Best Plants for Clay Soil Gardens | Nature Hills

Yes, you can have a gorgeous yard even in thick, sticky clay soils…here's how!

What is clay soil and how do you know if you have it?
What can I grow in this clay soil?
Here's Why You Shouldn't Overdo the Amendments in Clay Soils
Top Trees for Clay Soil
Top Shrubs for Clay Soil
Top Perennials for Clay Soil
Landscape Design Tips for Clay Soil

What is clay soil and how do you know if you have it?

If you see long-lasting puddles or cracking after rain, you likely have heavy soil that is composed of at least 40% clay minerals. This is sticky, light yellow, red or brown soil that clumps together in your clenched hand, and stays clumped even if you poke at it.

If you see your soil dry in cracks or crusts, you likely have clay soil. This is very common in new construction areas and around foundations if heavy clay subsoils have been excavated for use as fill dirt.

Dirt is primarily made up of three different materials: silt, clay particles and sand. Organic material is also found to various degrees.

Soil scientists agree that clay soils were deposited by water flowing over rock, causing physical weathering. Clay minerals are actually tiny rocks and crystals that pack together tightly for a nutrient-rich, yet dense soil that doesn't shed water quickly.

The problem with tightly-packed clay soil particles is that most plant roots do best in rich, well-drained, loamy soils that have plenty of air pockets, or macropores. Their tiny feeder roots need to be able to access oxygen, water and micronutrients through these larger-sized pores.

Many plants will actually drown if planted in heavy clay soil, because it tends to stay waterlogged for a long period of time. But not all…some plants at NatureHills.com are perfectly adapted to thrive in clay soils!

What can I grow in this clay soil?

We hear this question a lot…and there are things you can do to improve the physical condition of your clay soil. No matter whether you want to grow plants in the red clays of the Southern United States around the Piedmont; in the thick Casa Grande layered clay horizons of Arizona, or in the expansive clay glacial deposits of the Midwest:

First, choose the right plants to achieve success!
Use a combination of sharp picks to physically break through the heavy layers of sediment; followed by narrow trenching shovels to remove it from your planting hole
Add Nature Hills Root Booster during planting to introduce beneficial soil organisms to the soil in your garden
Apply mulch after planting, but take care to pull it back away from directly touching the stems!
Top-dress existing plants with compost and wood mulch or pine straw
On large properties, you can improve clay soils over time by planting cover crops to loosen the soil structure and add valuable biomass

Here's Why You Shouldn't Overdo the Amendments in Clay Soils

According to the latest plant research, it's best to let your new landscape trees and bushes acclimate directly into your native soil. In fact, respected Horticulturalists are saying that amended planting holes eventually have negative consequences to plant health.

Creating an overly nutrient-rich planting hole will cause the roots to encircle the edges, and discourage outward growth into your native soil. Water also tends to accumulate in the planting hole, especially if you include organic composts in your amended backfill soil.

The clay soil of your yard already retains water; and adding too much compost makes your flooding problems worse. At NatureHills.com, we're on the frontline of the latest thinking in plant science and tests have shown that plants can also drown in overly-amended planting holes surrounded by slow-draining clay.

When installing woody plants, please use Nature Hills Root Booster and your native soil as backfill. You'll achieve far better results over time.

For tender annuals and vegetable plants, use a small amount of textured soil amendments designed to improve drainage during planting, such as: wood chippings, shredded leaves, leaf mold and packaged soil conditioners. Or you can choose to raise them in planting mounds or raised containers filled with loamy topsoil.

Top Trees for Clay Soil

Because clay soils developed along waterways over the long span of geologic epochs, you should select trees that naturally grow along streambeds. Some of these prefer rich, well-drained loam…but are tough and adaptable to handle clay soil, as long as they aren't planted too deeply.

NatureHills.com offers a very large amount of these native species trees, such as:

Linden — symmetrical form, fragrant flower and pollinator value
Purple Robe Locust - fine-textured shade tree with gorgeous spring bloom
Quaking Aspen - slim form, fluttering foliage and fall color
Shagbark Hickory — for texture and edible nuts
Siouxland Cottonwood — seedless, large-scale shade tree and fluttering foliage that catches the light
Swamp White Oak — long-lived specimen tree, wildlife value and fall color
Tulip Poplar — bold foliage and outstanding spring bloom

Top Shrubs for Clay Soil

Like their larger cousins, woody shrubs that tolerate thick, sticky clay soils that hold water are easy-care and handsome. Plant them in informal groupings to bring interest.

Create "living walls" of outdoor rooms with larger varieties; and use the smaller shrubs as groundcover or as a focal point. These beautiful plants grow well even where soil is clay:

Buttonbush — fun flower shape and fragrance
Nannyberry Viburnum — wildlife value and fall color
Ninebark — showy bloom, foliage color and winter interest
Red Twig Dogwood — wildlife value and winter interest
Sweetspire — fragrant bloom and fall color
Upright Red Chokeberry — brilliant berries, fall color, spreading habit
Weigela - arching form, spring bloom and foliage color

Top Perennials for Clay Soil

Many of your favorite tough native prairie plants develop strong taproots that can easily penetrate through sticky, nutrient-rich clay soil profiles. An easy fix for clay soil plantings is our Pocket Garden series:

Spring Pollinator Pocket Garden
Summer Pollinator Pocket Garden

Follow the lay of your land to understand where the water flows. Are you also dealing with low-lying soggy spots where the clay holds onto moisture?

Try a few Rain Garden Pocket Gardens to help filter potentially polluted runoff. Our Horticulture team recommends that you plant them without fretting or worry…they'll naturally grow into the most marvelous drifts.

Spring Rain Garden Pocket Garden
Summer Rain Garden Pocket Garden

Landscape Design Tips for Clay Soil

Even in clay soil, the principles of landscape design hold true. Look for opportunities to bring out the best of your space through repetition, color and contrast between evergreen and deciduous plants.

Wise plant choices will make or break the look of your landscaping. Spend the time shopping our extensive online plant catalog to choose a well-balanced mix that will stay in scale with your home.

The good news? We offer plenty of flowering and fall color accent plants that perform quite well in clay soils.

We also sell raised beds to use if your clay soil is just too hard to handle, or you want to grow vegetables and fruit bushes. Clay soils are no joke…choose your plants wisely and know when to bring in a little help from a raised garden bed!

Frequently Asked Questions

How do you prepare clay soil before planting a pre-planned garden?

To prepare clay soil for planting, start by using a sharp pick to physically break through the dense, compacted layers, then use a narrow trenching shovel to remove the loosened material from your planting hole. Add Nature Hills Root Booster at planting time to introduce beneficial soil organisms that will help your new plants establish in the heavy soil. Finish by applying a layer of mulch around your plants to help regulate moisture and temperature. Most importantly, choose plants that are proven to thrive in clay soils from the start, as selecting the right plants is the single most important factor in your success.

Which types of plants thrive best in a clay soil garden?

Clay soils support a surprisingly wide range of plants when you select varieties specifically adapted to dense, moisture-retentive conditions. At Nature Hills, top performers for clay include tough deciduous trees like oaks and bald cypress, hardy shrubs such as viburnums and native spirea, and deep-rooted perennials like coneflowers, black-eyed Susans, and daylilies. Browse the clay soil plant collections at naturehills.com and filter by your hardiness zone to find trees, shrubs, and perennials proven to thrive in your specific region.

Can clay soil actually support a healthy, productive garden without major amendments?

Yes, clay soil can absolutely support a thriving garden when you select plants that are naturally adapted to its dense, nutrient-rich structure. Many trees, shrubs, and perennials actually perform well in clay because it retains moisture and holds nutrients effectively. The key is to avoid over-amending, which can create drainage problems, and instead focus on choosing the right plants from the start. Browse Nature Hills' curated collections of clay-tolerant trees, shrubs, and perennials to find proven performers for your region.

How do compost and organic matter improve clay soil for a pre-planned garden?

Compost and organic matter improve clay soil by introducing beneficial microorganisms and creating larger pore spaces between tightly packed clay particles, which allows plant roots to access the oxygen, water, and micronutrients they need to thrive. Adding a 2 to 3 inch layer of compost worked into the top 12 inches of your planting area helps break up dense clay and improves overall drainage. Nature Hills Root Booster can be applied at planting time to further establish beneficial soil organisms that continue improving soil structure over time. Start amending your soil in early spring or fall when temperatures are moderate, and top dress with mulch after planting to retain moisture and continue feeding organic matter into the soil below.

Should you add sand or gypsum to clay soil, and do these amendments really help?

Adding sand to clay soil is one of the most common gardening mistakes you can make, as mixing sand with clay essentially creates a concrete-like mixture that makes drainage even worse. Gypsum can help in some limited situations, particularly in sodic clay soils common in arid regions like the Southwest, but it offers little benefit in most average clay soils across the Midwest and South. Rather than relying on amendments to transform your clay, focus on selecting plants that are naturally adapted to thrive in clay conditions, breaking up planting areas with a pick or narrow trenching shovel, and introducing beneficial soil organisms with a product like Nature Hills Root Booster at planting time.

How do you plant perennials and shrubs in heavy clay soil to prevent root rot?

To plant perennials and shrubs in heavy clay soil, dig your hole using a sharp pick to break through the dense layers, then use a narrow trenching shovel to remove the loosened material. Plant slightly higher than grade level so the crown sits above the surrounding soil, which helps prevent water from pooling around the root zone. Add Nature Hills Root Booster at planting time to introduce beneficial soil organisms that improve drainage and nutrient uptake. Finish by applying a 2 to 3 inch layer of mulch around the plant to regulate moisture and moderate soil temperature, keeping it pulled back from the crown to discourage rot.

How do you plant bulbs in clay soil so they drain well and do not rot over winter?

Bulbs planted in clay soil are highly prone to rot because clay holds moisture around the bulb for extended periods, especially during freeze-thaw cycles in winter. To improve drainage, dig your planting hole several inches deeper than the recommended depth, add a 2-inch layer of coarse grit or pea gravel at the bottom, then backfill with a mix of your native soil and sharp sand or a gritty amendment before placing the bulb. In zones with wet winters, consider planting on a slight slope or in raised beds to encourage water to move away from the bulb naturally. For best results, plant spring-blooming bulbs in fall after soil temperatures drop below 50 degrees F, and avoid overwatering or heavily mulching directly over the bulb planting area until the ground is well settled.

How do you fix large cracks that develop in clay soil during hot or dry weather?

Large cracks in clay soil during hot or dry weather are a natural result of the soil's shrink-swell cycle and signal that your soil needs consistent moisture and organic matter over time. Applying a 3-inch layer of organic mulch, such as wood chips or shredded bark, over the soil surface helps retain moisture and regulate soil temperature, reducing the severity of cracking. Do not pour large amounts of water directly into the cracks, as this can cause uneven swelling and damage nearby plant roots. Instead, water slowly and deeply on a regular schedule, and work toward long-term soil improvement by incorporating organic matter each planting season to gradually improve soil structure.

When is the best time of year to plant a pre-planned garden in clay soil?

The best time to plant in clay soil is during spring or fall when temperatures are mild and soil moisture is moderate, typically when daytime temps are between 50 and 75 degrees Fahrenheit. Avoid planting in summer when clay bakes hard and cracks, or in winter when it becomes waterlogged and compacted. In warmer zones (7-10), fall planting is often ideal since cooler temperatures reduce transplant stress and seasonal rains help roots establish before summer heat. Prepare your planting holes in advance with a sharp pick and narrow trenching shovel, add Nature Hills Root Booster at planting time, and finish with a layer of mulch to regulate soil temperature and moisture.

How do you improve drainage in a clay soil garden without rebuilding the entire bed?

Use a sharp pick to physically break through the dense clay layers, then remove the loosened material with a narrow trenching shovel before planting. Add Nature Hills Root Booster at planting time to introduce beneficial soil organisms that help improve soil structure over time. Finish by applying a layer of mulch around your plants to regulate moisture and gradually build organic matter at the soil surface. Focus your efforts on the individual planting hole rather than trying to overhaul the entire bed at once, and prioritize selecting plants that are already adapted to thrive in clay soils.

Pre-Planned Garden for Clay Soils