Safety warning — high hazard
All parts of the plant — leaves, stems, roots, and bare winter vines — can cause an itchy, blistering rash
Poison Ivy
Toxicodendron radicans
A native but prohibited plant known for the saying 'leaves of three, let it be.' Its oil (urushiol) causes an itchy, blistering rash on contact. It grows as a low plant, a small shrub, or a climbing vine.
Poison ivy — 'leaves of three': three leaflets, the middle one on a longer stalk.
Image source: Ontario weed-identification reference (OMAFRA / Ontario CropIPM)
At a glance
- Key clue
- 'Leaves of three'; reddish spring growth; red-orange in fall
- Best months
- May to October, when the three-leaflet pattern is clearest — but never test by touching
- Often found
- Fence line, Ravine edge, Vacant lot
- Easiest to remove
- Spring (smaller plants) — with full protection
Why it's prohibited
Poison ivy is a direct health risk: touching any part of the plant can cause an itchy, blistering allergic rash, and the oil lingers on tools, clothing, and pet fur. Because it grows where people walk and play, it must be controlled on private property.
Main identification features
- Clusters of three leaflets — the middle one on a longer stalk ('leaves of three')
- Leaflet edges can be smooth, toothed, or slightly lobed; surface may be glossy
- Reddish new leaves in spring, green in summer, red-orange in fall
- Small clusters of greenish-white berries
- Grows as groundcover, a low shrub, or a hairy climbing vine on trees and fences
Similar plants & look-alikes
- Virginia creeper — Virginia creeper usually has five leaflets (not three) and blue-black berries; it's not poison ivy.
- Boxelder seedlings — Young boxelder also has leaflets in threes but they grow opposite each other on the stem, and it lacks the longer middle-leaflet stalk.
- Fragrant sumac — Fragrant sumac has three leaflets too, but the middle leaflet has little or no stalk and the plant is aromatic.
Month-by-month identification timeline
May to October, when the three-leaflet pattern is clearest — but never test by touching.
April–May (Early spring)
· 10–40 cmNew leaves emerge reddish and glossy, in the classic clusters of three.
Reddish, glossy 'leaves of three'.
May–June (Late spring)
Leaves turn green; plants spread as groundcover, low shrubs, or climbing vines.
Green leaflets in threes; middle leaflet on a longer stalk.
June–August (Summer)
Full green foliage; small greenish-white flowers then berries form.
Three-leaflet clusters; greenish-white berries.
September–October (Fall)
Leaves turn bright red and orange — colourful but still potent.
Vivid red-orange fall leaves (still cause rash).
Winter (Dormant)
Leaves drop; hairy climbing vines remain on trees and fences and can still cause a rash.
Bare hairy vines — still hazardous to touch.
Growth-stage photo gallery
Photos of poison ivy at different growth stages — note the visual features described under each one to identify it confidently.
New compound leaves with three reddish, glossy leaflets — 'leaves of three.'
A compound leaf with three leaflets, the middle one on a longer stalk (petiole).
A cluster of poison ivy plants growing along a woodlot edge.
Round, greenish-white berry-like fruit clusters.
Click any photo to enlarge. Image source: Ontario weed-identification reference (OMAFRA / Ontario CropIPM).
How to remove it safely
Safety first. Recommended if you are sensitive to poison ivy, or for large patches and climbing vines on trees and structures.
Safest resident-friendly approach
Only attempt removal if you are not sensitive and can fully protect your skin. Wearing waterproof gloves, long sleeves, and long pants, dig or pull the plant out with the roots when the soil is moist, ideally in spring or early summer. Bag everything. Wash all skin, tools, and clothing afterward, since the oil stays active. If you react strongly to poison ivy, have someone else or a professional do it.
Tools & protection
- Waterproof / chemical-resistant gloves
- Long sleeves and long pants
- Closed shoes
- Spade
- Bags
- Soap for washing afterward
Best time of year
Spring to early summer, when plants are smaller and soil is moist.
Monitoring
Watch for resprouts and new seedlings; the oil remains active on any leftover roots and stems.
Prevent regrowth
Remove roots fully and monitor; resprouts and new seedlings should be removed promptly with the same precautions.
What not to do
- NEVER burn poison ivy — the smoke carries the oil and can severely harm your lungs and eyes
- Don't touch it with bare skin, and don't let the oil sit on tools, gloves, or clothing
- Don't weed-whip it, which can spray oil and plant bits
Disposal
Double-bag the plant material and put it in the garbage — never compost or burn it. Keep the bagged material away from skin contact.
Safety cautions
- All parts of the plant — leaves, stems, roots, and bare winter vines — can cause an itchy, blistering rash
- Wear waterproof gloves, long sleeves, and long pants; avoid all bare-skin contact
- Never burn poison ivy; the smoke is hazardous to breathe
- If exposed, wash skin with soap and cool water as soon as possible, and clean tools and clothing
When to get professional help
Recommended if you are sensitive to poison ivy, or for large patches and climbing vines on trees and structures.
Double-bag and garbage all material; never burn or compost. The oil stays active, so clean everything that touched the plant.
Sources
Report a prohibited plant
Found this plant growing on a property? Report it to the City through official Toronto 311.
Report through Toronto 311This page is provided for general educational and reference purposes only. Plant identification results are not a legal determination. Always confirm prohibited plant information using official City of Toronto resources. For hazardous species or large infestations, consider seeking professional advice.
Image credits & usage
Plant photographs are reproduced for non-commercial public education and identification reference only. Sources include Ontario weed-identification (OMAFRA / Ontario CropIPM) and invasive-species fact-sheet materials; all image rights remain with their respective owners. If you are a rights holder with a concern, please contact us through the Feedback page. Photos on this page: Ontario weed-identification reference (OMAFRA / Ontario CropIPM). Contact us.