Shrub · Aristolochiaceae
Dutchman's Pipe
Aristolochia macrophylla
A fast, heavy climber that throws up a wall of overlapping leaves and feeds the pipevine swallowtail.
Full sun
Every 5–10 days
USDA 4–8
20–30 ft · 6.1–9.1 m
Overview
Dutchman's pipe is a vigorous native woody vine grown for one thing above all: a dense green screen. Its large, overlapping heart-shaped leaves layer into solid cover over a porch, arbor, or pergola in a season or two, and the small pipe-shaped flowers that give it its name hide among them in late spring. It earns its keep fast and asks for very little once it has a foothold.
It is also one of the most important wildlife plants you can grow. The vine is the main host for the pipevine swallowtail, whose caterpillars feed on the leaves and store the plant's natural toxin to make themselves unpalatable to birds. Plant it where you want both shade and butterflies, and don't reach for a spray when the chewing starts.
Treat it as an ornamental and nothing else. Every part holds aristolochic acid, a compound that ruins kidneys and causes cancer in people, so it has no place in the kitchen or the medicine cabinet. Grown outdoors on a strong support and pruned each winter, it stays handsome and trouble-free for years.
Care
The short version: full sun to part shade, rich soil kept steadily moist, a sturdy support it can't pull down, and a hard cutback each late winter to keep its fast growth in bounds.
Light
Dutchman's pipe takes full sun to part shade and grows densest with plenty of light. Push it into deep shade and the screen thins out, leaving you weak, sparse growth instead of solid cover.
Water
Keep the soil consistently moist, because this vine has no tolerance for dry ground. Water it through dry spells, and aim to soak it roughly every 5 to 10 days while it settles in. Mulch over the roots holds the moisture it wants.
Soil
Plant it in rich, well-drained loam with plenty of organic matter dug in. It isn't fussy about pH, taking anything from 6.0 to 8.0, so the bigger job is keeping the ground moist and fertile.
Temperature
This is a tough plant, hardy across a wide range from about -29°F to 95°F (-34°C to 35°C). That cold-hardiness is what lets it grow as a perennial vine all the way up into zone 4.
Humidity
Ordinary outdoor air suits it, so there's no humidity to manage. Steady soil moisture matters far more to this vine than anything happening around its leaves.
Feeding
Feed lightly in spring with a balanced fertilizer or some compost worked in around the base. This vigorous native rarely needs much, and rich soil will often carry it on its own.
Pruning
Prune hard in late winter to hold its fast, heavy growth in check and keep the leaf screen tidy. It takes a hard cutback well, so don't be timid, and thin tangled stems to let air move through.
Repotting
This is a ground vine, not a container plant, so repotting rarely comes up. If you're holding a young one in a nursery pot, move it on before the roots circle and water starts running straight through.
Size & spacing
Give it real room and real support, because it climbs to 20 to 30 feet (6 to 9 m) and spreads 15 to 20 feet (4.5 to 6 m) wide. A single plant covers a large arbor, so site one well rather than crowding several.
When to plant
Dutchman's pipe is a hardy vine for zones 4 to 8 with no real planting season to stress over. Start seed in late winter to early spring after a cold spell, or sow it outdoors in fall, then set young plants out in spring once the frost is gone and the soil works. The small pipe flowers come in late spring, around May and June.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter to early spring (seed needs cold stratification); can also direct sow outdoors in fall
- Plant: Spring after last frost, once soil is workable
- Harvest: Late spring (May to June), with small pipe-shaped flowers hidden among the foliage
Hardiness
USDA hardiness zones: 4–8
Temperature: down to -34°C
Troubleshooting
There is little to go wrong with a settled Dutchman's pipe, and the few issues you'll meet are about size and siting rather than disease. Read the leaves and the support, and most problems sort out with a sharp pruning or a better spot. The one thing that looks like trouble, chewed leaves, is usually a good sign.
The vine outgrows its space and drags down its support
This is just an overgrown vigorous vine doing what it does, climbing 20 to 30 feet and packing on a heavy screen of leaves faster than most trellises can hold. Cut it back hard in late winter to renew the framework and thin the tangle, and give it a substantial arbor or pergola from the start. A flimsy support will sag or bend under the weight.
Fix:
- Prune hard in late winter to reduce size and renew the framework
- Provide a sturdy, substantial support (heavy trellis, arbor, pergola, or strong wires) rated for a heavy woody vine
- Thin tangled stems to improve airflow and keep the screen tidy
Thin, sparse foliage and weak, stunted growth
A Dutchman's pipe that grows thin and weak is usually telling you the soil is too dry for it, since it has no tolerance for drought. Deep shade and poor, hungry soil drag it down too. Keep the ground steadily moist with a layer of mulch, work in compost, and site it in full sun to part shade for the densest screen.
Fix:
- Keep soil consistently moist; mulch to conserve moisture
- Site in full sun to part shade for best density
- Improve soil with compost/organic matter
Leaves chewed or stripped by dark, orange-spotted caterpillars
Those are pipevine swallowtail caterpillars, and their feeding is a feature of this plant, not a problem. The vine is their main larval host, and the larvae pull aristolochic acid from the leaves to make themselves poisonous to birds. Leave them be. A healthy, established vine grows right back after defoliation, and you can plant a few extra if you want both the butterflies and full leaf cover.
Fix:
- Do NOT spray or remove the caterpillars - leaf feeding is desirable, not a pest problem
- Tolerate the chewing; a vigorous, established vine readily recovers from defoliation
- Plant extra vines if you want both butterflies and full leaf cover
Toxicity
Treat this plant as poison from root to flower. Every part carries aristolochic acid, a potent kidney toxin and proven human carcinogen, so it must never be eaten or brewed into any remedy. A casual nibble may only upset a pet's stomach, but no part is safe for people or animals, and you should keep children and grazing livestock well away.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Toxic
A cat that nibbles the leaves may drool and vomit, but the danger that matters is the aristolochic acid, which damages the kidneys. Keep cats from chewing any part.
Dogs Toxic
A dog chewing the foliage can drool and bring up its stomach, and the same kidney-harming compound is at work. Treat any real meal of the plant as a vet call.
Horses Toxic
Horses should never browse this vine. The aristolochic acid that runs through every part is a kidney poison, so fence it well away from where they graze.
Rabbits Toxic
Don't let rabbits near the leaves or stems. The toxin offers them no safe dose, and there is no edible part to share.
Livestock Toxic
Cattle, goats, and sheep face the same kidney damage from the aristolochic acid in the foliage. Keep this vine out of pastures and away from fence lines they can reach.
Birds Toxic
The whole plant is unsafe for birds to eat. One striking exception lives outdoors on its own terms, where pipevine swallowtail caterpillars store the toxin and turn it against the birds that would prey on them.
People Caution
No part of this plant is food or medicine. The aristolochic acid in it is a proven kidney poison and a known human carcinogen, so never brew it into a tea, tincture, or remedy, and wash your hands after pruning.
Grow as an outdoor ornamental only. Never consume any part and never use it in teas, tinctures, or herbal remedies - aristolochic acid causes irreversible kidney damage and cancer. Keep pets and children from eating the leaves, stems, fruit, or roots; wash hands after pruning.
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 pipevines turn up under the Dutchman's pipe name, and the choice matters for both leaf size and the butterflies. These are the ones worth telling apart.
Aristolochia macrophylla (syn. A. durior)
This is the classic native Dutchman's pipe, with very large smooth heart-shaped leaves that overlap into a dense shade screen and small pipe-shaped flowers, yellowish-green with brownish-purple lobes, tucked away among them.
Aristolochia tomentosa (woolly Dutchman's pipe)
A smaller native cousin from the central and southern states, it carries woolly hairs all over its leaves and stems and serves the pipevine swallowtail just as well as the larger species.
Aristolochia littoralis / A. elegans (calico or elegant Dutchman's pipe)
Skip this showy non-native, because it works as an egg-trap where female pipevine swallowtails lay eggs but the larvae starve rather than feed, so plant the native species instead wherever the butterfly lives.
How to propagate
Dutchman's pipe multiplies easily, whether you have the patience for seed or want a faster copy from the plant you already grow.
SeedModerate
Sow in fall outdoors or stratify and start in late winter/early spring · 1-2 seasons to a well-rooted young vine; several years to mature size
Dutchman's pipe sets seed freely, and a cold spell improves germination, so sow it outdoors in fall or stratify it and start in late winter to early spring. Expect a young, well-rooted vine in a season or two, and several years before it reaches full size.
Stem cuttingsModerate
Take softwood/semi-ripe cuttings in late spring to summer · 1-2 months to root, then grow on
Take softwood or semi-ripe cuttings from late spring through summer for a reliable copy of the parent vine. They root in a month or two, after which you grow them on before planting out.
LayeringEasy
Spring to summer · One growing season for rooted layers
The easiest route is layering, since the long flexible stems root wherever they touch moist soil. Pin one down from spring through summer and it gives you a rooted plant in a single growing season.
Myths
The caterpillars stripping the leaves are pests to spray or pick off.
Those are pipevine swallowtail larvae, and this is their host plant. They pull aristolochic acid out of the leaves to make themselves poisonous to predators, so the chewing is exactly what the vine is for. Leave them alone and let a vigorous plant grow back the leaves on its own.
Since butterflies thrive on it, the plant must be safe to eat or brew.
The very compound the caterpillars exploit, aristolochic acid, is a potent kidney poison and a Group 1 human carcinogen. It causes irreversible kidney damage and urinary tract cancers. No part of this plant is ever safe to eat or use as a remedy.
Any pipevine, native or not, helps pipevine swallowtails.
Some non-native species, such as the calico flower A. littoralis, work against the butterfly. Females lay eggs on them, but the larvae usually fail to survive. Plant the native pipevines, A. macrophylla or A. tomentosa, if you want to feed the swallowtails.
Sources
- NC State Extension Gardener Plant Toolbox
- Missouri Botanical Garden Plant Finder
- NC State Extension Gardener Plant Toolbox
- ASPCA Animal Poison Control (Toxic and Non-Toxic Plants list)
- University of Florida IFAS Extension (Featured Creatures, Pipevine Swallowtail Battus philenor)
- NIH/NCBI PMC (Systematic Overview of Aristolochic Acids: Nephrotoxicity, Carcinogenicity, and Underlying Mechanisms)