Morning glory

About Morning glory

Morning glories are fast annual vines from Mexico and Central America with heart-shaped leaves and trumpet flowers that open in the morning and fade by afternoon. One plant can cover a fence or trellis in a single summer, and hummingbirds and butterflies visit the flowers (NC State, Iowa State). They drop lots of long-lived seed, and common morning glory is also a farm weed (the app's tall morning glory weed page); Arizona lists both species as prohibited noxious weed seeds, and the seeds are poisonous.

Grown as a summer annual in every zone (NC State); Arizona's seed rules prohibit selling seed of common morning glory and I. tricolor, and some other states limit morning glory seed in farm seed.

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

• Start seeds indoors: 4 to 6 weeks before the last frost
• Set out plants: up to 2 weeks after the last frost
• Sow seeds outdoors: up to 2 weeks after the last frost

Nick the hard seed coat with a file or soak seeds overnight in warm water, then sow outdoors after frost danger has passed or start indoors 4-6 weeks before setting out (Iowa State, NC State, Illinois). There is no sourced count from sowing to bloom; Cornell weed scientists note common morning glory flowers about 6-8 weeks after the seedlings come up. Give vines a trellis, fence or strings to twine on.

Soil

Average, well-drained soil; it blooms well in poor soil with little or no fertilizer and doesn't like standing water (NC State, Illinois).

No compost or fertilizer needed; average or even poor, well-drained soil suits it (NC State, Illinois).

Feeding

Skip rich soil and extra fertilizer: Illinois Extension says morning glories prefer low fertility, and NC State notes they bloom well with little or no fertilizer.

Harvest

Blooms from early or midsummer until frost; each flower lasts only a morning, staying open longer on cloudy days (NC State, Iowa State). There's no need to deadhead for more flowers, but pulling off seed pods before they dry and split cuts down on next year's volunteers.

Varieties (12)

Extension sources document 12 named morning glories, several with no traits listed. NC State's species assignments are followed as given.

Pests to watch for

Aphids, Twospotted spider mite, Leafminers

Diseases and problems

Powdery mildew, Root rot

In the kitchen

Safety: The seeds are poisonous: eating them can cause nausea, vomiting, diarrhea, dilated pupils and, in larger amounts, hallucinations (NC State: low severity). Leaves and stems may cause vomiting. Keep seeds away from children and wear gloves when handling plants.

Pets: Toxic to dogs, cats and horses (ASPCA, Ipomoea spp.): indole alkaloids related to lysergic acid cause vomiting, and eating large amounts of seeds may cause hallucinations.