We have a completely enclosed curved 7 x 17ft bed that we would like to plant with groundcover to form curving rows that alternate different, contrasting plants. The idea is to have river rock flowing from a spilled’ pot surrounded by the rows of plants. Our plant selection is based on our location and is black scallop bugleweed and angelinas teacup sedum. My question is how to plant these in rows so that they won’t grow into each other. Will we have to use a divider between the plants to keep them separate and in their respective rows? Is there a better way to plant them?
Again, Thank you so much for your advice!
This is an interesting question because the reality is that most groundcovers want to grow out as they get established and so you are constantly working to keep them in check. Some groundcovers however are more polite than others.
The first recommendation is that you ensure that the groundcovers that you finally choose are not “invasive” or “rapid spreaders”. That will be a red flag that you will be fighting a loosing battle with the plant from the start. The groundcover ideally would be spread by runners (stolons) so you can see them spread and/or have a shallow root system.
How the groundcover spreads will dictate how you keep them separate. If the plant reproduces by roots or rhizomes, you will need to install a root barrier that will be deep enough so that the roots won’t slip under the barrier or a trench that will be deep and wide enough to keep the roots at bay. If they spread by runners (stolons) you will need to remove the runners as they move into the adjacent area. Like all gardening, some remedial removal of errant plants will be required.
You might also consider using a native or non-invasive ground cover. There is a very good guide to alternatives to invasive plants published by the Ontario Invasive Plant Council, which is a great starting point. It contains examples of ground covers for a range of shade and sun conditions: https://www.ontarioinvasiveplants.ca/resources/grow-me-instead/