Tall Morning-Glory: A Fast-Growing Annual Vine for Quick Garden Impact
If you’re looking for a vine that can transform a bare fence or trellis into a colorful backdrop in just one growing season, tall morning-glory might catch your eye. This enthusiastic climber has been charming gardeners for generations with its heart-shaped leaves and trumpet-shaped blooms that greet the morning sun.
What Is Tall Morning-Glory?
Tall morning-glory (Ipomoea purpurea) is an annual climbing vine that belongs to the morning-glory family. You might also see it listed under its scientific synonyms like Convolvulus purpureus or Pharbitis purpurea in older gardening references. As an herbaceous annual, it completes its entire life cycle in one growing season, producing seeds before the first frost kills the plant.
Where Does It Come From?
While tall morning-glory has naturalized across most of North America, it’s actually not native to our continent. This vine originally hails from tropical America, including parts of Mexico, Central America, and South America. Today, you’ll find it growing wild in all 50 US states, most Canadian provinces, and Puerto Rico, where it has established itself as a non-native species that reproduces readily without human intervention.
Garden Appeal and Characteristics
What makes tall morning-glory so appealing to gardeners is its rapid growth and reliable blooms. The vine can easily reach 6-10 feet in a single season, quickly covering structures with its attractive foliage. The flowers, which typically measure 2-3 inches across, come in shades of purple, pink, white, and blue. True to their name, these blooms open in the early morning hours and usually close by mid-afternoon, especially on hot days.
The heart-shaped leaves create a lush backdrop for the colorful flowers, and the vine’s twining habit makes it excellent for covering fences, arbors, mailboxes, or any vertical structure that needs softening.
Growing Conditions and Care
One of tall morning-glory’s biggest selling points is how easy it is to grow. This vine thrives in full sun and well-drained soil but isn’t particularly fussy about soil quality. In fact, it often performs better in average to poor soils than in overly rich conditions, which can lead to more foliage than flowers.
The plant prefers upland conditions and rarely tolerates wet feet – it’s classified as obligate upland in most regions, meaning it almost never occurs in wetland areas. In the Great Plains, Midwest, and Northcentral regions, it shows slightly more tolerance for occasional moisture as a facultative upland species.
Planting and Propagation
Since tall morning-glory is an annual, you’ll need to start fresh each year from seed. The good news is that the seeds are large and easy to handle. For best results:
- Soak seeds overnight before planting to improve germination
- Direct seed in the garden after the last frost date
- Plant seeds ¼ to ½ inch deep
- Provide a support structure from the start – the vine begins climbing almost immediately
- Space plants 6-12 inches apart
In warmer climates (USDA zones 9-11), tall morning-glory may self-seed, giving you volunteers the following year.
Wildlife and Pollinator Value
While tall morning-glory does provide some wildlife benefits, they’re relatively modest. The flowers attract bees, butterflies, and occasionally hummingbirds with their nectar. However, research indicates that it provides only a small percentage (2-5%) of the diet for both large animals and terrestrial birds, and offers sparse cover value.
Should You Plant It?
Tall morning-glory can be a great choice for gardeners who need quick, temporary coverage or want to add vertical color to their landscape. It’s particularly well-suited for:
- Cottage-style gardens
- Annual flower displays
- Screening unsightly areas temporarily
- Children’s gardens (large, easy-to-handle seeds)
However, since it’s not native to North America, consider pairing it with or substituting native alternatives like American groundnut (Apios americana), wild bean (Strophostyles helvola), or native honeysuckles (Lonicera species) for better ecological value.
Potential Drawbacks
While not officially classified as invasive, tall morning-glory can self-seed aggressively in favorable conditions. Some gardeners find volunteer seedlings popping up in unexpected places the following year. If this concerns you, deadhead spent flowers before they set seed, or choose native alternatives that support local ecosystems more effectively.
The vine can also become quite vigorous and may overwhelm smaller plants or structures if not managed properly.
The Bottom Line
Tall morning-glory offers quick gratification for gardeners who want fast-growing color and coverage. While it may not be the most ecologically beneficial choice, it’s not harmful either. If you decide to grow it, enjoy its cheerful morning blooms while also considering native vines that could provide similar beauty with greater wildlife value. After all, the best garden is one that brings you joy while supporting the local ecosystem whenever possible.
