Native perrenials for full sun clay soil

(Question)

Hi Toronto Master Gardener! Any suggestions for low and medium height perennials that are great for very heavy clay soil in full sun? Also any suggestions for year-round colour?

Thanks!

(Answer)

Congratulations on wanting to grow native. The benefits of gardening with native plants are many including: attracting native pollinators and birds, easy maintenance and helping to conserve our natural heritage for future generations.

Plants which are able to thrive in clay soil are extremely hardy, and their root systems are strong enough to break through the heavy clay soils and are able to handle the compaction that can occur. Clay soils absorb water very slowly and retain water for a long time. When dry, they harden and become extremely difficult to work. It is always advisable to improve the texture and structure of your clay soil by adding a couple of inches of organic matter, such as mulched leaves, compost, wood mulch. Improving the texture and structure of your clay soil you will be able to plant even more species.

Here are a few that would work:

Bee balm                      Monarda didyma

Big BlueStem              Andropogon gerardii

Little Bluestem           Schizachyrium scoparium

Black- Eyed Susan     Rudbeckia hirta

Blue Vervain                Verbena hastata

Boneset                         Eupatorium perfoliatum

Butterfly Weed            Asclepias tuberosa

Cup Plant                     Silphium perfoliatum

False Sunflower           Heliopsis helianthoides

Blazing Star                  Liatris spicata

Golden Alexanders       Ziza aurea

Goldenrod                      Solidago spp

Compass Plant              Silphium laciniatum

Ourple Coneflower       Echinacea purpurea

The North American Native Plant Society also has an excellent site with a Canadian section for northern gardeners at https://www.nanps.org/

Other sites with downloadable brochures which could be helpful to you are:

How to Select and Buy Native Plants

Why grow Native Plants by The Canadian Wildlife Federation

These Native Plants Love Clay Soil by Landscape Ontario

Lastly, 100 Easy-To-Grow Native Plants for Canadian Gardens by Lorraine Johnson is an excellent resource