Light Needs
Mature Height
Mature Spread
Growing Zones
This small deciduous shrub will provide texture and color to your garden with its small blue-green leaves and bright yellow pin cushion-shaped flowers in July and August. The narrow bluish leaves and yellow clusters of flowers create a nice color contrast. This plant will attract numerous bees and butterflies. It’s a great choice for a pollinator garden or plant one near your vegetable garden to attract pollinators to that area of your yard.
Blues Festival Hypericum kalmianum 'SMHKBF' reaches 2 to 3 feet tall and wide in full sun conditions in USDA hardiness zones 4 to 7. The plant produces multiple stems and grows in a mounded shape that’s filled out close to the ground. This North American native plant is deer and drought resistant and salt tolerant.
Blues Festival St. John's Wort Care
Blues Festival St. John's Wort can be planted along roadways and salt-treated walkways without being stunted or killed by the potential salty runoff. It’s resistant to powdery mildew, leaf spot and leaf scorch. It’s low maintenance and should only be pruned after flowering if needed. Flowers appear on new growth. Do not cut this plant back to the ground.
Blues Festival St. John's Wort Spacing
This plant can be used as a specimen plant, in mass plantings, in perennial gardens, in border gardens and as a container plant. Space plants 2 to 4 feet apart on center. This plant may be less tolerant to cold if the container is left outdoors during the winter.
Blues Festival® St. John's Wort Plant Facts
Growing Conditions
- Hardiness ZonesGrowing Zones
- USDA Zones 4 to 7 (perennial); grown as an annual elsewhere (outdoors year-round); grown indoors elsewhere (outdoors year-round); grown in containers elsewhere (grown as a seasonal crop)
- Sun Exposure
- Full Sun (6+ Hours Direct Sun)
- Mature Height
- 2-3 Feet
- Mature Spread
- 2-3 Feet
- Growth Habit
- , Mounded
- Water Needs
- Average
Flowers & Foliage
- Flower Colors
- , Yellow
- Flower Description
- Yellow
- Bloom Time
- Late Spring to Early Summer
- Blooms On
-
New Wood
?
"Blooms on" tells you which stems produce flowers, which decides when it's safe to prune.
- New Wood: Flowers form on stems that grow this season. Prune in late winter or early spring without losing blooms.
- Old Wood: Flower buds form on last year's stems. Prune right after flowering. Pruning in fall or early spring removes next year's blooms.
- Both New and Old Wood: Blooms on last year's stems and again on new growth, so it flowers even after a hard winter or a mistimed pruning. Prune lightly after the first flush of blooms.
- When to Prune
- Late winter to early spring, before new growth starts
- Foliage Color
- , Blue, Green
- Foliage Description
- Blue & Green
- Foliage Type
- , Deciduous
- Seasonal Interest
- , Summer Flowering, Fall Interest, 3 Season Interest
Garden Benefits
Plant Overview
- Common Name
- Blues Festival®, St. John's Wort
- Also Known As
- Kalm's St. John's Wort
- Botanical Name
- Hypericum kalmianum 'SMHKBF' USPP 25,795
- Brand
- Proven Winners
- Plant Type
- Deciduous
Simple Plant Spacing Calculator
Please Note: The pictures below are to give a general representation of the different container sizes. The actual size/ages of plants are estimates and will vary based on type of plant, time of year, last pruning & many other factors.
Also Known As:
Quart
Plant Age:
~ 6 months - 1 year
Plant Size:
~ 4"-8"
Pot Size:
~ 4.75"H x 4.5"W
Volume:
1.50 quarts
Also Known As:
2.5 Quart Pot
Plant Age:
~ 1 - 2 years old
Plant Size:
~ 8"-12"
Pot Size:
~ 6.5"H x 6.5"W
Volume:
2.20-2.30 quarts
Also Known As:
#1 Container
1 Gallon
Plant Age:
~ 1 - 2 years old
Plant Size:
~ 10"-14"
Pot Size:
~ 7"H x 7.75"W
Volume:
2.26-3.73 quarts
Also Known As:
#2 Container
2 Gallon
Plant Age:
~ 1.5 - 3 years old
Plant Size:
~ 12"-18"
Pot Size:
~ 9.5"H x 9.5"W
Volume:
1.19-1.76 gallons
Also Known As:
#3 Container
3 Gallon
Plant Age:
~ 2 - 4 years old
Plant Size:
~ 12"-30"
Pot Size:
~9.5"H x 11"W
Volume:
2.32-2.76 gallons
Also Known As:
#5 Container
5 Gallon
Plant Age:
~3-4 years old
Plant Size:
~ 20" - 60"
Pot Size:
~11" H x 10 1/2” W
Volume:
3.5 - 4 gallons
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We want your plants to arrive in great condition! If you notice any issues upon delivery, contact us within 3 days.
Starting January 1, 2026 all bushes, perennials & trees purchased come with an extended 1-year warranty for added confidence. If your plant dies due to a health issue within a year, we’ll make it right.
Plants that are currently in stock typically ship within 2-7 business days after your order is placed.
Plant Addicts ships to the lower 48 states within the U.S. Unfortunately, we do not currently ship to Alaska, Hawaii, or internationally.
This plant cannot be shipped to the following states: AK, HI. These restrictions apply only to this specific plant due to agricultural regulations or other limitations. Other plants may still be available for shipping to these states.
If you have any questions about shipping restrictions, feel free to reach out to our team!