Yellow morning glories offer a bright, cheerful display in gardens. These vining plants are recognized for their beautiful trumpet-shaped blossoms and heart-shaped leaves. Their rapid growth and abundant flowering contribute to their widespread appeal.
Understanding Yellow Morning Glories
Yellow morning glories feature distinctive trumpet-shaped flowers, often with a dark center, and grow along fast-climbing vines. While “morning glory” encompasses many colors, specific yellow varieties provide a unique golden hue. Notable yellow species include Ipomoea hederifolia lutea (Yellow Trumpet Morning Glory), which produces butter-yellow trumpets that can stay open longer than typical morning glories. Another is Distimake aureus (Yellow Morning-Glory or Yellow Woodrose), a woody vine with large, bright yellow, trumpet-shaped flowers that bloom year-round in suitable climates. Ipomoea obscura (Yellow Obscure Morning Glory) displays cream or pale yellow petals with a darker, often purple, center and radiating yellow lines.
Cultivating Yellow Morning Glories
Yellow morning glories thrive in full sun, ideally at least six hours daily, to encourage abundant blooming. They prefer well-draining, moderately fertile soil; overly rich soil with too much nitrogen can lead to more foliage and fewer flowers. While establishing, regular watering is important, but once mature, they tolerate drier conditions, requiring water once or twice a week during dry spells.
These vigorous vines require support structures like trellises, fences, or pergolas to climb, as they can reach heights of 10 to 12 feet or more in a single growing season. Propagation is primarily from seed, which benefits from scarification (nicking the hard outer coat) and soaking in warm water overnight to improve germination rates. Seeds can be sown 1/4 to 1/2 inch deep, either indoors 4-6 weeks before the last frost or directly outdoors once the soil temperature is consistently warm. When seedlings are a few inches tall, they can be spaced 6 to 12 inches apart, though care should be taken when transplanting due to their sensitive roots.
Morning glory flowers typically open in the morning and close by afternoon, though some varieties, like Ipomoea hederifolia lutea, may stay open longer on overcast days. These vibrant blooms attract pollinators such as bees, butterflies, and hummingbirds. During the growing season, a balanced liquid fertilizer can be applied monthly, but avoid over-fertilizing to prevent excessive foliage growth at the expense of flowers.
Important Considerations
To manage growth and encourage continuous flowering, pruning and deadheading are beneficial. Removing spent flowers before they form seed pods helps prevent prolific self-seeding, which can lead to unwanted volunteer seedlings. This practice helps control their spread.
Morning glories can encounter pests and diseases. Common pests include aphids and spider mites, which can cause yellowing leaves and stunted growth. Fungal diseases like powdery mildew, root rot, and rust can also affect morning glories, often indicated by yellowing leaves or powdery lesions. Ensuring good air circulation and avoiding overhead watering helps prevent fungal issues.
A significant consideration for morning glories is their potential for toxicity. Morning glory seeds contain a chemical that can cause nausea, vomiting, and hallucinogenic effects if ingested, so keep seeds away from children and pets. While the flowers are not considered dangerous, caution is advised.
It is important to distinguish cultivated morning glories (Ipomoea species) from Field Bindweed (Convolvulus arvensis) and Hedge Bindweed (Calystegia sepium), often mistakenly called “morning glory” due to similar trumpet-shaped flowers. Field Bindweed, a highly invasive perennial weed, spreads aggressively via deep rhizomes that can extend over 10 feet in a single season, and its seeds can remain dormant for decades. True morning glories, typically grown from seed, have distinct heart-shaped leaves, whereas bindweed leaves are often arrow-shaped or more pointed. Unlike bindweed, which forms extensive root systems and is difficult to eradicate, many cultivated morning glories are annuals in cooler climates, dying back after the first frost, and their spread can be managed by controlling seed dispersal.