A lover of heat, evolvulus thrives in the middle of a hot summer and continues to impress all the way through fall. With its showy blue blooms held against silvery-green foliage, this plant flourishes in a garden bed as a low-growing groundcover or in a container. A close relative of morning glory, the flowers tend to have a few of the same quirks, including closing up at the end of the day and re-opening the following morning.
One of the most remarkable characteristics about evolvulus is that its flowers come in one of the most elusive colors in the horticultural world: a bright, true blue. Blooming from late spring all the way until frost, evolvulus has the benefit of being self-cleaning, so there is no need to worry about removing old spent blooms.
Evolvulus Care Must-Knows
This tender perennial performs best in well-drained soil, whether in the ground or in a container. Its drought-tolerant nature makes it a great option for neglected areas of the garden or even for containers that might receive infrequent water. One of the quickest ways to kill evolvulus is to get it too wet.
To get the most color out of your evolvulus, be sure to plant it in full sun to encourage continuous flowering throughout the season. Sun also helps maintain a compact shape and pretty silver-colored foliage. If planted in too much shade, evolvulus will often take on a sprawling appearance, bloom less frequently, and lose some of the silvery sheen that makes its foliage look so nice.
When first starting evolvulus, prune the plant back a bit to encourage branching. Giving the young growing tips a pinch every now and then can also help to encourage a nice, bushy plant. As the seasons draw on, evolvulus may begin to look a bit tired and leggy, and blooming may slow down. At this point, cut back the plant to help encourage a fresh new flush of growth. This will also help plants to rebloom and make them look a bit tidier.
More Varieties of Evolvulus
Evolvulus Companion Plants
Just as you'd expect from something called French, these marigolds are the fancy ones. French marigolds tend to be frilly and some boast a distinctive "crested eye." They grow roughly 8-12 inches high with a chic, neat, little growth habit and elegant dark green foliage. They do best in full sun with moist, well-drained soil and will flower all summer long. They may reseed, coming back year after year, in spots where they're happy.
The adorable cup-shape flowers of nierembergia and its neat growth habit make it a useful annual flower for everything from containers to edging. Plant it in rows along the front of beds or borders for a crisp look (especially with the white types). Or use it in containers—it's a great medium-height plant to visually tie together taller plants and cascading plants. Though it's usually grown as an annual, nierembergia is perennial in Zones 7-10.
If you love blue flowers, tweedia is for you. Tweedia produces beautiful turquoise blooms all season on grayish, felted foliage. The fragrant five-petal flowers make great cut flowers, complimenting any bouquet. A short vine growing 2 to 3 fall, tweedia will twine around short trellises or other supports. (Try a shrubby branch cutting, inserted into the soil for a naturalistic support.)