An Ode to Clay
“Ugh, this clay soil.” My neighbor’s lament echoed what nearly every Piedmont gardener has said at one point or another. As we wandered through my relatively new landscape—blanketed in a thick layer of woodchips spread over the clay subsoil left behind by the builders—she was ready to commiserate.
I, too, used to gnash my teeth and wring my hands in frustration over the “clay soil” I thought needed fixing or fighting. But after a decade dedicated to native plant gardening, I now see it differently. Instead of lamenting, I practically sang my love song to clay—how incredible it is as a subsoil, how our native plants thrive in it, and how it quietly plays an essential role in creating soil for future generations of plants.
To this day, her amazement and proclamation—“I’ve never heard anyone talk so lovingly about clay!”—brings a smile to my face.
Clay is misunderstood. It’s not just a sticky, dense annoyance; it’s the foundation of life for countless plants. So let’s take a moment to celebrate this unsung hero of the Piedmont.
The Marvel of Clay: Why It’s Better Than You Think
Clay’s Size = Big Impact
Clay soil is made up of particles so tiny they’re practically microscopic. To put it in perspective:
- A grain of table salt is 100 microns across.
- A strand of hair is about 70-100 microns thick.
- Clay particles? They’re smaller than 2 microns—50 times smaller than a grain of salt and thinner than a single strand of hair.
This small size gives clay an incredible superpower: it holds onto nutrients like calcium, magnesium, and potassium better than almost any other soil type. It’s basically a pantry of goodness for plants, slowly releasing these nutrients as they’re needed.
Clay’s Moisture Magic
Clay also retains water like a champ. Sure, it can turn to mud when drenched, but that moisture is a lifesaver for plants during dry spells. In hot Piedmont summers, clay’s water-holding ability is like having a built-in irrigation system.
Plants and Soil: A Reciprocal Love Story
Clay may be the starting point, but plants take it to the next level. Here’s how the magic happens:
- Plants Stabilize and Improve the Soil
When native plants colonize exposed clay, they act like nature’s first responders. Their roots stabilize the ground, preventing erosion, while their fallen leaves and organic matter enrich the surface. Many so-called “weeds” also play vital soil-building roles, such as fixing atmospheric nitrogen or breaking up compacted soil with deep taproots, preparing the way for other plants to thrive. Over time, these pioneers break down the dense clay and begin forming a crumbly, nutrient-rich topsoil layer. - Clay Protects the Plants
Clay provides the nutrients and moisture plants need to thrive, even in tough conditions. Its density also makes it excellent at protecting roots during extreme weather. It’s a partnership: plants give clay life, and clay keeps plants thriving. - The Soil-Making Symphony
Here’s the real magic: plants don’t just need soil; they’re an integral part of making it. Through photosynthesis, plants pull carbon dioxide from the air and pump it into their roots as sugars. These sugars feed the microbes in the soil, sparking a whole ecosystem of life that works to break down organic material and mineral particles. Over time, this dance of plants, microbes, and minerals creates the rich, dark topsoil gardeners adore.
So next time you dig into that stubborn clay, remember: it’s not just (sub)soil—it’s the beginning of something beautiful.
Native Plants That Love Clay
You don’t have to fight your clay soil—work with it! Here are some Piedmont natives that thrive in clay subsoil and will often pop up on their own (if you put down the weedeater!):
🌱 Trees
- Eastern Redbud (Cercis canadensis)
- Sweetgum (Liquidambar styraciflua)
- Bald Cypress (Taxodium distichum)
- Winged and Smooth Sumac (Rhus copallinum & Rhus glabra)
🌼 Shrubs
- Beautyberry (Callicarpa americana)
- Winterberry (Ilex verticillata)
- Southern Arrowwood (Viburnum dentatum)
- Southern Wax Myrtle (Myrica cerifera)
- Blueberries (Vaccinium spp.)
- Raspberries (Rubus spp.)
🍃 Perennials
- Black-eyed Susan (Rudbeckia hirta)
- Swamp Milkweed (Asclepias incarnata)
- Purple Coneflower (Echinacea purpurea)
- Boneset (Eupatorium perfoliatum)
- White Snakeroot (Ageratina altissima)
- Blue Vervain (Verbena hastata)
🌾 Grasses and Groundcovers
- Little Bluestem (Schizachyrium scoparium)
- Switchgrass (Panicum virgatum)
- Big Bluestem (Andropogon gerardii)
- Muhly Grass (Muhlenbergia capillaris)
- Wild Strawberry (Fragaria virginiana)
🍇 Vines
- Wild Grape (Vitis rotundifolia, including Muscadines and Scuppernongs*)
- Purple Passionflower (Passiflora incarnata)
- Virginia Creeper (Parthenocissus quinquefolia)
- Coral Honeysuckle (Lonicera sempervirens)
Clay gets a bad rap, but it’s a vital partner in the garden. When we embrace its unique qualities, work with native plants, and allow nature to do its thing, clay transforms from a challenge into a gift.
So here’s to clay 🥂: the foundation of our landscapes, the cradle of countless ecosystems, and the unsung hero of soil creation!
I always got frustrated when digging down to the sticky clay, but I see the light, finally, lol! Thank you for giving me a different perspective and relieving my distaste of that thick, heavy, clumpy stuff!