QUESTION: This vine (in the photo) is growing behind the boxwoods in front of our house. I’ve never seen it before. Is this something I should keep or get rid of?
Get rid of it, if you can. It looks like variegated bigleaf periwinkle (Vinca major), and left to grow on its on, will scramble and snake its way across everything in its path. This plant, considered an ornamental groundcover by some, was brought here from Europe more than three centuries ago.
It has pretty little blue or lavender pinwheel flowers in spring, but that’s not enough reason to keep it around. According to the Tennessee Exotic Pest Plant Council, the vine has crept in to open and dense canopied forest, forming mats and “extensive infestations” by vines that root at the nodes. They consider it a “significant threat” in the state, and note that it’s also considered invasive in several other southern states, and in California and the Pacific Northwest.
If your “infestation” is still fairly small, I suggest pulling it up, roots and all, if you can. You’ll probably have to pull it several times before it’s all gone. I never recommend chemical controls, but you can read what TNEPPC suggests here.
One of the nice features about the Tennessee Exotic Pest Plant Council’s web site is that they suggest alternatives for the invasive plants you might be considering for your landscape. So, instead of periwinkle, TNEPPC recommends using these natives:
Wild Blue Phlox (Phlox divaricata) and Creeping Phlox (Phlox stolonifera). Both attract bees and butterflies. Creeping phlox does best in the more acidic mountains of East Tennessee.
Several grass-like sedges make good groundcovers for shady places: Seersucker sedge (Carex plantaginea) has puckered light green leaves. Silver sedge (Carex platyphylla) has slightly puckered, light blue-green foliage. Blue wood sedge (Carex flaccosperma) has silvery blue foliage and can do well in wetter sites.
Partridgeberry (Mitchella repens) is a small creeping vine with tiny, glossy, deep green leaves, pairs of white fuzzy flowers in early June, and bright red berries. It grows in shade, and needs acid soil. Birds like it.
Golden Ragwort (Packera aurea [ Senecio aureus ]) has dark, evergreen foliage that colonizes as a groundcover and yellow flowers in early spring. Attracts bees and butterflies.
Marginal Woodfern (Dryopteris marginalis) is an evergreen fern that likes shade and moist soil.