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American Cow-parsnip

Heracleum maximum

perennial herb View on Calscape

Care

Sun

part shade

Water

low

Soil

Fast, Medium, Slow; Tolerant of a variety of soils as long as sufficient moisture is provided.

Size

4–8ft tall

Bloom

Jun-Aug

Deer

Resistant

Edible

Young petioles and stems raw or cooked; traditional Indigenous use

Native Range

Riparian areas throughout California from the coastal regions to the Sierra Nevada, between sea level and 6000 ft elevation, extending north to British Columbia and east to the Rocky Mountains.

Care Guide

Planting

Plant your Cow-parsnip in partial shade in a location with fast, medium, or slow-draining soil - this plant is tolerant of a variety of soils as long as you provide sufficient moisture. The best time to plant is in fall or early spring to give it time to establish before summer. Space plants according to their mature size of 4–8 feet tall, keeping in mind they can spread and may self-seed.

After Planting

Water weekly through your first summer to keep the soil consistently moist, then gradually reduce watering frequency as the plant becomes established - Cow-parsnip needs low water once settled in. It flowers summer through August with no special pruning required. Be aware that chemicals in the plant can cause dermatitis in some people, so wear gloves when handling, and note that it may self-seed prolifically, so deadhead spent flowers if you want to prevent volunteer seedlings.

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