By Erin Marissa Russell
Want to learn about plants that won’t just survive in clay soil—they’ll thrive in it? If your garden has soil that leans more toward clay than it does toward sand or loam you may think you’re facing a big job to get ready for planting. (And just in case, if you aren’t sure what kind of soil you have in the area where you’d like to garden, there’s an easy way to test your own soil conditions that just requires a mason jar to get you on the right track.
Options for Gardening When You Have Clay Soil: Amendment and Raised Beds
Of course, it’s true that the quality and conditions of your garden’s topsoil have a major effect on the health of the plants you’ll grow in that garden. Soil that contains more clay can be heavier and thicker than some plants prefer, and it doesn’t offer the level of water drainage that many gardeners’ favorite plants need to grow healthy and strong.
Amending clay to make it the ideal topsoil for standard gardening is a big project that requires some knowhow along with a good deal of calculation and preparation, not to mention quite an investment when it comes to the supplies, time, and labor you’ll invest. But if you want to grow plants that need that a classic gardening soil to do their best, the investment soil amendment requires is well worth its rewards. Attempting to cultivate plants in a soil that isn’t right for them comes along with lots of drawbacks and is unlikely to be ever be truly rewarding.
When gardeners add amendments to improve their clay-based soil, they mix in a blend of compost and sand to lighten the soil texture and provide drainage, making sure to supplement the additional soil with fertilizer.
Gardeners who don’t want to amend their soil but want the freedom to grow plants that need more loam can also opt to build raised beds right on top of their existing soil. The raised beds can then be filled with soil that’s ideal for whatever crops will be planted there. If you decide to go that route, our Ultimate Guide to Raised Bed Gardening will guide you through what you need to do to build and install your own raised beds.
Benefits of Gardening in Clay-Based Topsoil
However, there are lots of flowers, shrubs, and vegetables you can enjoy growing right now that will let you see success with in the clay-based soil you already have. Generally, plants with shallower root systems can get the nutrition they need from soils that have more clay, and these plants won’t be too bothered by the extra moisture a clay-based soil provides. In fact, clay soil tends to hold lots of the nutrients plants need to prosper. Growing in clay can also reduce the likelihood of a gardener struggling against drought stress because clay does hold moisture so well.
Drawbacks of Gardening in Clay
People who choose to plant in clay-based soil should be aware that clay is notorious for requiring more of the gardener physically. After all, it takes a little extra strength and energy to toss the added weight of clay soil around with a shovel. That sticky, moist consistency that clay is known for also means you may need to stop working and clean your tools more frequently than those working in other soil types.
However, the additional work clay requires is a temporary drawback gardeners can power through that doesn’t present any hazards to plants grown in clay. The one exception is if you encounter a light-colored, cement-like layer of soil on the surface or just underneath it that’s practically impossible to work with. This soil, heavy in calcium carbonate or lime, is called caliche. If your gardening area is made up of caliche, you will absolutely need to put some time in to amendment before planting, as roots can’t pass through this cemented layer.
The Best Plants for Clay Soil Gardens
For the gardener at work, sandier and loamier soils do come along with the benefits of both lighter weight and less resistance to digging than clay. However, if you’re willing to put in a bit of elbow grease in the planting phase, you’ll get gorgeous results with the plant varieties we cover here. So get ready to start a wish list: The plants we’ll present in this article are right at home in clay. In fact, these plants will flourish in your clay-based soil without requiring a lot of extra work from you to get the topsoil ready.
The arborvitae class of plants is made up of a few different varieties of tall, pyramid-shaped trees or shrubs with needles and cones, any of which will grow tall and strong in clay. Arborvitae are hardy up to USDA growing zone 3. Choose among American or eastern Arborvitae (Thuja occidentalis) and giant arborvitae or western red cedar (Thuja plicata). The smallest arborvitae varieties are around three feet tall, while the giants can grow up to 70 feet tall and 25 feet wide, so select the type of arborvitae you’ll grow to suit the space you’d like to fill.
Also called chokeberry, aronia in springtime features white flowers with powdery pink centers that develop into purplish-black edible berries as the season progresses. In autumn, foliage comes to life as the leaves blaze in shades of yellow, orange, and gold. Aronia is available as a large tree, moderately sized shrub, or in smaller Low Scape varieties, including Low Scape Mound, which is perfect as a groundcover. Plant aronia or chokeberry in sun or partial shade and feed with compost, and it will be happy in soil ranging from the boggiest clay to the driest sand. Once plants mature, you don’t need to water them as often, but you’ll need to hydrate younger plants once or twice a week.
Attract butterflies, birds and bees with the wide range of colors of asters. Asters are perennials and bloom late summer to fall. In hot climates, try growing asters as biennials or annuals. Read more here about growing asters.
Blazing Star (Liatris spicata) and Prairie Blazing Star (Liatris pycnostachya)
Gardeners who grow liatris flowers like Blazing Star are treated to spires of violet flowers from two to five feet high. Blazing Star flowers are hardy in USDA growing zones 4 through 9.
Black-Eyed Susan (Rudbeckia hirta)
Black-eyed Susans are American wildflowers with black centers surrounded by cherry goldenrod-colored petals and are also called coneflowers, Gloriosa daisies, or their official name, Rudbeckia hirta. The more than 30 types of black-eyed Susans can be categorized as short-lived perennials, annuals, or biennials, depending on the variety and where they’re being grown. Most of the perennials are suited for USDA growing zones 4 through 7.
Bluestar is cultivated for its star-shaped flowers that are the same blue as a pair of faded jeans. These flowers are hardy in USDA growing zones 3 through 9.
Buttonbush is named for its pincushion-shaped flower clusters, which are sprinkled like dots throughout its vibrant green foliage. This shrub attracts 24 species of birds as well as butterflies to the garden. It grows five to eight feet tall and is hardy to USDA growing zones 4 through 8. In addition to tolerating moist clay soil well, the buttonbush will also grow without impediment in alkaline soil or areas with periodic flooding.
Coneflower is known for being easy to grow. Its cheerful pink flowers with a daisy-like shape droop down from the orange blaze-colored centers and require almost no care. Gardeners do well with coneflower in USDA growing zones 3 through 9.
Daylilies are a perennial favorite requiring little maintenance or tending. Gardeners across the country can grow daylilies, but they’re most at home in USDA growing zones 4 through 9.
Dogwood trees are known for their gorgeous, old-fashioned white blooms that emerge in spring. In summer, these trees boast high-gloss green leaves that turn to fiery fall colors as seasons change to autumn. Gardeners can grow dogwood trees in partial shade with success in USDA hardiness zones 5 through 9. The trees grow best when treated to some mulch (pine needles, compost, or mini bark mulch) and soil pH level measures between 5.2 and 6.0. (You can do your own pH testing if you aren’t sure of your garden soil’s level.)
The forsythia shrub ranges between three and nine feet tall, with delicate yellow blooms in springtime. It’s at its best in USDA growing zones 4 through 9 for gardeners with soil that has a pH level between 6.8 and 7.7.
Fountain Grass (Pennisetum alopecuroides)
Deer-resistant fountain grass doesn’t ask a lot of the gardener. It stands at three feet tall by three feet wide when mature and performs best in USDA hardiness zones 6 through 9, though it can be babied through zone 5 in a protected location.
Sea Holly (Eryngium)
These unusual-looking spiny flowers in periwinkle blue are all varieties of Eryngium plants and range from two to six feet tall. There are varieties of sea holly that thrive in USDA growing zones 4 through 10.
There are 100 different kinds of spirea shrub out there for gardeners to choose from. Spirea can fill a space from two to 10 feet tall and two to 20 feet wide with blossoms of white, pink, red, or yellow in spring or summer, depending on the variety. Grow in USDA hardiness zones 3 through 8.
There’s nothing prettier than a field of sunflowers. These garden giants can stretch up to 15 feet tall and do their best in warmer climates. You’ll want to choose perennial varieties, which come back year after year and are a bit smaller than annual sunflowers. Choose from false sunflower (Helianthus x laetiflorus) for USDA zones 5 through 9, ox eye (Heliopsis helianthoides) for zones 4 through 9, or swamp sunflower (Helianthus angustifolius) for growing zones 6 through 9.
A Gigantic List of More Shrubs, Trees, Flowers, and Herbs to Grow in Clay Soil
Didn’t find what you were looking for in our list of highlights above? Here are some other plants to consider for gardens with clay-based soil.
- Big Bluestem (Andropogon gerardi) or Little Bluestem (Schizachyrium scoparium)
- Birch tree
- Butterfly Weed (Asclepias Tuberosa)
- Canadian Wild Rye (Elymus canadensis)
- Canna Lily
- Compass Plant (Silphium laciniatum)
- Coral Bells (Heuchera)
- Cup Plant (Silphium perfoliatum)
- Cypress Tree (Taxodium distichum)
- Drooping Coneflower (Ratibida pinnata)
- Eucalyptus tree
- Eulalia Grass (Miscanthus sinensis)
- False Indigo (Baptisia)
- Goldenrod (Solidago)
- Indiangrass (Sorghastrum nutans)
- Lilac (Syringa vulgaris)—For well-draining clay only
- Mountain ash tree (Sorbus)
- New York Ironweed (Vernonia noveboracensis)
- Perennial Geranium
- Pine tree
- Rose of Sharon
- Russian Sage
- Sedum “Autumn Joy”
- Smooth Hydrangea(Hydrangea arborescens)—For well-draining clay only
- Summersweet (also known as Clethra alnifolia or Pepper Bush)
- Sweet Flag (Acorus gramineus)
- Switch Grass (Panicum virgatum)
- Tickseed (Coreopsis)
- Viburnum Tree (All That Glitters, All That Glows, Brandywine, or Lil Ditty varieties—For well-draining clay only
- Wild Bergamot, Bee Balm (Monarda fistulosa)
- Winterberry Holly (Ilex verticillata)
- Yarrow (Achillea)
- Yucca filamentosa (also known as Adam’s Needle)
Perhaps you’ve decided to work with the clay soil you’ve got for the rest of your foreseeable gardening future, or maybe you’re just looking for some temporary options that can thrive in your clay soil while you put some time into topsoil amendment or installing raised beds. Whatever your end goals, when you choose plants from this list to grow in your clay soil, you can rest assured that your soil type will be working toward and not against the success of your garden, and your work will result in healthy plants you can be proud of.