Ipomoea tricolor aka Heavenly Blue Morning Glory

Ipomoea tricolor is a morning glory from Mexico. It belongs to the bindweed family, Convolvulaceae. It grows in scrub, thickets, hedges, and disturbed ground. People grow it as an ornamental in many countries. It has also spread beyond gardens in tropical regions. Sources differ on its life cycle. Some describe an annual; others describe a short-lived perennial. Gardeners in cool climates grow it as an annual climber.

The vine grows fast and climbs by twining around supports. Garden height ranges from 8–13 feet [2.4–4 metres]. One tropical account describes stems reaching 16 feet [5 metres]. Spread ranges from about 1.6–6 feet [0.5–1.8 metres] across garden sources. The green stems are soft and smooth. Its green, heart-shaped leaves have fine hairs and smooth edges. Each leaf is simple, and leaves alternate along the stems. The plant loses its leaves rather than staying evergreen.

Flowers bloom from midsummer into fall. Their fused petals form a funnel or trumpet. Flowers may be blue, purple, pink, or white. Pale throats and star-like white marks add contrast. Each flower opens in the morning and fades that day. Flowers measure about 0.08–0.25 feet [0.025–0.076 metres] across. Butterflies and hummingbirds visit the blooms. The fruit forms a dry capsule that splits when ripe. It holds small black seeds, which can sow themselves.

Grow this vine in full sun, sheltered from cold winds. It needs moist soil that drains well, without standing water. RHS lists acid, neutral, and alkaline soils as suitable. It can grow in poor soil with little fertilizer. It also tolerates heat and city conditions. RHS rates it H1C for summer outdoor growing in Britain. It does not tolerate frost well. Trellises, arbors, fences, and walls provide support for climbing stems. It also suits containers, hanging baskets, and use as ground cover. RHS says it needs no pruning.

Self-sown plants can become weeds and cause problems on farmland. Some parts of the United States class it as noxious. Serious pest and disease problems are uncommon. Aphids, spider mites, leaf miners, and caterpillars may still attack. No edible uses are reported. The plant is harmful to people, dogs, cats, and horses. Seeds can cause hallucinations, nausea, vomiting, diarrhea, and drowsiness. Eating leaves or stems may also cause vomiting. Sources report past medicinal use of the seeds. That history does not establish safe use. Both RHS and NC State advise protective gloves when handling it.