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Great St. Johnswort
Hypericum pyramidatum

Blooming for about three weeks across July and August, Great St. Johnswort is an important nutrition source for pollinators. It thrives in moist, well-drained soils and in partial to full sun. Its foliage is somewhat toxic to mammals and a skin irritant.

USDA symbol: HYAS80

General Information

Plant TypeForb
Height3 to 4 feet
Light ExposureSun
Soil MoistureDry
Bloom ColorYellow
Great St. Johnswort (Great St. Johnswort<div><em class="small">Hypericum pyramidatum</em></div>)
Photo credit: Metro Blooms (Click to enlarge)


Flooding / Inundation ToleranceModerate
General Resilience6
Salt ToleranceMedium
Stress ToleranceDrought Tolerant, General Disturbance

Pollinator Value: High

Bloom MonthsJuly to September
Larval Host ofMoths
Specific Pollinators HostedAgonopterix lythrella, Melanchra assimilis, Nedra ramosula
Pollinator BenefitInsect Pollinated, Supports Generalists

Project Planning

Project TypeShoreline Buffer
Coefficient of Conservatism8
Herbivore SensitivityLow
Rate of SpreadMedium
Soil StabilizationDeep
Vegetative ReproductionClonal


CountyAitkin, Benton, Blue Earth, Brown, Cass, Chisago, Dakota, Dodge, Fillmore, Goodhue, Hennepin, Houston, Isanti, Itasca, Kanabec, Mille Lacs, Morrison, Mower, Olmsted, Pine, Ramsey, Renville, Rice, Sherburne, Sibley, St. Louis, Stearns, Wabasha, Washington, Winona, Wright
EcoregionDriftless Area, North Central Hardwood Forests, Northern Lakes and Forests, Northern Minnesota Wetlands, Western Cornbelt Plains
Approximate Eco ProvinceEastern Broadleaf Forest, Laurentian Mixed Forest, Prairie Parkland