Planting Guide: Cow Parsnip (Heracleum maximum)
Tip: Grow it as a bold, moisture-loving accent and butterfly host — and when you harvest the young spring stalks, wear gloves and peel them, since the sap can irritate skin in sunlight.
When Your Plant Arrives
Open the box promptly. Your plant travels dormant — no leaves and no soil — which is normal and the healthiest way for it to ship. Keep the roots moist and cool, and unwrap them only when you’re ready to plant. Aim to get it into the ground or a pot within a day or two; if you can’t, tuck the roots into damp soil, sawdust, or a bucket of moist material and hold it somewhere cool and out of frost. Don’t let the roots dry out or sit in standing water. If anything looks amiss, please contact customer service within 7 days of delivery and we’ll make it right.
Choosing a Site
Light: Sun to part shade.
Soil: Rich and moist; it likes damp ground.
Space: 2–3 ft apart; it is large and self-seeds.
Planting Steps
Plant in spring or fall.
Set at the depth it grew, backfill with compost, firm, water in, and mulch.
Watering & Care
Establishment: Keep moist.
After establishment: Wants steady moisture; dies back and returns each year.
Maintenance: Deadhead to limit self-sowing.
Protection
Handling (important): The sap contains compounds that, on skin exposed to sunlight, cause a burning, blistering rash (phytophotodermatitis). Wear gloves and long sleeves when handling or cutting it, keep the sap off your skin, and if you do get sap on you, wash it off promptly and keep that skin out of the sun for a day or two.
Wildlife: Flowers feed many pollinators.
Harvest Basics
Safety (essential): Cow parsnip is in the carrot family, alongside the deadly poison and water hemlocks and the dangerous giant hogweed — be certain of your ID, and handle only with gloves (see above).
Season: Young, tender leaf- and flower-stalks in spring, before flowering.
Prep: Peel every piece (gloves on) to remove the phototoxic outer skin, then eat raw or cooked — crisp and celery-like. Never eat any part unpeeled, or from a plant you cannot positively identify.
