The Morning Glory Tree (Ipomoea arborescens) is unique for its tree-like growth habit, unlike its more common vining relatives. Native to the dry desert tropics of Northwestern Mexico, this species offers striking trumpet-shaped flowers. Its aesthetic appeal makes it a favored ornamental plant, especially in warmer climates where it thrives.
Morning Glory Tree Characteristics
The Morning Glory Tree grows as a tropical, deciduous tree, reaching 16 to 40 feet tall with an 11 to 24-foot spread. It has a stout trunk, branches with pale, yellowish bark, and large, round or heart-shaped green leaves. It is deciduous, shedding leaves in late summer, and flowers in winter and early spring before new foliage appears. Its showy, trumpet-shaped flowers are typically white, sometimes with a greenish throat or purple spots, measuring around 6 cm in diameter.
Growing and Caring for Morning Glory Trees
Successful cultivation of the Morning Glory Tree requires specific environmental conditions and ongoing care. Proper light, soil, water, temperature, pruning, and fertilization ensure a healthy specimen.
Light Requirements
The Morning Glory Tree thrives in full sun, requiring at least six hours of direct sunlight daily for optimal growth and flowering. While it tolerates partial sun, insufficient light can lead to slow growth and leaf loss.
Soil Preferences
This tree performs best in well-drained soil and tolerates various pH levels, including neutral, slightly alkaline, or slightly acidic. Good drainage is important to prevent water accumulation, which can negatively impact the root system.
Watering Needs
The Morning Glory Tree prefers moist soil but is adapted to dry conditions. Water when the soil surface appears dry, ensuring the soil fully absorbs the water. During hot summer months, watering 1-2 times daily may be necessary due to high evaporation, ideally in cool mornings and late afternoons.
Temperature and Humidity
This species thrives in warm, humid climates, with ideal temperatures ranging from 68 to 95°F (20 to 35°C). It tolerates high temperatures but is susceptible to cold and frost, making it best suited for USDA hardiness zones 9 and above. Temperatures below 50°F (10°C) can slow or stop growth, and frost damage can be fatal.
Pruning
Pruning the Morning Glory Tree maintains its shape, promotes healthy growth, and encourages abundant blooms. The best time for pruning is late winter or early spring before new growth begins. Focus on removing dead or damaged branches, thinning overcrowded areas to improve air circulation, and shaping the tree.
Fertilizing
The Morning Glory Tree needs fertilizer to support vigorous growth and flowering. During the seedling stage, a small amount of organic fertilizer promotes initial development. Consistent fertilization is recommended throughout the spring and summer growing seasons. For potted plants, add nitrogen fertilizer when repotting and apply foliar fertilizer monthly. Phosphate and potassium fertilizer applied once or twice during the early flowering period can stimulate more blooms.
Propagating Morning Glory Trees
Morning Glory Trees can be propagated through seeds or cuttings, each method having specific requirements for success.
Seeds
For seed propagation, soak seeds in water for 6-12 hours to aid germination. Sprinkle them on the soil surface and cover with a thin layer of soil, or plant in small holes about 2-3 cm deep. Keep the soil consistently moist; germination typically occurs within about a week.
Cuttings
For cuttings, select healthy, semi-hardwood stems from a mature plant. Cut a 10 cm section diagonally, removing 2-3 lower leaves. Soak cuttings in water until roots develop, then plant in moist soil. Place planted cuttings in a semi-shaded, well-ventilated location for successful establishment.
Air Layering
Air layering is another effective method, particularly for woody plants. Wound a branch, apply rooting hormone (optional), and wrap the wounded area with moist sphagnum moss covered in plastic to create a humid environment. Once roots form, separate the new plant from the parent tree and transplant it.
Morning Glory Tree vs. Vining Morning Glories
The Morning Glory Tree (Ipomoea arborescens) is often confused with common vining morning glories (Ipomoea purpurea or Ipomoea tricolor), but they have distinct characteristics. The most significant difference is growth habit: Ipomoea arborescens develops into a woody tree, while its vining counterparts are herbaceous climbers. The tree can reach 16 to 40 feet with a stout trunk, whereas vining morning glories typically grow as fast-climbing vines, reaching up to 10-15 feet in a single growing season.
Their lifespan is another key distinction; the Morning Glory Tree is a perennial that can live for many years, whereas most vining morning glories are annuals in temperate climates. Even in warmer zones where vining varieties act as perennials, they typically die back each winter. While both share trumpet-shaped flowers, the tree’s blooms often appear when it is leafless in winter, a different blooming period than the summer-to-fall display of vining types.
Benefits and Important Considerations
The Morning Glory Tree enhances landscapes with its ornamental value. Its striking trumpet-shaped flowers contribute to garden aesthetics, particularly during its winter blooming period when many other plants are dormant. These flowers also serve as a food source for various pollinators, including hummingbirds, bees, and long-nosed bats, contributing to local biodiversity. The tree’s substantial size can provide shade, making it a functional addition to larger outdoor spaces.
When planting a Morning Glory Tree, note that Ipomoea family seeds, including Ipomoea arborescens, contain alkaloids that can be toxic if ingested in large quantities. Keep seeds away from pets and small children. While generally not invasive, rapid growth and self-seeding can occur in suitable climates, so monitoring its spread is prudent. The tree’s susceptibility to frost means it is best suited for warmer climates (USDA Zone 9 and above) where it can thrive without winter protection.