Help, I have clay soil

Clay soil is typically what we find in new developments and we identify as heavy, yellowish and very soggy when wet. There are only a few advantages to clay soil; and so it is recommended to amend soil for planting landscapes in more favorable growing conditions. There are some plants (listed below) that will tolerate clay though tolerate is not the same as thriving.

Clay contains the finest particles that are actually secondary minerals and are formed by weathering, erosion and oxidation of sand and silt. If 50 % of the soil is clay, then it is considered clay soil.

The disadvantages of clay for plants are:

  1. Poor downward drainage, the soil stays wet and soggy and can become quite compacted and when it dries out can result in big heavy clods that are hard to work with.
  2. The natural occurring gas exchange often cannot occur in clay soils.
  3. Clay is naturally alkaline which makes certain nutrients unavailable to plants.  Often soil PH is between 7-8.5 which is not good for evergreens and other acidic soil loving plants where the best PH range is 4-6.5. Testing soil is important and yearly amending to lower the PH is necessary for certain plants to flourish.
  4. Clay takes longer to warm up in spring.
  5. Last and importantly, roots often cannot penetrate through clay or spread easily which stunts growth.

The positive is that clay soil is high in nutrient reserves. Ideally then it is best to dig out clay and add loamy type soil around trees, shrubs and other plants in landscapes as well as putting a good layer of topsoil on top for lawns. Clay can actually provide a great base for forming berms and other hard landscape foundations. In other words, it can be a useful element in a landscape or in nature as long as the soil is amended.

Bylands Nursery grows a variety of trees & shrubs that will tolerate clay soil:



Trees    
*Amur Maple *Malus species *Norway Spruce
Sensation Box Elder Black hills Spruce *Scots Pine
*Red Maple (rubrum) Poplar species Bur Oak
Hawthorn (well drained) Willow Japanese Tree Lilac
Ash species (Fraxinus) Lindens Elms
     
Shrubs:    
Amelanchier (Saskatoon berry) Chokeberry (Aronia) Common caragana
*Pagoda Dogwood Red Osier Dogwood Dwarf honeysuckle
Wolf Willow Winged Burning Bush *Junipers
Honeysuckle  Potentilla Sumac
Alpine Currant Willows Snowberry
Lilac species Nannyberry Cranberry (Viburnum)
Spirea    
     
Perennials/ Grasses:    
Hostas Bee Balm Golden Rod
Coral Bells Yarrow Daylily
Heavy Metal Switch Grass Coreopsis Sea Holly
Purple Coneflower Bluestem Grasses Sedums
Asters Russian Sage Black-eyed Susan
Prefers Acidic soils *    

 

When amending soil in clay, it is best to do a large area because the roots of plants can have a difficult time transitioning from the amended soil to clay. The best way to amend the soil is with coarse organic soil/compost and coarse builder’s sand for drainage. The use of fine sand is not recommended as that can create a concrete like situation.

The healthiest finest looking plants can soon struggle if they are not given the appropriate soil conditions for drainage, gas exchange, nutrient availability, and root penetration. If clay is the only option, it is a good idea to check with experts for suitable plants and amendments so that your landscape thrives for years to come.

Happy Gardening!

 

For more ideas ask your local garden center professionals and make sure you follow us on FacebookTwitter,YouTubeInstagram and Pinterest for other tips and hints.

 

 Guest post by Darlene - Bylands Account Representative

I grew up on a farm near Lloydminster and also grew up learning to garden. For some reason pulling weeds from around vegetables and flowers was a source of solace and accomplishment. I was a single mom by the time I attended Olds College to pursue a career in Horticulture and Floriculture. Nature and hands on work, including at Bylands, has been the best school for learning ever since.  Love to travel and always want to live a healthier lifestyle. Plants, people and Nature continue to play a big role in that. I love attending Oilers games with my nephew.

Photo credit header: Kitty Terwolbeck Natural formed brick path via photopin (license)