Which soil to use for native garden in dry shade

(Question)

I am beginning work on what will be a native plant garden in the west end of toronto. First I will remove a layer of asphalt and up to 12 inches of gravel. The soil underneath is sandy and the area is fairly shady. I don’t want to dump yards of triple mix or anything like it on top of the sand but to rather mimic the sandy soil already there. How would you suggest I do this? Any advice about what species would thrive in these conditions would also be helpful

(Answer)

There are a few issues to consider when implementing your proposed garden plan besides the effort and expense of removing the asphalt and gravel; see below for a short list:

  1. Toxicity of soil from chemical leaching or runoff.
  2. Fertility of soil.
  3. Soil pH.
  4. Abundance/lack of microorganisms.
  5. Soil texture.
  6. Soil compaction.

After removing the top layers and getting to the soil underneath, I would suggest you get a comprehensive soil analysis test done to find out what you’re dealing with before you amend it in any way.  This will give you a really good idea of any problems or shortfalls you need to address before making further decisions on planning your garden.

In general, sandy soil drains quickly and lacks nutrients, so it may be that you will need to add organic material for moisture retention and as plant food.  Certainly, triple mix would help with this but so too would adding well rotted compost, sheep manure or mushroom compost.  You do not state how big the area is, but the city of Toronto offers free compost in the spring so collecting this may be a cost effective way of addressing the nutrient and moisture retention issues if you want your plants to get established and thrive.

Below you will find a short list of native plants for dry shade to get you started:

  1. Wild Ginger – Asarum canadense
  2. White Wood Aster – Eurybia divaricata
  3. Pennslyvania Sedge – Carex pensylvanica
  4. Bottlebrush Grass – Elymus hystrix
  5. Large Leaf Aster – Eurybia macrophylla
  6. Spotted Geranium – Geranium maculatum
  7. Woodland Sunflower – Helianthus divaricatus
  8. Canada Mayflower – Maianthemum canadense
  9. False Solomons Seal – Maianthemum racemosum
  10. Purple Flowering Raspberry – Rubus odoratus
  11. Zigzag Goldenrod – Solidago flexicaulis
  12. Large Flowered Bellwort – Uvularia grandiflora
  13. Barren Strawberry – Waldsteinia fragarioides

Hope this helps.

13/11/2021