Vinca—also known as Vinca minor, periwinkle flowers and creeping myrtle—is a popular ground cover that gets more popular every year. Established in-ground plants require little or no maintenance to thrive, but there are things you should know if you plan to put them in containers, indoors or out.
Indoors or Out?
Perennial varieties of vinca are hardy, evergreen crawlers that tolerate winter outside very well, but they can grow successfully in containers both outdoors and in. Vinca minor (common periwinkle) is a good choice, as it's a very hardy variety. Exercise caution when bringing vinca plants indoors, however, because the leaves are toxic if ingested. Keep plants away from children and pets.
First Things First
If bringing in an established outdoor plant for the winter, be sure to inspect it for disease. Common problems are canker, leaf spot, stem blight and root rot. Look for dark brown to black stems, lesions on the leaves and dark spots. Don't take it indoors if you see any of these signs.
If potting new plants (or dividing a root-bound one), plant in a good, general-purpose potting soil, one that can stay moist (not wet) and drain well. Having perlite in the mix will do the trick.
For a really happy plant, use warm water when watering, and mist occasionally with lime-free water. (Vincas are vulnerable to blight in cold and soggy soil.) Feeding season is spring to fall when plants should be fed every two weeks. Do not feed during the winter.
While indoors, keep the plant in a sunny room with the temperature between 50 and 75 degrees and they could bloom all winter; but it will not do well unless it has a good source of natural light. The best is full sun from the south/west.
They Grow Up So Fast!
Vinca can be propagated easily from cuttings. Use a mix of half perlite, half moist peat moss. Roots grow from the nodes, so make sure a node is under the surface of the soil. Create a greenhouse effect by putting a plastic bag over the plant and securing it with a rubber band around the rim of the pot. It can be transplanted into potting mix when roots have sprouted and you can see some new growth.
Although in-ground vinca can survive almost anything, eventually, potted vinca is likely to succumb to some kind of disease because that balance between moist soil and good drainage, essential to potted plants, is always tricky. You can divide the roots and plant it outside in part sun and part shade and it will last forever. In fact, it can grow out of control outdoors if you don't keep it in check.