How to Plant and Grow Evolvulus

A heat-loving plant, evolvulus thrives in the middle of a hot summer and continues to impress all the way through fall. One of the most remarkable characteristics of evolvulus is that its flowers come in one of the most elusive colors in the horticultural world: a bright, true blue.

With its showy blue blooms held against silvery-green foliage, this plant flourishes in a garden bed as a low-growing, drought-tolerant groundcover or in a container. A close relative of morning glory (yet not toxic), 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.

Where to Plant Evolvulus

Full sun is a must to get the most bloom out of your evolvulus. In terms of soil texture and acidity, the plant is quite adaptable, but excellent drainage is a must.

This is a low-growing, spreading plant that works well as a colorful seasonal filler in garden beds. It also looks great cascading down a wall or a raised bed. For the same reason, it is a popular choice for containers and hanging baskets. Plant it together with geraniums in a container for a simple but stunning blue-and-red combination.

How and When to Plant Evolvulus

Potted evolulus, commonly available as annuals at nurseries and garden centers, are planted in the spring after all danger of frost has passed. Dig a hole at least the size of the nursery pot or flat with the same depth. Water the plants well in their pots and let them drain before placing them in the hole and backfilling with the original soil. Space the plants 2 to 2.5 feet apart.

Evolvulus Care Tips

Light

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 so attractive.

Soil and Water

This tender perennial performs best in well-drained soil that is slightly acidic to slightly alkaline (pH between 6.0 and 7.2). Its drought-tolerant nature makes it a great option for neglected areas of the garden or even for containers that might receive infrequent water. It does not tolerate wet soil, which kills the plant.

Temperature and Humidity

Evolvulus needs warm weather. It flowers best in temperatures above 65 degrees Fahrenheit and thrives in the summer heat and tolerates humidity. As a tropical plant, it is highly sensitive to even light frost.

Fertilizer

Because evolvulus grows so rapidly, it needs monthly fertilization during the spring and summer. Apply a general-purpose liquid fertilizer according to the label directions.

Pruning

When the plant is young, prune it back a bit to encourage branching. Giving the growing tips a pinch every now and then can also help encourage a nice, bushy plant. As the summer progresses, 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 rebloom and make them look a bit tidier.

Evolvulus has the benefit of being self-cleaning, so deadheading is unnecessary.

Potting and Repotting Evolvulus

Select a 1-gallon pot with large drainage holes and fill it with a well-draining potting mix. Plastic or metal pots dry out less rapidly than terra-cotta and other porous materials. Still, the latter has the advantage of wicking away moisture, so there is less risk of root rot in the case of overwatering, which volvulus does not like. Remember, though, that potted volvulus does need more frequent watering and fertilization than inground plants.

Because it is usually grown as an annual and dies with the first frost, evolvulus does not require repotting.

Pests and Problems

The plant has no known serious insect or disease problems. 

How to Propagate Evolvulus

The common evolvulus varieties are all cultivars, and their seeds won’t produce plants that are true to their parents. Therefore, rooting stem cuttings is a more reliable method of propagating evolvulus.

In the summer, cut 3- to 5-inch tips from healthy stems. Strip off the leaves from the bottom third of the cutting, as well as any flowers and flower buds. Dip the cut end in rooting hormone powder. Fill a 4-inch container with a damp potting mix and insert the cutting about 2 inches deep. Place the pot indoors where the temperature is consistently around 65 degrees F and with bright indirect light but not direct sunlight. You can additionally cover the pot with a clear plastic bag, which prevents the soil from drying out fast and creates a humid environment for the cutting.

Water the plant moderately to keep the soil evenly moist but not soggy. After several weeks, you should see new growth, and the cutting should not wiggle when you gently tug on it. Continue growing the cutting in the pot indoors until the following spring, then plant it in the landscape or a larger pot after all danger of frost has passed.

Types of Evolvulus

'Blue Daze' Evolvulus

Evolvulus 'Blue Daze' offers bigger blue flowers than the common form and has slightly hairy gray-green foliage.

‘Blue My Mind' Evolvulus

This cultivar, with trailing silvery-green foliage, stands out by its extreme heat tolerance, making it the best choice for warm climates. It grows 12 inches tall and spreads up to 16 inches.

‘Hawaiian Blue Eyes’ Evolvulus

The flowers of this popular cultivar are slightly bell-shaped. New flowers appear daily throughout the growing season. The low-growing plant spreads 2 to 3 feet wide.

Evolvulus Companion Plants

French Marigold

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 to 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, returning year after year in spots where they're happy.

Nierembergia

The adorable cup-shaped 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 tie together taller and cascading plants visually. Though it's usually grown as an annual, nierembergia is perennial in Zones 7 to 10.

Tweedia

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 feet fall, tweedia will twine around short trellises or other supports. (Try a shrubby branch cutting inserted into the soil for naturalistic support.)