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Japanese Hops

Humulus scandens (HUM-uh-lus SKAN-denz)

Family: Cannabaceae Non-native Vine (vertical)

Japanese Hops is an annual with a tap root, a climbing or twining vine in the hemp family. It is native to eastern Asia, from Russia to North Vietnam. The plant is often found escaped from cultivation along rivers and stream, abandoned home sites, and other moist, disturbed habitats. The plant's stems are twining with branched stalk hairs that aid it in climbing. These stems can reach up to 35 feet and allow the plant to climb structures or to spread along the ground. The leaves are opposite, mostly 5-lobed with a rough texture. Flowers are greenish, appearing in mid-summer to fall. There are separate male and female vines. Both produce small, five-petaled flowers. Male flowers occur in airy clusters, while female flowers are in short spikes. Fruits appear in elongated clusters, enclosed in a papery sac-like bract. Japanese Hops is a larval food source for several species of butterflies. The genus name comes from a Latinized Medieval name of the hop plant. The species epithet, scandens , means "climbing." Although it can grow in just about any soil type, its most vigorous growth will be in moist fertile loam. Although an annual, Japanese Hops can survive mild winters. This drought-tolerant plant is listed as invasive in several of the United States and has escaped cultivation in many areas where it may displace desirable species. In the United States, most infestations are in eastern states, but the species is spreading in the Midwest. Seeds are spread by wind and water, allowing the plant to reseed itself and often forms dense colonies of overlapping vines. For this reason, planting Japanese Hop is not recommended. Japanese Hops can easily be distinguished from the better behaved American Hops; Japanese Hops have leaves with 5–7 lobes, American Hops have leaves with 3 lobes or none. This plant serves as a host plant for the Gray hairstreak ( Satyrium sylvinus ) , Eastern comma ( polygonia comma ) , Question mark ( plygonia interrogationis ) , and Red Admiral ( Vanessa atalanta ) butterflies. Diseases, Insect Pests, and Other Plant Problems: The plant is invasive in some states. Control can be maintained by pulling plants before its seeds set, ensuring to remove as much of the root system as possible. No known diseases or insect problems.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 70 attributes.

How it fits the guild

Guild layer 6 - Vine (vertical) Optimal soil pH Alkaline (>8.0); Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Often confused with Humulus lupulus

Full plant profile

Growing Conditions
Plant type
Annual; Vine
Life cycle
Annual
USDA zones
4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; Loam (Silt); Sand
Soil pH
Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Occasionally Dry | Occasionally Wet
Available space
12 inches-3 feet
NC region
Coastal; Piedmont
Growth rate
Rapid
Maintenance
High
Canopy layer
6 - Vine (vertical)
Form & Appearance
Habit / form
Ascending; Creeping; Spreading
Texture
Medium
Foliage
Deciduous
Leaf color
Green
Leaf type
Compound (Pinnately , Bipinnately, Palmately); Simple
Leaf arrangement
Opposite
Leaf shape
Cordate
Leaf margin
Lobed; Serrate
Leaf feel
Rough
Leaf size
3-6 inches long, 3-6 inches wide
Hairs present
Yes
Leaf detail
Mostly opposite, palmately 3-7-veined and -lobed. Leaves are pubescent with stiff hairs on the upper surface and along the veins on the lower surface, and with serrate margins. The petiole is usually longer than the blade.
Flower color
Gold/Yellow; Green
Flower form
Panicle
Flower shape
Cup
Flower size
1-3 inches
Flower detail
Female vines produce green hops. Flowers are produced in the axils of the leaves. Male and female flowers occur on separate plants (dioecious). Female flowers hang down in cone-shaped clusters; male flowers in upright panicles. The female inflorescence of overlapping bracts are green or purple, pubescent, with densely hairy margins. A pair of inconspicuous female flowers without petals is located at the base of each bract. Male flowers of 5 greenish or purplish sepals, no petals, and 5 anthers.
Bloom time
Fall; Summer
Fruit color
Gold/Yellow; Green
Fruit type
Achene
Fruit detail
The fruit is an ovoid, yellow-brown achene.
Stem color
Green; Purple/Lavender
Stem detail
Its rough stems are twining, green or purple streaked, 4-angeld, with stiff 2-branched stalked hairs that aid in climbing. Stems can reach lengths of 35 feet.
Wildlife & Ecology
Native status
Non-native
Origin
Eastern Asia; Russia south to North Vietnam
Distribution
Eastern Canada, mid-west and eastern United States, south to Georgia. Also parts of Europe.
Wildlife value
Food source for Gray Hairstreak, Eastern Comma, Question Mark, and Red Admiral butterflies. Honeybees collect the pollen from the female flowers.
Attracts
Bees; Butterflies; Pollinators
Play value
Attracts Pollinators; Buffer; Screening
Food & Medicine
Harvest time
Fall
Fruit type
Achene

Uses (ethnobotany)

An annual vine that can be used as screening.

Landscape Use
Landscape location
Slope/Bank
Landscape theme
Butterfly Garden; Pollinator Garden; Shade Garden
Design feature
Barrier; Screen/Privacy
Garden tags
#deciduous #drought tolerant #high maintenance #fast growing #annual vine #herbaceous #butterfly garden #herbaceous annual #annual #honey bees #butterfly caterpillar host #butterfly friendly #vine #aggressive #weedy #twining
Problems & Resistance
Problems
Contact Dermatitis; Weedy
Resistant to
Drought
Propagation
Seed
Poison severity
Low
Poison parts
Flowers; Leaves
Poison symptoms
SKIN IRRITATION MINOR, OR LASTING ONLY FOR A FEW MINUTES. Skin irritation with blisters upon contact.
Toxic principle
Volatile oils and bitter acids
Contact dermatitis
Yes
Toxicity summary
Low severity poison; parts: Flowers; Leaves; contact dermatitis

Planted at Hunnicutt

Nobody’s planted this one yet.