Crossvine

Size, growth and what to expect

Crossvine grows fast, nearly three feet a year in our growth estimator. It climbs 30 to 50 feet into trees, and one plant spreads 6 to 10 feet wide. Its leaves stay on through mild winters and turn reddish purple, but a hard winter in zones 5 and 6 can strip them.

Trumpet flowers 2 inches long, reddish orange outside and yellow within, hang in clusters of two to five from March into May. The wild form's flowers carry a scent of mocha, which some named selections lack. Flat pods 4 to 7 inches long ripen in late summer, holding many winged seeds.

It grows wild from Maryland and the Ohio River valley south to Florida and west to eastern Texas. Its home is floodplain forests, swamps, hammocks and fence rows, where it climbs high into the trees. NatureServe ranks it critically imperiled in Oklahoma, at the edge of its range.

How to grow Crossvine

Crossvine flowers best in full sun and grows in part shade or even shade, with fewer flowers. It wants a moist soil rich in organic matter that drains well, yet it takes sand or clay, brief flooding and drought once established. Its branched tendrils end in sticky pads that let it climb brick, stone and fences without support. The pads can damage stucco, so against a house, set a trellis 5 feet from a wall and train it there. Set plants 12 feet apart. It burns readily, so where wildfire is a risk keep it out of the defensible space around a house. Keep it more than 50 feet from overhead wires.

Saplings ship bare-root or potted. Plant them in the dormant season, from late fall until bud swell, in a hole wider than the roots and no deeper. Set the crown at the soil line, put the native soil back in, and keep the mulch clear of the stems. Collect the pods from late summer into fall, once they turn light brown and begin to dry. The seed needs no treatment, so sow it in late winter or spring under an eighth of an inch of soil. Seedlings come up within three weeks, but survival can be low, and they may need a winter's chill before they grow on.

Water weekly through the first summer and in dry spells until it is established. Deer browse it in winter, so cage young plants where deer are many. Pull up root suckers as they appear, or it spreads well beyond its spot. Cut branches back in spring to bring on flowers, and thin crowded stems.

Each flower carries both male and female parts, so there are no male and female plants to pair. Hummingbirds are its main pollinators, and bees and butterflies visit too. It has no major pests.