Planting Between Pyramid Cedar


Front of house, under a maple tree, against sandy soil foundation. Previous try’s included Annabelle hydrangeas, bobo hydrangeas, and now limelight’s…. all have not done well. Colour palette is rose. Other plants include, potentillia(white) PeeGee tree, burning bush, day lily(dusty rose) berburis and lime green hosta.


Before deciding on something else to plant between the pyramid cedars, I suggest that you try and figure out why several of your plants have not done well in that spot.

The Toronto Master Gardeners have prepared a Gardening Guide, “Selecting the right plants for your organic garden”, which discusses factors to consider when selecting plants for your garden, including whether the plant is hardy to your gardening zone, soil type and whether the soil retains moisture, ideal light conditions, the type of soil it requires, and how neighbouring plants may affect one another.

It is not clear from your note whether all the plants you mention have fared poorly this season, or just the hydrangeas.  All the plants you mention should be in well-drained soil that is enriched by compost or other organic matter.  You may want to discuss with your local nursery whether the sandy soil you mention may be affecting the plant health – water may seep right through the top (sandy) layers of the soil, not remaining long enough to for the plant roots to absorb.  One issue, too, might be that it’s been a hot dry summer in much of Ontario, which can certainly make plants unhappy!

It is not clear whether the spot in your garden receives full sun or part shade – there seems to be a lot of shade in the grassy area, but you mention a few plants that require full sun.  It is important both to determine why some plants did not do well, while others may have thrived (if any did – this is not clear from the information you provided).  Consider the following factors:

  • The Hydrangeas: These plants generally require lots of water and some require full sun (e.g., Bobo and Limelight hydrangeas, which also are happiest if protected from hot afternoon sun) or partial shade (e.g., Annabelle hydrangeas).  The PeeGee hydrangea also likes full sun.  If you prune your hydrangeas, all the above bloom on new wood, which means you can cut them back in the fall, winter or as late as early spring – before new growth emerges.  If you cut them back too late in the growing season, they won’t bloom — this could be a reason they did not do well.
  • Potentilla: this shrub also likes full sun.
  • Burning Bush: likes full or partial sun and does well in most soil conditions.
  • Daylilies: these perennials can compete for water and nutrients if planted directly under trees and shrubs, so if they are too close to your cedars or the maple, may not be doing well. They do best in full sun but tolerate light shade, and flowers stay fresh longer if shaded during hottest part of day.
  • Berberis (Barberry): can grow in full sun or partial shade and tolerates almost any soil that is well-drained.
  • Hostas: generally grow in part to full shade.

Once you have reviewed the Guide, there are additional detailed Guides on many topics on our Toronto Master Gardeners website that will be relevant, and include many suggestions for perennials to choose – e.g., perennials for full sun, shade, sandy soils, dry or drought, etc.

All the best with your garden!