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?
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:
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.
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!
Need more help? Contact our plant experts for advice at customer-support.naturehills.com.
