Morning Glories and More

‘Crimson Rambler’

If you’re in search of a fast return on your springtime ornamental investment, pop in a selection from the genus Ipomoea, whose best-known members are morning glories, those old-fashioned, easy-to-grow flowers you probably planted in kindergarten. A look beyond these delights of the dawn yields other equally amenable plants: swirling night-bloomers, petite blossoms that remain open all day, and ornamental varieties of a tasty root vegetable. These are just a few of the gems offered by this genus.

Dawn bloomers offer a riot of color

‘President Tyler’ Photo/Illustration: Todd Meier

Any tour of the morning glory kingdom must begin with the dawn-bloomers themselves—the prolific, insouciant vines of Ipomoea tricolor, I. purpurea, and I. nil. All three are tropical natives that have naturalized widely in the United States. Aptly named, morning glories open their vibrant flowers at sunrise and typically close them by lunchtime, though an extremely cool or cloudy day can postpone the inevitable until late afternoon.

Able to scale a post of 10 feet or taller, morning glories bear handsome heart-shaped leaves and 2-to-6-inch, flat-faced, funneled flowers that unfurl from tightly wrapped buds. These age-old climbers hold the magic of Jack’s beanstalk within each small seed. They sprout in days and grow fast enough that you can almost hear the vines’ whispered race (“First to the top of the post—yes!”). They also contribute voluptuous blossoms, one after another, to the cool morning hours of summer, then pass swiftly into oblivion as the sun slants toward autumn.

‘Grandpa Otts’

Many “blue” flowers are really some shade of purple—ask any child with a decent set of crayons—but the 4-inch-wide plates of heirloom Ipomoea tricolor ‘Heavenly Blue’ are satiny versions of the sky itself (despite photographs which often render it otherwise). I. tricolor ‘Pearly Gates’, introduced in 1942, is to white clouds what ‘Heavenly Blue’ is to the sky, while I. nil ‘Scarlett O’Hara’, described in catalogs as red, is really a luscious shade of deep rose-crimson. I. t. ‘Crimson Rambler’ is similar in petal color, but it softens to white at the throat.

I. nil ‘Tie Dye’ would look good on a Grateful Dead T-shirt, with its 6-inch-wide grape-juice-purple blooms streaked with white and lavender. So would I. tricolor ‘Flying Saucers’, a batik-looking blend of white and blue accented by a golden throat. I. p. ‘Milky Way’ combines creamy white blossoms with five purple brush strokes that create a starry accent. I. p. ‘Star of Yelta’ produces rich purple blossoms that pale toward the center to lavender. Its five raised ribs form a red-violet star. I. purpurea ‘Grandpa Otts’ is a close match to ‘Star of Yelta’, but this heirloom variety has vigor enough to climb up to 15 feet. Far-northern gardeners may be happiest with I. purpurea ‘President Tyler’, another heirloom, which flowers in just 45 days from sowing. Its royal-purple flowers bear a maroon star and a handsome throat that shades from deep magenta to white. Can’t decide which color suits your garden? A rainbow can be had with I. nil ‘Early Call Mix’, a compact seed strain growing 5 to 6 feet tall.

More intriguing but harder to grow well are the variegated-leaf cultivars of Ipomoea nil, the imperial Japanese morning glory, often incorrectly listed as I. imperialis. Grown in Japan since the 6th century, morning glories are known in that country as asagao, or morning faces. My favorite I. nil cultivar is ‘Chocolate’, which bears 6-inch-wide flowers whose color could best be described as medium rose with a dash of cocoa added. ‘Rose Silk’ is a similar shade, but with a white-picoteed edge that sets off the antique rose beauti­fully. In both selections, white-splashed leaves complement the flowers. The Japanese morning glory selections are happiest in my humid garden in dry summers and are prone to leaf diseases in rainy years. Able to climb an arbor or trellis, cover chain link, or shinny up the stem of a giant sunflower, morning glories can be planted anywhere that fast summer coverage is desired. They can also be grown like pea vines on temporary trellises made from untreated jute twine. At season’s end, cut vine and twine down together and carry them to the compost pile. During the growing season, be careful not to let your morning glories’ rapid growth and entwining ways overwhelm less vigorous plants. A morning glory trained into a small conifer or young tree could disfigure or kill its host.

‘Flying Saucers’ Photo/Illustration: Courtesy of Burpee Seed Co.

‘Milky Way’ Photo/Illustration: Courtesy of Burpee Seed Co.

Ipomoea alba Photo/Illustration: Todd Meier, inset Robert E. Lyons

‘Tie Dye’

‘Chocolate’

‘Rose Silk’ Photo/Illustration: Virginia Small

Moonflowers are a treat to the eyes and the nose

Ipomoea X multifida Photo/Illustration: Lee Ann White

Much as I love morning glories, others now vie for my attention and planting space. Who could be without moonflower, Ipomoea alba, a plant for which night gardens are made? During the day, its elongated, swirled buds resemble exotic candy sticks. At dusk they open into pure-white, tissue-fine flowers. Night-flying hawkmoths find the sweet nectar of each outfacing 6-inch-wide saucer irresistible, while I love the delicate powdery scent that emanates from the blossoms. Line a path with these and let the moonlight reflected in their softly shining beacons light your way. 

Cypress vine, Ipomoea quamoclit, earns its place in the garden with deeply cut, feather-fine leaves and rich red inch-wide blossoms. The starry flowers are beautifully set off by the gossamer foliage, and best of all, they stay open all day long. Harder to find are the white and reddish-pink forms of cypress vine, though sometimes the seeds are available as a mix. Cypress vine grows so quickly that I was initially surprised at its vigor. Who would expect a 15-to-25-foot vine from so dainty-looking a plant?

Cardinal climber, Ipomoea X multifida, is a hybrid of cypress vine and the scarlet morning glory, I. coccinea. The leaves of cardinal climber are less finely cut than cypress vine leaves. Like paper fans or silhouettes of birds in flight, they look jazzier than their cousin’s fine fronds. Cardinal climber bears rounded inch-wide flowers painted the hot scarlet of cardinals or holly berries. It’s at its best with equally fiery plant companions. Both cardinal climber and cypress vine have been long-season performers in my garden, flowering freely and retaining healthy foliage until frost. Hummingbirds feast gratefully on either selection.

Ipomoea quamoclit Photo/Illustration: David Cavagnaro

Ipomoea coccinea Photo/Illustration: Robert E. Lyons

Currently there are several delightful ornamental sweet potato vines available, with new selections destined for release. The luscious leaves of Ipomoea batatas ‘Pink Frost’ (also sold as ‘Tricolor’) are a candied confection of baby pink, soft green, and creamy white. ‘Margarita’ (also sold as ‘Marguerite’) bears bright chartreuse hearts that never scorch in intense sun. Surprisingly for such a sun worshipper, ‘Margarita’ even holds its color well in light shade, as does ‘Pink Frost’. A fine line of red-violet edging on the chartreuse leaves of ‘Margarita’ makes a terrific color echo with Verbena ‘Homestead Purple’.

‘Sweet Caroline Bronze’

Photo/Illustration: Robert E. Lyons

‘Pink Frost’ Photo/Illustration: Robert E. Lyons

Two cultivars sport rich purple-black foliage: the leaves of ‘Blackie’ are deeply cleft while ‘Ace of Spades’ produces perfectly formed hearts. ‘Ladyfingers’ (NCSU #99) came from North Carolina State University. Its three-pointed olive-green leaves bear deep-purple veins. Look for the new ‘Sweet Caroline’ series from NCSU as well. ‘Sweet Caroline Bronze’, with its reddish-bronze overlay, brings a new color to the sweet potato vine lineup.

To prevent the spread of destructive sweet potato weevils, ornamental sweet potato vines are prohibited from sale (or about to be) in regions where edible sweet potatoes are grown as a commercial crop. Don’t share cuttings with gardeners who live where sweet potatoes are grown, and by all means do not plant them if you live in sweet potato country yourself. Remember—the dinner you save could be your own.

‘Margarita’

‘Blackie’

Provide them all with a place in the sun

Members of the Ipomoea genus are sun lovers that perform best with adequate water and moisture-retentive mulch. Overly rich soil favors vine growth over flowering, so moderately rich soils are preferred. Though I’ve seen morning glories growing well in heavy clay, sweet potato vines do best with well-drained soil to prevent tuber rot. Powdery mildew can afflict the leaves of common morning glories in late summer, especially in dry years, but I have never found the disease to be a problem on other selections. Deer, those soft-eyed thieves of a gardener’s hard labor, especially love Japanese morning glory, moonflower, and sweet potato vines. Surprisingly, they have never troubled my cypress vine or cardinal flower. Despite these potential problems, few plants are more cheering to grow, giving satisfaction day after day, just as they may have done in your grandmother’s garden.