Is vinca a good option to plant a cul de sac?
My dad’s gardener recommended planting vinca in shade under a huge holly on a cul de sac. It will not be able to escape by rhizomes since the cul de sac is surrounded by the road. Is vinca harmless in this case? I recommended planting natives instead and said I thought that planting vinca was worse than doing nothing, but perhaps I am incorrect. I’d appreciate your take.
Vinca is no longer recommended as a groundcover because of its invasiveness in natural areas. It out-competes native plants that are an important part of the ecosystem. http://mdinvasives.org/iotm/jan-2019/
We recommend planting a selection of native plants.
Refer to our lists of recommended plants for shady slopes (https://extension.umd.edu/hgic/topics/native-plants-shady-slopes) and groundcovers (https://extension.umd.edu/hgic/topics/groundcover-list). Look for native plant selections.
Thank you for this information but could you answer my specific question, which is whether vinca is harmful in this specific case. Namely, being planted on a cul-de-sac surrounded by an asphalt road, with no ground cover growing beneath a large holly bush. I submitted a photo.
That's a good question. The chances of the vinca escaping from the island are extremely remote, almost nil. They primarily spread by layering, though they can produce seeds. They are almost never known to spread by seed, however. On the positive side, the vinca would provide a cover, prevent erosion and oxygen. So, it would not be aggressively harmful, per se. It's possible that animals could move a bit of root outside the circle. Or a human, in moving another plant out of the circle, could move the vinca into a potentially harmful area.
However, using vinca instead of a native species means that the area is not an environmental positive. This would be the biggest downside to using the vinca. By planting a native plant instead, your community could use the space to be beneficial to our natural wildlife.
Also, planting something that is not a foreign invasive--such as epimedium which not native yet tolerates dry shade--it would be possible to be more neutral.