By Carol Anderson, Master Gardener

When I recently purchased a new home, I was too preoccupied with the beautiful lake view to truly notice some of the gardening challenges that lay ahead for me. Once I began the process of itemizing what garden treasures I had, I became acutely aware of the gardening style of my predecessor … a style that included utilizing ground cover plants to “fill in” raised beds … and apparently the faster they spread, the better!!! The challenge I have ahead of me is the removal or containment of numerous ground covers that have invaded every inch of the property. In this segment I will briefly touch on the management and/or extraction of 4 different commonly used ground covers that range from just “annoying” to outright invasive.

Chameleon Plant,  Bugleweed, Yellow Archangel, Periwinkle

Bugleweed (Ajuga reptans):

Although not considered invasive, Bugleweed can become problematic if left on its own without management, as it has a tendency to spread into adjacent lawn areas. I personally like the dark burgundy-red foliage, however, on my property it has spread across an entire garden and into the lawn. Bugleweed spreads through “shallow” underground runners with new baby plants popping up at the end of the runners. As a result, it is not impossible to remove nor contain. In the spring, I will be digging up the new plants all around the edge of the garden border and installing edging below the garden surface to stop the spread into the lawn. Periodic thinning (by digging up and removing some of the parent plants in the clump) will help to keep it manageable as well.

Yellow Archangel or Golder Deadnettle (Lamium galeobdolon):

Although Lamium is a common ground cover used in many garden applications, it is invasive in Ontario. It has infested natural areas and will out-compete native groundcovers in the wild. Lamium  spreads by plant fragments, rooting along the surface on the stems (see photo below). However, it also can spread by seed which can then be carried into natural environments by birds.  For this reason, I will be completely removing it from several of the large shade gardens on the property and replacing with native species. Luckily it spreads along the surface and can be removed by mechanical means. This will be another spring project in the garden and once fully extracted, I will begin investigating other options such as anemone, wild ginger, bunchberry dogwood and ostrich fern for the heavily shaded areas of the garden.

Periwinkle (Vinca minor):

Periwinkle is a very common shade groundcover used by gardeners. It is considered to be invasive as it spreads quickly given the right climatic conditions. It poses a threat to natural biodiversity as it can out-compete other forest understory plants. However, because it spreads by rooting along the stems on the surface of the ground (stolons), it can be contained through proper management of the plant. I plan to dig up the roots and plants and cut back the excessive amount of Periwinkle in the garden, interspersing it with other shade loving plants. This will require ongoing observation and management on my part. 

Chameleon Plant (Houttuynia cordata):

Avoid, avoid, avoid. Although an attractive groundcover, chameleon plant will invade your garden and lawn very quickly and became completely unmanageable. It is a non-native that spreads by a highly dense deep underground network of roots (rhizomes)(see pics below). Even a small segment of root left behind will live and spread for years to come making eradication very difficult. This fall, I began digging around the perimeter of the patch well outside of where the plant is visible on the surface. I dug down 12 inches and was still running into dense mats of roots!!!  I then sifted through the soil to remove all plant segments and put the soil back. At this point I have just begun the process of eradication (Step 1) and will keep you posted on my progress in my blog next spring. If I need to resort to solarization (using the sun’s heat to kill the plants under plastic), then this might be the next step for me. Stay tuned!!!

If you are a fan of using plants as groundcover in your gardens and raised beds, proceed with caution. If it spreads quickly, filling in bare areas, then it is likely invasive at worst and hard to manage at best. Proceed with caution and be prepared to observe and manage the groundcover to avoid the situation where the plant literally takes over the garden, eliminating all other species. In addition, there are many native Ontario alternatives to the traditional groundcovers…try them out and enjoy (https://www.inournature.ca/native-groundcovers).