3 Mild-Mannered Morning Glory Flowers That Won’t Reseed

When you say you’re growing morning glories, the first thing you hear from other gardeners is “You’ll be sorry!” – and for good reason. Common morning glories (Ipomoea purpurea) can shed so many seeds that they become persistent weeds, particularly in warm climates. But this is simply not true of several closely related species, including Japanese morning glories, bold red cardinal climber, and the elusive Heavenly Blues.

The three non-invasive morning glories profiled here can grow into impressive vines in the course of a season, but they are weak reseeders that won’t be back unless you plant them again.

Japanese Morning Glories

For at least 900 years, Chinese and Japanese gardeners have grown and selected special strains of Ipomoea nil, which blooms in a huge range of colours, often with petals edged with white. This species has three-lobed leaves compared to the heart-shaped leaves of common morning glory. And while the plants can reseed under favourable conditions, Japanese morning glories produce only a few seeds, which usually succumb to winter.

Japanese breeders were big into mutations in the mid 1800s, which opened the door to morning glories with variegated leaves and varying growth habits. Today’s Japanese morning glories are beautiful and fast to bloom, often setting buds 8 to 10 weeks after planting from seed.

Japanese morning glory varieties that produce very large flowers such as Chocolate produce only a few showy blossoms, while smaller-flowered varieties like Early Call Blue and Scarlett O'Hara are more vigorous growers that can cover a trellis with blossoms. If you just want to have fun, try the growing the plants in containers where they can be viewed up close.

Carefree Cardinal Climbers

Commonly known as Ipomoea x multifida, cardinal climber has recently been renamed Ipomoea x sloteri, in honor of its breeder. From 1897 to 1908, Logan Sloter of Columbus, Ohio, tried and tried to hybridise two morning glory species, and finally got a few viable seeds of this unique plant with deeply cut leaves and bright red flowers.

Easy to grow in beds or containers, cardinal climber blooms from midsummer to frost. The unusual leaves make cardinal climber a real eye-catcher, and hummingbirds and bees love the little flowers. This non-invasive morning glory produces only a few seeds, which do not survive winter and must be collected and saved for replanting.

Late-Blooming Blue Morning Glories

Originating in Mexico and Central America, many Ipomoea species are short-day plants that wait until nights become long in early autumn to bloom. This is true of Heavenly Blue, striped Flying Saucer, Blue Star, and other selections of Ipomoea tricolor. The vigorous vines will grow like crazy all summer, but wait until days are less than 12 hours long to bloom.

Patience has its rewards, because a pillar or fence covered with pristine pastel morning glories with yellow throats in September can be a wonderful thing. Late blooming also reduces the plants’ seed production potential, with few seeds ripening before the plants fail due to cold and old age.

Morning Glory Growing Tips

Morning glories are fast and easy to grow from seed in spring, on the same schedule as tomatoes. They require warm weather for vigorous growth, and are often quite successful in containers.

A day before planting, nick the seeds with a nail clipper to create a shallow cut in the seed coat. Then soak the seeds in room temperature water overnight before sowing in a clean seed starting mix. Give the seedlings strong light, and pinch the primary growing tips to induce branching when the seedlings have six true leaves.

Get creative with trellising, because twining morning glories will grow on anything, from woven string to a sturdy fence. Provide plenty of water in hot weather, but don’t feed plants unless they show pale, spindly growth. Blooming of morning glories can be delayed and reduced by excessive nutrients.