The shrubby St. John’s wort (Hypericum prolificum) is a fabulous flowering shrub for gardens across much of North America. With its dense foliage, bright yellow blooms, and adaptability, this plant provides multi-season interest along with ecological benefits. Both beginning and experienced gardeners will find it easy to grow.
An Overview of Shrubby St. John’s Wort
Typically reaching 3-4 feet tall and wide, shrubby St. John’s wort thrives in full sun to partial shade. It produces cheerful clusters of small, yellow flowers from early summer into fall. The blooms give way to interesting seed pods.
Hardy in zones 3-8, this shrub handles cold winters as well as hot, humid summers. It grows well in average garden soils with medium moisture but also tolerates clay, sand, periods of drought, and short-term flooding. Once established, it is rarely damaged by deer or rabbits.
Beyond the landscape appeal, shrubby St. John’s wort hosts moth and butterfly caterpillars It also attracts many pollinators to its flowers while providing food and shelter for birds.
How to Grow Shrubby St. John’s Wort from Seed
You can grow shrubby St. John’s wort from seed bare root plants, or potted nursery starts. Seeds are the most affordable option and let you propagate lots of new plants. Follow these tips
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Sow fresh seeds in late fall or after cold stratifying them in the fridge over winter. They need light to germinate.
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Gently press seeds onto the soil surface then cover lightly with compost or vermiculite. Keep evenly moist but not saturated.
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Germination occurs within 10-14 days at consistent 55°F soil temperatures.
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Transplant seedlings when they reach 2-3 inches tall. Harden off before planting outside.
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Grow the young shrubs in pots until they reach about 6 inches, then transplant to their permanent spot.
What to Expect with Bare Root and Potted Nursery Stock
Mail order nurseries like Prairie Moon Nursery offer shrubby St. John’s wort as dormant bare roots and actively growing potted plants:
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Bare roots are dug while dormant and shipped in spring or fall. They establish quickly when planted in cool weather.
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Potted plants come in 3-packs or trays of 32-50 starts. These are ready to plant anytime the soil can be worked.
Buying nursery plants provides instant gratification but availability is limited to their inventory.
How to Plant and Care for Shrubby St. John’s Wort
Follow these tips to help your new shrubby St. John’s wort thrive:
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Select a site with at least 4 hours of direct sun daily and decent drainage. Amend poor soils.
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Space plants 3-4 feet apart. Follow planting instructions from the supplier.
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Water regularly until established (1-2 inches weekly). Then water only during drought.
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Apply mulch to conserve moisture and reduce weeds.
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Prune lightly in early spring to shape and thin out old stems. Avoid shearing.
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Divide overgrown shrubs in spring or take stem cuttings to make new plants.
Design and Landscaping Uses
Shrubby St. John’s wort is extremely versatile. Here are some ideas:
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Use it as a medium-height, informal flowering hedge.
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Feature one or more as specimen plants in perennial or native gardens.
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Plant several together for a bright mass of color in a bed or border.
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Include it in a rain garden, meadow, or wildlife habitat area.
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Tuck one into a landscape island, buffer strip, or erosion control planting.
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Grow in a large pot on a patio for up close enjoyment.
Preventing Potential Problems
Shrubby St. John’s wort is not prone to many issues, but watch for:
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Poor flowering in too much shade. It needs at least 4 hours of sun.
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Leggy growth with inadequate light or air circulation. Improve conditions.
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Root rot in heavy, soggy soils. Enhance drainage and avoid overwatering.
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Leaf spot during humid weather. Promote air flow and remove affected leaves.
Why Grow Shrubby St. John’s Wort?
With its beauty, durability, wildlife benefits, and adaptability, shrubby St. John’s wort earns a spot in many more gardens. This tough, pollinator-friendly shrub thrives in diverse climates and conditions. Add its cheerful color and eco-functions to your landscape!
Next Steps
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View the Missouri Botanical Garden’s plant finder profile to learn more about growing and caring for shrubby St. John’s wort.
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Read Stone Post Gardens’ guide for additional tips on incorporating it into gardens and landscapes.
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Check Prairie Moon Nursery’s offerings to purchase seeds, bare root plants, or potted nursery starts.
With the right growing conditions and care, shrubby St. John’s wort will reward you with years of multi-season beauty and environmental benefits. This adaptable, wildlife-friendly shrub deserves wider use across North America!
What’s the Next Step?
Picked out your plants? View our Resource Guide of garden centers, seed sources, landscapers, education resources, and more!
Where Should I Start?
Check out the Grow Native! Committee’s Top Ten picks of native plants for a particular purpose.
Hypericum Hidcote St.John Wart
FAQ
How big do shrubby St John’s wort get?
Shrubby St. John’s wort (Hypericum prolificum) typically grows to be 2-4 feet tall and wide. It can sometimes reach up to 5 or 6 feet in height.
What is the difference between St John’s wort and shrubby St John’s wort?
Shrubby St. John’s wort and common St. John’s wort (Hypericum perforatum) are both members of the same genus, Hypericum, but they have distinct characteristics. Shrubby St. John’s wort is a shrub with woody stems, while common St. John’s wort is a perennial herb.
Where to plant shrubby St. John’s Wort?
Shrubby St. John’s wort (Hypericum prolificum) is adaptable and can be planted in various locations, thriving in full sun to partial shade and tolerating a wide range of soil types, including sandy, clay, and even dry soils.
What are the best uses for shrubby St. John’s Wort?
Consider planting Shrubby St. John’s Wort in rewilding projects, along borders, fences, foundations, medicinal plant gardens, pollinator gardens, slopes, along forest margins, or near foundations. An excellent choice in areas with compacted or thin, rocky soils.