Toxicodendron radicans

Poison Ivy

At a Glance

TypeVine
FoliageDeciduous
HeightVariable: 6 inches-50+ feet (15 cm-15+ m)
WidthVariable: indefinite spreading
Maturity5 years

Growing Zones

USDA Hardiness Zones

3 - 10
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Maintenancehigh

Overview

Toxicodendron radicans is a deciduous woody vine, shrub, or ground cover in the Anacardiaceae family, highly variable in growth form — it may climb trees to 50+ feet (15+ m) via adventitious aerial rootlets, grow as a free-standing shrub 3–6 feet (90–180 cm) tall, or spread as a ground-hugging mat. Leaves are alternate, trifoliate ("leaves of three"), with leaflets 2–5 inches (5–13 cm) long — the terminal leaflet on a distinctly longer petiolule (stalk) than the two lateral leaflets. Leaflet margins are variable: entire, toothed, or lobed, sometimes all on the same plant. Leaves emerge reddish-bronze in spring, mature to glossy dark green, and turn bright scarlet, orange, or yellow in autumn. Small yellowish-green flowers are borne in axillary panicles 1–3 inches (2.5–8 cm) long in late spring. Fruit is a round, waxy, off-white to grey drupe 0.2 inch (5 mm) in diameter, borne in clusters, persisting through winter. All parts of the plant — leaves, stems, roots, flowers, and fruit — contain urushiol, a mixture of catechol-derivative oils that causes allergic contact dermatitis in approximately 85% of the human population. Urushiol remains active on dead plant material, tools, clothing, and pet fur for months to years. Burning the plant produces urushiol-laden smoke that can cause severe respiratory inflammation if inhaled. The species is ecologically important — fruit is consumed by over 60 bird species, and the foliage supports numerous moth and butterfly larvae.

Native Range

Toxicodendron radicans is native to eastern North America, from Nova Scotia and Quebec west to British Columbia and south to Florida, Texas, and Mexico. It occurs in forests, woodlands, thickets, fence rows, stream banks, and disturbed ground from sea level to approximately 5,000 feet (1,500 m). Several subspecies span the geographic range.

Suggested Uses

Not planted intentionally. In ecological context, the species is a native component of eastern North American forests and provides food for over 60 bird species (drupes) and numerous insects (foliage). In habitat restoration, its presence is tolerated in non-public-access areas as part of the native plant community. In managed landscapes — parks, trails, gardens — identification and removal are the primary management goals.

How to Identify

Identified by the alternate, trifoliate leaves with the middle leaflet on a longer stalk than the two lateral leaflets — the classic "leaves of three, let it be" mnemonic. Climbing forms are identified by the hairy-looking aerial rootlets covering the vine, giving it a fuzzy appearance on tree trunks. Distinguished from Parthenocissus quinquefolia (Virginia creeper) by the three (not five) leaflets. Distinguished from Rhus aromatica (fragrant sumac) by the climbing habit and the longer middle leaflet stalk. Young leaves may be confused with Acer negundo (box elder) seedlings, which have opposite (not alternate) leaves.

Appearance

Size & Dimensions

Height6" - 50'
Width/Spread1' - 10'

Reaches mature size in approximately 5 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~3 weeks
J
F
M
A
M
J
J
A
S
O
N
D
Small yellowish-green flowers in axillary panicles 1–3 inches (2.5–8 cm) long open from May through June. Bloom is inconspicuous. Pollinated by bees, flies, and other insects. Off-white to grey waxy drupes develop by late summer, ripening in September–October and persisting on the vine through winter. Drupes are an important winter food source for birds.

Detailed Descriptions

Flower Description

Yellowish-green (inconspicuous)

Foliage Description

Reddish-bronze (spring), glossy dark green (summer), scarlet-orange-yellow (autumn)

Growing Conditions

Sun Requirements

Requires 2-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.0 - 7.5(Neutral)
357912
Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

2-3 years to climbing form

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Not cultivated intentionally. For management and removal: wear long sleeves, pants, nitrile gloves (urushiol penetrates latex), and eye protection. Cut climbing vines at the base and apply concentrated glyphosate (20–25%) or triclopyr to the cut stem surface immediately. Do not pull vines — this releases urushiol from damaged roots and stems. For ground-level plants, apply targeted foliar herbicide during active growth (May–August). Never burn poison ivy — urushiol in smoke causes severe respiratory exposure. Wash all tools, clothing, and exposed skin with cold water and a grease-cutting soap (e.g. dishwashing liquid or Tecnu) within 30 minutes of contact to remove urushiol before dermatitis develops. Urushiol remains active on unwashed surfaces for 1–5 years.

Pruning

Not applicable for ornamental purposes. For removal, see care guide above. Dead vines on tree trunks still contain active urushiol — remove with full protective equipment or leave in place until degraded.

Maintenance Level

high

⚠️ Toxicity Warning

Toxic to pets and humans