8 Ornamental Plants that Grow in Clay Soil
Clay soil can be an ideal place to plant ornamental plants, as long as you adapt their condition and make it a comfortable habitat. Certainly, this kind of soil is not friendly to every species; but it’s also true that a few shrubs and flowers can thrive in it.
At first glance, heavy clay soils look dehydrated, fragile, and brittle. However, with proper drainage and special fertilizers, you can achieve a ground that’s suitable for gardening and horticulture.
Of course, it’s necessary to choose certain plants and provide them with suitable care. So, what varieties are we talking about? Below, we’ll reveal them.
The features of clay soil
Clay soil is reddish and cracked. The main peculiarity of these soils is the proportion of clay they contain, in greater quantity than silt and sand, the other components of heavy soil.
They retain enough water, but their “micropores” tend to become saturated, which interferes with ventilation and causes waterlogging.
A chapter in the book Advances in Agronomy comments on the characteristics of clay soil, such as the demand for lime, swelling when wet, and shrinkage when drying. They also mention the delay to warm up in the spring, moisture in winter, and how powerful this type of soil is in keeping plants from suffering from drought, although it only provides them with half of the liquid it may store.
Clay soils in gardening
Clay soils are not 100% amenable to gardening. However, with a proper nutrient supply, they can be corrected. Compost, coarse sand, and diatomaceous earth also promote their structure.
According to a Utah State University publication, it’s necessary to apply irrigation water at a slow rate and over long periods in areas with clay soil, so that it doesn’t run off. They suggest 1 inch of water per 1 foot of depth – once it receives the liquid, it takes a long time to dry.
Thanks to its calcium content, gypsum is another element used by gardeners to loosen the crust and tight density of clay. As for aeration, it’s a good idea to incorporate coarse forms of organic matter, such as degraded sawdust and chopped leaves, as they benefit the microorganisms essential for turning compacted soil into fertile soil.
Clay gardens are demanding in terms of physical labor. However, they can pay back with some beautiful results.
Plant species whose roots are shallow do best in clay plantings.
Decorative plants that grow well in clay soils
Decorative plants that do well in clay soils are those that are drought tolerant since they don’t require the soil to be thoroughly prepared in its top layer. However, some aquatic plants lend themselves to growing in clay soils. For example, they include the following:
- Japanese lily
- Elephant ear
Other decorative plants perfect for clay plots are the ones we’re now going to take a closer look at.
HortScience reports that lilies, genus Hemerocallis, prefer moist soils, but do not reject clay soils. They thrive in soils with a pH between 6 and 8, ideal for their purple, yellow, and red hues. They don’t require meticulous maintenance and their flowers bloom only one day when they can take advantage of the sun.
In marshy clay or a drier one, aronias (featured in the cover photo) develop without problems. They do not need constant watering, although the young plants of this species do “ask” for hydration a couple of times a week. All varieties can be nourished with compost.
The leaves are distinguished by their golden, yellow, and orange range; their fruit is a purplish-black edible berry. They grow on large trees or medium-sized shrubs.
Research reported in the Journal of the Saudi Society of Agricultural Sciences indicates that providing certain amounts of boron in silty clay soil favors sunflower production.
These flowers, famous for their splendor and the seeds they offer, survive in full sun and in conditions that include heavy soils. Among the species that are adapted to these crops are the false sunflower or Helianthus x laetiflorus, the swamp sunflower or Helianthus angustifolius, and the buckeye or Heliopsis helianthoides.
Some bulbs, such as peonies and Liatris, for example, survive in heavy soils. These are easy-to-grow plants that bloom once a season, in mid to late spring. These plants display different colors, sizes, and shapes.
Well-drained, asters work in clay and somewhat acidic soils. Furthermore, the palette of this species ranges from purple, blue, pink, and white. They also appreciate being in full sun or some shade, for late summer and late fall bloom.
6. Buttonbush bush
Its flowers resemble a pincushion, striking amidst the lush green leaves. They are adapted to moist clay soils, as well as those with periodic hydration.
7. Black-eyed Susans
Rudbeckia hirta is the scientific name for black-eyed Susan, an elegant wildflower and perennial suitable for heavy soils. This variety of daisies exhibits golden petals surrounding a black center.
They’re perfect at attracting bees and other pollinators. Thus, the more moisture the soil retains, the more they will spread.
The U.S. Department of Agriculture notes that this species thrives in clay soils with light to moderate to dry moisture. The must for it to survive is a pH of less than 6.8.
This variation of the Hydrangeaceae family sports quite decorative foliage, thanks to its deep green, oval-shaped leaves with serrated edges. Its flowers are violet, blue, and white.
Hydrangeas are propagated by cuttings. They are popular in the field of ornamentation, are resistant to cold, and need moderate watering.
The University of Georgia notes that, in clay soils, these plants grow well, thus, boosting the soil with homemade manure, mushroom compost, and ground pine bark chips. On the contrary, they advise against supplying peat, due to accelerated decomposition.
How to improve the quality of clay soil for growing ornamental plants
In order for ornamental plants to do better in clay soils, it’s a good idea to have artificial drainage and to add lime to dissolve lumps. This is known as a soil amendment and consists of working the plot until it has a lighter texture.
In general, if you’re planting ornamental species in this type of soil, it’s advisable to ask nurseries for specific specimens for clay areas. Get advice on the ideal fertilizer, as well, and find out if what you want to plant is a plant that requires other specific types of care.It might interest you...
All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.
- Black-eyed Susan. Departamento de Agricultura de Estados Unidos. https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_ruhi2.pdf
- Browne M. Hydrangea: A Southern Tradition. Universidad de Georgia an Ft. Universidad Estatal del Valle y Departamento de Agricultura de los Estados Unidos. http://www.walterreeves.com/uploads/pdf/hydrangea.pdf
- Ezzahra N, Fouad A, Houssa A, Kacem M, Khalid D, Saad D. Respuesta del girasol al suministro de boro cuando se cultiva en un suelo arcilloso limoso. Revista de la Sociedad Saudita de Ciencias Agrícolas. Vol. 19. Núm. 1. pp. 81-86. Año 2020. https://www.sciencedirect.com/science/article/pii/S1658077X1830119X
- Griesbach R.J. Hemerocallis L. ‘Chesapeake Belle’. HortScience. Vol. 39. Núm. 1. pp. 190-191. Años 2004. https://journals.ashs.org/downloadpdf/journals/hortsci/39/1/article-p190.pdf
- Jardinería en suelos arcillosos. Universidad Estatal de Utah. https://forestry.usu.edu/news/utah-forest-facts/gardening-in-clay-soils
- Suelos arcillosos. Avances en agronomía. 1994. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/clay-soils