Shrub · Vitaceae
Boston Ivy
Parthenocissus tricuspidata
Grown for leaves that burn crimson in fall, set on masonry to climb rather than your siding.
Full sun
Every 7–14 days
USDA 4–8
30–49 ft · 9–15 m
Overview
Boston ivy carries broad, glossy, three-lobed leaves on long stems, and across a season those green blades shift to deep crimson-red and purple as autumn cools. It is a member of the grape family rather than the true ivies, with origins in eastern Asia. The vine is tough and fast growing, holding through cold to USDA zone 4 and heat near 100°F (38°C).
Its grip is the detail to study up close. Rather than twining, each tendril branches into clusters of small swollen pads, the adhesive disk-tipped holdfasts, that press flat and cement themselves to almost any surface, so one plant can sheet an entire wall. That same adhesion is the catch, since the pads bond to paint, shingles, and mortar and tear away messily, so the vine belongs on masonry, stone, a fence, or a trellis rather than wood siding.
Behind the showy foliage sits an easy plant. It thrives in full sun or deep shade, drinks little once its roots take, and rarely needs feeding. The main task is reining in its vigorous growth with a hard prune each year so the dense leaf cover stays off windows, gutters, and the roof.
Care
The short version: plant it in average, well-drained soil in sun or shade, water it through the first season and rarely after, and prune it hard each late winter so its fast, leafy growth stays off the walls and roof.
Light
Boston ivy grows across the full range, from full sun to full shade. Sun draws the deepest, most saturated fall color from the leaves, while in heavier shade the blades still fill in but the autumn tones come muted.
Water
While a young vine is still knitting its roots into the ground, wait until the soil feels dry through its upper half before offering more. Mature growth shrugs off drought, the woody stems carrying their broad leaves through most conditions on nothing more than a deep soak every 7 to 14 days in dry weather.
Soil
Almost any well-drained soil works, including clay, sandy, and rocky ground. It accepts a wide pH range from 5.5 to 7.5, which is part of why it grows in so many places.
Temperature
Hardly any climber tolerates such a spread. The woody stems ride out winters of -29°F (-34°C) and summers that reach 100°F (38°C), a range spanning USDA zones 4 through 8 with nothing extra needed to shield the plant.
Humidity
Outdoor humidity suits it fine, so there is nothing to measure. Air movement matters more than moisture in the air, since still, crowded growth invites leaf spot and mildew on the foliage.
Feeding
Fertilizer barely figures in this vine's life, since its own vigor drives out yard after yard of leafy stem unaided. Should new growth ever stall, a single spring dose of balanced general-purpose fertilizer gets the shoots moving again.
Pruning
Plan on a hard prune in late winter or early spring to keep the fast, leafy growth in check. Cut it back off windows, gutters, roofs, and wood siding before the new leaves push out.
Repotting
This plant sinks its roots into open garden soil far more often than a pot. A container-grown specimen wants fresh quarters every 2 to 3 years, or earlier once roots coil visibly around the root ball, the stems stop extending, or water pours straight out the bottom.
Size & spacing
Given something to climb, it reaches 30 to 50 feet (9 to 15 m) tall and spreads 5 to 10 feet (1.5 to 3 m) wide. Plan for that reach and the support its leafy stems will cover before you plant.
When to plant
Boston ivy is woody and perennial, so there is no seed-starting rush. Set young plants out in spring or fall while the soil is workable, let the leafy stems lengthen over the seasons, and look for its tiny, easy-to-miss June-to-July flowers ahead of the crimson-to-purple blaze of fall leaves.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Spring or fall
- Harvest: June to July (flowers inconspicuous); brilliant crimson-red to purple fall foliage
Hardiness
USDA hardiness zones: 4–8
Temperature: down to -34°C
Troubleshooting
Most trouble with Boston ivy shows up in one of two places: the pads gripping the wall, or the broad leaves themselves. Read the close-up signs and you can redirect the vine or treat the foliage before damage spreads. Match what you see below, then act while it still helps.
Tiny gripping pads on the wall that lift paint and shingles
Look closely at a clinging stem and you will see adhesive disk-tipped holdfasts, small swollen pads at the tips of branching tendrils that fasten flat to the surface. They hold so tightly that pulling a vine away strips paint and leaves a smear of residue, and the dense mat of stems and leaves presses damp against the wall while creeping under shingles and into mortar. Set the vine on masonry, a rock wall, a fence, or a sturdy trellis, and cut the stems at the base first so the little pads shrivel and lose their grip before they are scraped off.
Fix:
- Do not grow on wood, shingle, or painted surfaces; redirect onto masonry, rock walls, fences, or sturdy trellises
- Cut vines at the base and allow holdfasts to dry and weaken before gentle removal
- Scrape or sand off remaining residue and refinish damaged surfaces
Dark-spotted, chalk-dusted, or lace-chewed leaves
When fungal leaf spot and powdery mildew take hold in still, crowded, humid growth, the glossy green blades pick up dark sunken blotches and a pale chalky dusting across their surface. Japanese beetles, scale, and leafhoppers chew between the veins until the leaf is reduced to a lacy skeleton. Thin the growth so air slips through the canopy, water at the base to keep the blades dry, lift the beetles off by hand, and coat lingering scale with horticultural oil.
Fix:
- Improve air circulation and avoid overhead watering to reduce fungal disease
- Hand-pick Japanese beetles and treat scale or heavy infestations with horticultural oil or an appropriate insecticide
- Remove and dispose of heavily diseased foliage
Toxicity
This is not a plant to nibble. Both the lobed leaves and the small blue-black berries hold insoluble calcium oxalate crystals and oxalic acid, needle-fine crystals that sting the mouth and irritate the gut. Keep pets, livestock, and children from chewing the foliage or eating the berries, which carry the higher risk.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
The needle-fine oxalate crystals jab a cat's mouth the instant its teeth break a leaf or berry, so expect drooling, pawing at the face, and an upset stomach with vomiting or loose stool.
Dogs Mild
A dog that has crushed the foliage or berries between its teeth drools and turns from its food, and the raw, irritated mouth often comes with vomiting or diarrhea soon after.
Horses Mild
The same sharp crystals scratch at a horse's mouth and gut, so a grazed mouthful brings drooling, oral soreness, and a dull, off-feed look.
Rabbits Mild
A rabbit is best kept clear of it, since the oxalates prick and burn the soft mouth and can leave the animal drooling, off its food, and nursing a sore digestive tract.
Livestock Mild
Cattle, goats, and sheep rarely browse it, but a chewed mouthful of leaves or berries rasps the mouth and gut and leaves the animal salivating and off its feed.
Birds Caution
The small blue-black berries are the riskiest morsel, so keep caged birds well away from the plant rather than letting them peck at it.
People Caution
No part of this plant is food. A bitten leaf or berry stings the mouth and unsettles the stomach, so keep curious children away from the foliage and fruit.
Keep pets and children from chewing the foliage or eating the berries, which are the higher-risk part.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
A few named selections recast the plain green with different leaf shapes and colors. These are the ones you are most likely to find.
Veitchii
Its leaves run smaller and unfurl in purple to bronze tones in spring before deepening to red in fall.
Fenway Park
Its foliage glows golden chartreuse to lime-yellow before scattering into a multicolored autumn display.
Lowii
Its leaves are small, curly, and deeply lobed, flushing crimson once fall arrives.
How to propagate
Boston ivy is easy to multiply, and three methods are open to you depending on your patience and the time of year.
Stem cuttingsEasy
Softwood cuttings in early summer or hardwood cuttings in late fall to winter · 4 to 8 weeks to root
Cuttings give the fastest new plants. Take soft, pliable green stems in early summer or firm, woody ones from late fall into winter, and they push roots in 4 to 8 weeks. Where a trailing stem already rests on the soil, pin it down and let it root in place.
LayeringEasy
Spring through summer · Several weeks to a few months
Layering is the simplest route with this vine. Press a low stem flat against the soil any time from spring through summer, and roots form along its underside over several weeks to a few months before it is cut from the parent.
SeedModerate
Sow after cold stratification in late winter or spring · Several weeks to germinate
Seed asks for more patience. Squeeze the seeds free of the pulpy berries, give them a cold spell to break dormancy, then sow in late winter or spring and watch for sprouts over several weeks. The cold stratification is the step that makes germination happen.
Myths
Boston ivy is a true ivy.
The leaves may look ivy-like, but this is no ivy at all. Boston ivy belongs to the grape family, Vitaceae, which makes it a far closer cousin to grapes than to the true ivies in the genus Hedera.