How much sun does Kalm's st. john's-wort need?

Kalm's st. john's-wort grows best in full sun conditions.

When does Kalm's st. john's-wort bloom?

Kalm's st. john's-wort blooms in July and August.

Where is Kalm's st. john's-wort native?

Kalm's st. john's-wort (Hypericum kalmianum) is native to IL, IN, MI, MN and 3 more states, per the World Checklist of Vascular Plants (Kew).

What pollinators does Kalm's st. john's-wort attract?

Kalm's st. john's-wort draws bees.

Kalm's st. john's-wort

Name: Pollinator Patch
Author: Pollinator Patch

Hypericum kalmianum

Last reviewed: October 2026

Kalm's st. john's-wort (Hypericum kalmianum) is a perennial shrub native to IL, IN, MI, MN and 3 more states. It blooms in July and August. The flowers draw bees.

Toxicity unknown

Kalm's st. john's-wort (Hypericum kalmianum) 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

medium

Size

24"–36" H × 24"–36" W

Bloom

Jul, Aug

Native to

IL, IN, MI, MN and 3 more states

Pollinators

bees

Before you buy

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Browse plants for this ecoregion

Northern Lakes and Forests North Central Hardwood Forests Driftless Area Southeastern Wisconsin Till Plains Central Corn Belt Plains Southern Michigan/Northern Indiana Drift Plains Huron/Erie Lake Plains Northeastern Coastal Zone Eastern Great Lakes Lowlands

A compact rounded shrub with narrow blue-green leaves and bright yellow flowers with prominent tufted stamens through summer. Tolerates both wet and dry rocky sites without losing its neat form.

Growing Kalm's st. john's-wort

Grow Kalm's st. john's-wort in full sun and medium water. Mature plants reach 24 to 36 inches tall and spread 24 to 36 inches wide.

Wildlife value

Pollen-rich flowers are visited heavily by bumble bees and other native bees.

Common questions

How much sun does Kalm's st. john's-wort need?: Kalm's st. john's-wort grows best in full sun conditions.
When does Kalm's st. john's-wort bloom?: Kalm's st. john's-wort blooms in July and August.
Where is Kalm's st. john's-wort native?: Kalm's st. john's-wort (Hypericum kalmianum) is native to IL, IN, MI, MN and 3 more states, per the World Checklist of Vascular Plants (Kew).
What pollinators does Kalm's st. john's-wort attract?: Kalm's st. john's-wort 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

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