Grow and Care for Climbing Hempvine

Grow climbing hempvine in moist to wet ground, in sun or part shade, with a fence or thicket to twine on. Climbing hempvine is Mikania scandens, also sold as climbing hempweed — a native wetland vine, not hemp.

Keep it in moist to wet ground, in sun or part shade

Climbing hempvine is Mikania scandens, a twining perennial in the sunflower family. Give it sun or light shade and soil that stays moist to wet, the same stream bank, swamp edge, or wet thicket it uses in the wild. [1] Opposite heart-shaped to triangular leaves sit on long stalks. From summer into fall, flat-topped clusters of small white or pinkish flowers open from the leaf axils and draw bees and butterflies. [2] Stems typically run about 8 to 10 feet in a garden and scramble over a fence or low shrubs. Pair it with other moisture-loving plants, not with a dry mixed bed. A dry slope, a windowsill pot, or a bed that dries in August will not keep this vine going.

Plant it at a fence or in a wet thicket

Set a nursery plant after frost, in ground that already stays moist. Place the roots next to a fence, a trellis, or wet-edge shrubs it can twine around. It has no tendrils or aerial roots, so it needs something to wrap. Leave room for the scramble. Do not put it at a mailbox or in a small front-yard mix where it will smother neighbors.

1. Plant after frost, in moist to wet ground, not in a dry border.
2. Set the crown at the same soil line it had in the pot, next to a fence, trellis, or wet thicket.
3. Leave space for the vine to run. Do not plant it in a tight mixed bed or at a mailbox.
4. Water so the soil stays moist while the roots take, then keep that wet edge going.

Cut stems that smother other plants, and bag the pieces

When the site is wet and sunny, the vine covers what it can reach. Cut stems that bury small shrubs or swamp a neighbor. After frost the top dies back; cut the dead stems in late winter, or leave them until new growth starts. [3] Nodes root where stems lie on wet soil, and broken pieces can start new vines, so bag extras. Do not toss them into a ditch, a pond, or a storm drain.

1. Give it a fence, trellis, or thicket to twine on, so it is not hunting through a mixed bed.
2. During the growing season, cut stems that cover small plants you want to keep.
3. After frost, cut dead stems in late winter, or leave them until spring shoots show.
4. Bag the extras. Do not dump vine pieces in a ditch or pond, because nodes root on contact with wet soil.

Not hemp — and not mile-a-minute

The name climbing hempvine is a common name, not a cannabis crop. If you want hops, that is a different vine — see How to Grow Hops. Indian hemp is Apocynum, a dry-ground milkweed relative, not this wetland scramble — see How to Grow Indian Hemp. Triangular leaves can look like a morning glory at a glance, but morning glory leaves are usually alternate and the flowers are trumpets. If you have those blooms, read How to Grow Morning Glory.

Shops also call this plant climbing boneset because the flower clusters look like upright boneset. That is still this vine. White perfoliate boneset is Eupatorium, an upright wet-meadow plant — see How to Grow Joe-Pye Weed. A shop comparison to autumn clematis is a habit note, not the same plant. If you have fragrant white clematis in fall, read How to Grow Clematis. Mile-a-minute in Florida news is usually Mikania micrantha, a noxious weed with paler leaves, green leaf stalks, and white flowers. Climbing hempvine usually has medium-green leaves, reddish stalks, and pinkish flowers. [4] Barbed mile-a-minute is another plant again (Persicaria): alternate triangular leaves, hooked prickles, and saucer-shaped cups on the stem. This vine has opposite leaves and no barbs.

If the vine browns and never returns, the ground dried out or the crown sat in a pot. Keep the roots wet in sun or part shade, cut extra stems before they cover small shrubs, and bag the pieces.