Hardy perennials for a shady border

(Question)

Hello
I am looking for advice for a small low border plant that can go beside these hostas. I have tried transplanting myrtle there but didn’t take. It gets stepped on sometimes because the car is parked beside there. The trees there are forsythia.
It gets a couple hours of sun, but changes throughout the summer. Newish soil, good drainage, dryish. I will top off with black mulch. Any suggestions would be appreciated.

(Answer)

Dear gardener,

Your border certainly looks healthy and pretty!

Stepping on plants due to the proximity to the parking is a bit of an issue as it will compact the soil overtime. This compaction will reduce the amount of air in the soil and therefore will kill any plant you place in that area. I would suggest placing some river stones in the transitional area of the border (where the soil meets the driveway) to work as a ‘reminder’ when stepping out.

Given that the bed has good drainage, tends to get dry and is located in shade (full shade is defined as 4 hrs of sun/day), I would suggest the following groundcovers:

  • Periwinkle/myrtle – Vinca minor ( I know you have already tried it but this ground cover takes a little time to get established. After a couple of years it will cover the entire bed!)
  • English ivy – Hedera helix . This evergreen will also take over the bed. It is quite resistant to salt and traffic. I noticed that in the picture, your neighbour already has some coming over the fence.
  • Bugleweed – Ajuga reptans. Purple flowers and darker foliage.
  • Dead nettle- Lamium maculatum. Purple/pink flowers and variegated foliage.
  • Japanese spurge – Pachysandra terminalis. Although it was not available last year, it may be available in the future.
  • Sweet woodruff – Galium odoratum. A very pretty plant with scented white flowers. It will take a bit longer to spread.

One word of advice on the above is that overtime they are all a bit aggressive and will cover the entire bed. Ivy and periwinkle, in particular, should never be planted next to a natural setting such as a woodland or ravine where they can escape and overwhelm native plants.  However, they can be useful garden plants in a controlled setting such as your contained garden bed.

If on the contrary you like the look of soil and clump planting, I may suggest that you can plant some of the following:

  • Low sedges (Carex). Plant in between your lungwort/pulmonaria (please note they are not hostas). Their grassy blades will look quite nice contrasting with the foliage of the lungwort and the forsythia shrubs.
  • Hostas, whose wide foliage will also look nice with the current planting or,
  • Perennial geraniums, particularly big-root geranium, (Geranium macrorrhizum) which can be easily control into clumps.

Lastly, to encourage a good soil structure, reduce weeds and maintain moisture, you may want to add some mulch on this bed and remember to water the plants well as they are getting established.

For further reading on the topic of groundcovers and shade planting, please refer to the Toronto Master Gardeners Gardening Guides:

https://www.torontomastergardeners.ca/index.php/factsheet/broadleaf-evergreen-groundcovers-a-toronto-master-gardeners-guide/

https://www.torontomastergardeners.ca/index.php/factsheet/lawn-alternatives-and-organic-care-of-groundcovers-a-toronto-master-gardeners-guide/

https://www.torontomastergardeners.ca/index.php/factsheet/perennials-for-shade-in-dry-or-moist-areas-a-toronto-master-gardeners-guide/

Happy planting!