ROCKING THE ROCK GARDEN: DIANTHUS CHINENSIS V. ARMERIA MARITIMA

By Cassy Aoyagi:  While rock provides its own strong beauty to a landscape, few things are as inspiring as the delicate beauty of flowers willing to blossom between a rock and a hardscape. Dianthus chinensis and Ameria maritima present two options for rocking your rock garden.

Armeria maritima

Native to the northern hemisphere and found throughout California, Armeria maritima is commonly seen on coastal bluffs from central to northern California.  Its bloom period starts in early spring and extends into fall.  Like Dianthus, the flowers are long lasting when cut for display.

To keep Armeria maritima happy:

• “Mow” for More Flowers.  Deadheading Armeria maritima has elemental simplicity – mowing the flowers down, rather than cutting them one by one, will produce an immediate rebloom while saving time
• Provide minimal supplemental water. Armeria is a gem along the coast. In full sun, inland climates, it may have water demands that outweigh its benefits.
• Relax! While Armeria maritima stays small, it spreads quickly and covers a lot of ground in a small amount of time.
• Enjoy its beauty. The green basil growth of Armeria maritima, when not erupting with pink or white flowers, has the appearance of an actual, traditional lawn.

Armeria partners well with other coastal scrub plants like Lessingia, Aster firkartii, Yarrow, and ground cover sages to make a beautiful rock garden.

For more guidance on where to plant big dry ones, see our past Wet-to-Dry Exchange articles.

Dianthus Chinensis

Native to Europe and Asia, Dianthus produces a variety of vibrant colors. Using a smattering of the more than 300 varieties of Dianthus will produce all the color any rock garden could need. While green and blue foliage of the Dianthus cut flowers can easily be found at the supermarket, getting Dianthus to thrive in a Los Angeles garden is significantly less convenient.

Dianthus’ excessive demands include:

• A delicate balance between full sun, lots of water, and well-drained soil.  Although this is a thirsty plant, over watering Dianthus in poorly drained soils will quickly lead to fungus and death.
• Changing out every three months to sustain blooms.  While technically Dianthus can be treated as a perennial in LA, the need for constant deadheading can be more than one can manage to make it a year round component of your yard.
• Greenhouses.   Greenhouse or agriculturally grown plants like Dianthus place a heavy burden on our natural resources. Using precious water and costly energy to grow decorative flowers instead of local food and could be perceived as a less strategic allocation of our resources.
• Lots of friends and money.  Because Dianthus does not grow large, many are needed to cover a small space.  To make a splash, the upfront costs of installing Dianthus, let alone the costs of frequent replacement, can feel like a bit of a burden.
• A lot of work! To get the most out of your planting, regularly scheduled dead heading is required to keep the plants looking fresh and extend bloom periods.  If neglected, spent blooms create a scene, quickly turning brown all at once, covering the bright green foliage and making your annual bed an unsightly tangle of dried-out foliage. Regular replacement of Dianthus can keep a rock garden rockin’, but it results in higher maintenance costs, more labor, more water, re-establishment periods, and an increased need for fertilizer to extend bloom periods.  That’s a commitment!