Gardening on the Rocks: An Introduction to Gravel Gardening

by Melinda Heigel, EMGV Intern

When you hear the term gravel gardening what do you envision? A scorching hot parking median filled with river rock and a few struggling trees? A sparse desert landscape devoid of anything lush and showcasing only the prickliest of plants? Well think again. Gravel gardening (also known as scree or dry gardening) offers so much more. You will now find gravel-type gardens starting to pop up at some of the world’s most beloved botanical gardens—including Chanticleer and our own NCSU’s J.C. Raulston Arboretum and Duke’s Sarah P. Duke Gardens. Juniper Level Botanic Garden in Raleigh has also adopted and amended this method with its very own crevice garden, substituting gravel with 100 percent PermaTill®, a pea gravel-like product made of slate found in North Carolina. Gardening with gravel and other hardscape materials offers a sustainable, lower-maintenance option that doesn’t sacrifice beauty. Legendary English gardener Beth Chatto, a pioneer of this style of gardening, described this type of method succinctly when she said, “This garden was not to be irrigated in times of drought. Once established, the plants must fend for themselves or die.”

Examples of gravel/hardscape gardening with the following plants (top left to right, top to bottom): Allium jesdianum (Ornamental Onion); Salvia nemorosa (Meadow Sage) and Silene virginica (Fire Pink); Delosperma dyeri (Ice Plant), Allium ‘Ostara’, and Agave x victosa. Photos by M. Heigel.

So if gravel gardening is good for the environment and good the gardener, what is it exactly? Typically, gravel gardening involves putting in some upfront work. It means creating a garden bed 4-5 inches deep with gravel laid directly on top of soil. The gravel should be uniform in size and can vary from pea gravel to ¼ inch and must be igneous or metamorphic rock, so it won’t break down over time. Typically, gardeners use their existing soil without amendments (J.C. Raulston has turned PermaTill® into their scree garden), and good drainage is a must.  Equally important in the design is an even thickness of gravel throughout—especially out toward the edges. More shallow areas of gravel only invite weeds. To achieve this, a good gravel garden should have a border 4-5 inches in height.  Bricks, metal edging, or even rocks are all options; you could even make the gravel garden a raised bed.  Gravel acts like mulch here: it suppresses weeds and means very low maintenance in the future. When preparing a site with gravel for this method of gardening all existing plant material should be cleared prior to planting.

Gravel gardens are intended to be in sunny, hot, and dry locations. Drought tolerant plants are the right choice for these hardy gardens.  While gardeners should plan to do a good deal of watering the first year while the plants’ roots are getting well established, this diligence will pay off.  This method’s water-wise and low-maintenance features really come into play in subsequent years as plants should require no supplemental irrigation thereafter. If properly prepped at installation and their spent plant material cut back well each spring, these gardens are devoid of many weeds and easy to maintain once they grow in.

In terms of garden design, many gardens grasses like our native Muhlenbergia capillaris (pink Mully Grass), Schizachyrium scoparium (Little Bluestem), and Nasella tenuissima (Mexican Feather Grass) make excellent backdrops for gravel gardens and offer great fall color and wintertime architectural interest. And while cool Cacti, Yucca, Agave and types of Euphorbia work quite well, options abound, including many natives. Some good choices for gravel gardens in our area also include the following:

  • Achillea milefolium (Yarrow)
  • Allium (Ornamental Onion)
  • Asclepias tuberosa (Butterfly Weed)
  • Aster
  • Clinopodium carolinianum (Georgia Calamint)
  • Coreopsis (Tickseed)
  • Echinacea purpurea (Purple Coneflower)
  • Lavendula angustifolia (Common Lavender)
  • Nepeta sp (Catmint)
  • Penstemon (Beard Tongue)
  • Salvia rosmarinus (Rosemary)
  • Salvia yangii (Russian Sage)
  • Sedum sp.
  • Stachys byzantina (Labs Ear)
  • Verbena canadensis (Rose Verbena)

At once earth friendly and gardener friendly, this low maintenance method could be a great addition to your garden repertoire.

Further Reading and Additional Photos of Mature Gravel Gardens

Gravel Garden Ideas from Chanticleer

Beth Chatto’s Gravel Garden

Gravel Gardening: The Planting Formula to Success (Scott Arboretum)

Horticulturist Lisa Roper discusses the Gravel Garden at Chanticleer Garden in Wayne, PA.
Video produced by Jonathan Monkemeyer & Bryan Christ.