Our recommendations for the best plants for clay soil are Miss Kim Manchurian Lilac and Hemerocallis Cranberry Baby Daylily. Clay soils often challenge gardeners and nurseries because they are heavier and more difficult for plant roots to penetrate. They have their good points too like their tendency to be rich and fertile. Read on to learn which plants will fare well in clay soils.
- Our Top Picks for the Best Plants for Clay Soil
- What You Need to Know about Soil Types
- Clay Soil Benefits and Challenges
- Plant Care with Clay Soils
- Choosing Plants for Clay Soils
- Our Recommendations: Miss Kim Manchurian Lilac and Hemerocallis Cranberry Baby Daylily
Our Top Picks for the Best Plants for Clay Soil
What You Need to Know about Soil Types
Horticulturists group soils by their texture from particle size. There are three sizes that include sand, silt, and clay. Clay is the smallest particle. That means it can compact into tight masses that leave little room for air circulation. Clay is most prevalent in the subsoil rather than the topsoil which typically contains more of the other particles in addition to organic matter.
You’ll have no trouble identifying a clay soil. If you take a handful of moist soil in your hand, it’ll form a ball that will retain its shape. Sand, of course, will flow through your fingers freely and will not form a ball unless it’s completely saturated. Silt falls somewhere in between. Imagine how water and air will permeate to give you an idea of how a plant will manage.
The soil type will also give you an idea of the fertility of a soil. If a soil drains fast, the nutrients it contains will leave with the water. That opposite is true with denser soils like clay. The thing to remember is that soil type impacts plants in several ways and makes gardening differ accordingly.
Clay Soil Benefits and Challenges
The problem with clay soils is that they can compact under pressure. That can pose a barrier for the delicate roots of new plants to penetrate. However, the cons of this soil type also translate into some benefits. You will need to take some different care measures to minimize the negatives and accentuate the positives.
Benefits of Clay Soils
Clay soils exceed at retaining nutrients so that gardeners don’t have to fertilize them as much as other soil types. They are a boon for plants and grasses that prefer fertile soils. The one exception is nitrogen which you may have to add to the soil. You can improve soil quality by adding organic matter which is a good practice for most gardens, anyway.
For clay soils, it is essential. It will create the necessary space for circulation. It will also lighten soils to prevent them from compacting. You can use several types of materials to make soils more plant-friendly. Peat moss, leaf mold, and sawdust offer excellent choices. You should plan on a 1:2 ratio between the amendment and the clay soil.
Cons of Clay Soils
You’ll need to take care when tilling clay soils especially if they’re wet. These soils compact which can reduce air circulation. They also form clods easily which can further exacerbate these conditions. Therefore, you shouldn’t walk or roll heavy equipment over wet clay soils. The cons of clay soils play a major role in determining the best plants.
Clay soils ask a lot of plants. With an increased risk of waterlogging and soil compaction, there’s a lot of things that make it more difficult for plants to succeed. Avoid plants that specify a preference for well-draining soils. Unless you amend your soils with plenty of organic matter, they won’t do well in these soils.
Likewise, some plants won’t thrive in fertile soils as contrary as that may sound. Your best success with plants will come from matching the conditions with the plants. Soil drainage and fertility are critical factors that will decide if a plant survives and thrives. While you can make some changes, your maintenance is less if you start on an even keel.
Plant Care with Clay Soils
Gardening basics for plants that can succeed in clay soils are ones that can tolerate the conditions that are typical for them. That means plants that can handle compacted soils with reduced air circulation. This condition carries risks as it can leave plants vulnerable to root rot. Your plants have to be hardy enough to survive in conditions that could spell trouble for other plants.
This video from Texas A&M AgriLife Starr explains how to identify different soil types based on its texture.
You might see the handwriting on the wall by now. Watering will present an issue with clay soils simply because they drain slowly. With sandy soils that drain well, watering isn’t much of a problem. The risk of waterlogging is virtually nonexistent in drained soils. That’s not the case with clay soils. Instead, you’ll need to water plants in these soils slowly, so water has sufficient time to drain.
As a general rule of thumb, you’re looking at about an inch of water per one foot of soil depth. If you water too quickly, it will simply run off, leading to erosion and other problems downstream. The reverse is also true. Clay soils are slow to dry out. You’ll likely find that you’re watering them less often than sandy soils which drain quickly.
Choosing Plants for Clay Soils
Water tolerance is, therefore, critical to choosing plants for clay soils. Many plants and trees have evolved under these conditions and will do quite well. The names of some of these varieties provide clues to their tolerance. Think river birch, bald cypress, and swamp white oak. These plants can handle the low oxygen conditions that often accompany clay soils.
Our Recommendations: Miss Kim Manchurian Lilac and Hemerocallis Cranberry Baby Daylily
Perhaps as a reward for having difficult soil conditions, we leaned toward plants that would stand out in our garden. All our choices will handle heavy clay soils. We narrowed our focus to the ones that would offer the greatest color to our landscape. To cover all bases, we chose a shrub and a flower to fit most landscaping designs.
The Miss Kim Manchurian Lilac has a lot of showstopper qualities. Its color is gorgeous. And its scent is heavenly. This lilac stood for us because of its compact size. With a height and width up to seven feet, it does take up the large amount of real estate that other lilac demand. It can tolerate a wide range of zones from 3 to 8, making it a good overall choice.
We fell in love with the stunning color of the Hemerocallis Cranberry Baby Daylily. It’s not often you come across a flower with such vibrant colors. It is a hardy plant, able to tolerate Zones 4 to 10. Its rich green foliage is an eye-catching backdrop to its dark rose blooms. And the flowers are edible to boot!
Just because clay soils are difficult, it doesn’t mean that you need to skimp on choosing plants that pack a punch. Our selections offer dramatic colors and a bit of class for any garden. Their wide range of hardiness zones speaks to its ability to tolerate a broad spectrum of gardening situations. Any of our picks would make an excellent choice. Other plants listed for clay soil are prairie dock, viburnum, coreopsis, baptisia, and ornamental grasses.