SEED ORDERS OVER $100 SHIP FREE!
Hypericum kalmianum

Kalm's St. John's Wort

$3.00 - $100.00

Packet
$3.00
1/8 oz.
$17.50
1/4 oz.
$30.00
1/2 oz.
$55.00
1 oz.
$100.00

New! Kalm's St. John's Wort is a small shrub topping out at just a few feet. Consider using it as a native hedge in a sunny, medium-moist site. 

Hypericum kalmianum - Kalm's St. John's Wort

Map Key

Present in state
Present but introduced in county
Present and native in county; not rare
Not present in state
Present and native in county; rare
Species extirpated (historic)
State or county listed as noxious
Present in state; exotic

This map shows the native and introduced (adventive) range of this species. Given appropriate habitat and climate, native plants can be grown outside their range.

Be the first to ask a question.

Seed

Growing your own plants from seed is the most economical way to add natives to your home. Before you get started, one of the most important things to know about the seeds of wild plants is that many have built-in dormancy mechanisms that prevent the seed from germinating. In nature, this prevents a population of plants from germinating all at once, before killing frosts, or in times of drought. To propagate native plants, a gardener must break this dormancy before seed will grow.

Each species is different, so be sure to check the GERMINATION CODE listed on the website, in the catalog, or on your seed packet. Then, follow the GERMINATION INSTRUCTIONS prior to planting. Some species don't need any pre-treatment to germinate, but some species have dormancy mechanisms that must be broken before the seed will germinate. Some dormancy can be broken in a few minutes, but some species take months or even years.

Seed dormancy can be broken artificially by prolonged refrigeration of damp seed in the process of cold/moist STRATIFICATION. A less complicated approach is to let nature handle the stratifying through a dormant seeding, sowing seeds on the surface of a weed-free site in late fall or winter. Tucked safely beneath the snow, seeds will be conditioned by weathering to make germination possible in subsequent growing seasons.

To learn more, read our BLOG: How to Germinate Native Seeds

Dormant Bare Root Plants

We dig plants when they are dormant from our outdoor beds and ship them April-May and October. Some species go dormant in the summer and we can ship them July/August. We are among the few still employing this production method, which is labor intensive but plant-friendly. They arrive to you dormant, with little to no top-growth (bare-root), packed in peat moss. They should be planted as soon as possible. Unlike greenhouse-grown plants, bare-root plants can be planted during cold weather or anytime the soil is not frozen. A root photo is included with each species to illustrate the optimal depth and orientation. Planting instructions/care are also included with each order.

Download: Installing Your Bare-Root Plants

Potted Plants

3-packs and trays of 32, 38, or 50 plants leave our Midwest greenhouses based on species readiness (being well-rooted for transit) and order date; Spring shipping is typically early May through June, and Fall shipping is mid-August through September. Potted 3-packs and trays of 38 plugs are started from seed in the winter so are typically 3-4 months old when they ship. Trays of 32/50 plugs are usually overwintered so are 1 year old. Plant tray cells are approximately 2” wide x 5” deep in the trays of 38 and 50, and 2.5" wide x 3.5" deep in the 3-packs and trays of 32; ideal for deep-rooted natives. Full-color tags and planting & care instructions are included with each order.

Download: Planting and Care of Potted Plants

This short-statured shrub is perfect for any home landscape! Kalm's St. John's Wort prefers full-partial sun and high-quality medium or medium-wet soils. It is endemic to the Great Lakes Region and is found in habitats including wet interdunal swales, borders of sandy ponds, and moist meadows.

Bees are the main visitors to their many bright yellow flowers, and enjoy the pollen when the flowers bloom in July and August. Other faunal associations are not common and white-tailed deer seldom browse this plant. 

Details

Seeds/Packet
1,000
Seeds/Ounce
350,000
Germination Code
A
D
Life Cycle
Perennial
Sun Exposure
Full, Partial
Soil Moisture
Medium-Wet, Medium
Height
2 feet
Bloom Time
July, August
Bloom Color
Yellow
USDA Zones
3-7
Plant Spacing
1-2'
Catalog Code
HYP42T