Ipomoea quamoclit aka Hummingbird Vine

Ipomoea quamoclit has the common name cypress vine. It belongs to Convolvulaceae, the morning glory family. Kew gives its native range as Mexico through Central America. Other sources give a wider range within tropical America. It grows in the tropics where there is a dry season. This annual vine lives for one growing season. It climbs by winding around a support. Gardeners grow it for its red blooms and fine leaves.

Garden vines reach about 6–15 feet (1.8–4.6 metres) long. Some reach 20 feet (6.1 metres), as NC State also reports. Plants spread up to 6 feet (1.8 metres) wide. The thin green stems break with ease and need support. The green leaves split into fine parts like threads. This gives them a shape like a fern. Missouri Botanical Garden gives leaf lengths of two to four inches. NC State says the leaves draw in when in sun. They open again after sundown.

Small scarlet flowers grow in groups called cymes. Each bloom has a tube with five pointed lobes. Its open mouth gives it a star shape. Blooms measure about three-quarters of an inch across. Missouri Botanical Garden gives the bloom season as June through October. NC State says blooms last from early summer until fall frost. Hummingbirds and butterflies visit the blooms. Dry fruits called capsules form later. Their seeds are ready in fall. Each capsule stays under an inch long and wide. They split open and let their seeds fall out.

Grow cypress vine in full sun with soil that drains well. Plain garden soil suits it when moisture stays fairly even. It can take some drought but grows best with steady moisture. Sources say it can cope with brief wet or dry spells. Both gardening sources list USDA zones 11–12. Elsewhere, gardeners grow it as an annual in the warm months. Start seeds indoors six to eight weeks before the last frost. Sow seeds outside around the last spring frost. NC State advises scarifying seeds, which means wearing down their coats. Then soak them for 12–24 hours.

The vine can cover fences, trellises, arbors, and deck supports. Its fine leaves and red blooms suit gardens for pollinators. Both gardening sources report no major pest or disease problems. The plant also tolerates deer. It can drop seeds and return next year without planting. NC State calls it somewhat weedy, but not a native-plant threat. It is toxic to dogs, cats, horses, and people. Eating it can cause vomiting. Eating many seeds may cause hallucinations. NC State rates its human poisoning risk as low. The evidence supports growing it for looks, not for food.