smothered with neon-pink flowers in spring, the latter with deep red blooms. These don’t rebloom as strongly as newer varieties, but they are still among the best early season bloomers you can plant. The icy blue foliage looks great even without flowers. A couple other reliable older varieties worth trying are ‘Pink Fire’ and ‘Pikes Pink’.
Dianthus should be planted in a sunny location and must have well-drained soil. Dig out heavy clay soil and replace it with good garden mix available in our bulk yard at Greenland. Amend the soil with some compost or Sea Soil. Keep newly planted Dianthus evenly moist until established. Established plants are drought tolerant but will do best with a deep watering about once per week during extended periods of hot, dry weather. Because Dianthus are evergreen, do not cut them back in fall; instead, clean up any dead foliage in spring.
At the time of writing, our perennial department has a nice selection of Dianthus, but more will be arriving in the coming weeks, including all the varieties mentioned! If you are looking for something low growing with real flower power that doesn’t need a lot of water for a sunny location, Dianthus should be at the top of your list!