How much sun does Hemp-agrimony need?

Hemp-agrimony grows best in full sun conditions.

When does Hemp-agrimony bloom?

Hemp-agrimony blooms in February, March, April, and May.

Where is Hemp-agrimony native?

Hemp-agrimony (Marah oregana) is native to CA, OR, WA, per the World Checklist of Vascular Plants (Kew).

Hemp-agrimony

Name: Pollinator Patch
Author: Pollinator Patch

Marah oregana

Last reviewed: September 2026

Hemp-agrimony (Marah oregana) is a perennial vine native to CA, OR, WA. It blooms in February, March, April, and May. The flowers draw bees.

Toxicity unknown

Hemp-agrimony (Marah oregana) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

Light

full sun

Water

low

Size

120"–360" H × 120"–360" W

Bloom

Feb, Mar, Apr, May

Native to

CA, OR, WA

Pollinators

bees

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Browse plants for this ecoregion

Coast Range Puget Lowland Marine West Coast Forest Northwestern Forested Mountains Central California Foothills and Coastal Mountains North American Deserts

A fast-growing herbaceous vine that climbs by tendrils from a large underground tuber. Small white star-shaped flowers appear in early spring, followed by a spiny round fruit; the vine dies back to the root each summer.

Growing Hemp-agrimony

Grow Hemp-agrimony in full sun and low water. Mature plants reach 120 to 360 inches tall and spread 120 to 360 inches wide.

Wildlife value

Early spring flowers provide nectar for bees before the vine dies back for the dry season.

Common questions

How much sun does Hemp-agrimony need?: Hemp-agrimony grows best in full sun conditions.
When does Hemp-agrimony bloom?: Hemp-agrimony blooms in February, March, April, and May.
Where is Hemp-agrimony native?: Hemp-agrimony (Marah oregana) is native to CA, OR, WA, per the World Checklist of Vascular Plants (Kew).
What pollinators does Hemp-agrimony attract?: Hemp-agrimony draws bees.

Native range data from the World Checklist of Vascular Plants (Kew). Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

If something looks wrong

Common plant problems, and what to check first

These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.

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