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Sunny Boulevard® St. John's Wort

Hypericum kalmianum

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Sunny Boulevard® St. John's Wort

Discover More Information On Sunny Boulevard® St. John's Wort

The Sunny Boulevard® St. John's Wort, or Hypericum kalmianum, is a hardy shrub that brings a cheerful burst of color to any landscape. This North American native is well-suited for gardeners looking for a low-maintenance plant that offers a showy display of blooms and an easy-care profile. With its preference for full sun exposure, the Sunny Boulevard® basks in the glory of summer days, lavishing gardens with its vibrant yellow flowers from early to late summer.

Standing at a mature size of 2 to 3 feet in both height and spread, this deciduous shrub forms a mounded shape that fits splendidly in perennial borders, mass plantings, or as an eye-catching hedge. The yellow blooms not only add visual warmth to the garden but also serve as a magnet for bees, enhancing the biodiversity of the outdoor space. The foliage is equally attractive, with dark green, willow-like leaves providing a lush backdrop to the sunny blossoms.

Sunny Boulevard® St. John's Wort is a testament to resilience, being drought and salt tolerant, and is also known to resist deer, making it an excellent choice for a variety of garden settings. Its hardiness across zones 4 through 8 allows it to thrive in many climates, especially when planted in well-drained soils rich in sandy loams. The shrub requires minimal care, with northern gardeners advised to mulch the roots in winter, while feeding in early spring with a slow-release fertilizer can promote vigorous growth.

Plant Attributes

The Sunny Boulevard® St. John's Wort is a versatile and robust deciduous shrub that presents a medley of appealing attributes for any gardener. It is a medium-sized plant, typically reaching a garden height of 24 to 36 inches with a corresponding spread, creating a mounded and compact form that is as suitable for small garden spaces as it is for larger landscapes. The rich yellow flowers that it generously produces from early to late summer are a particular highlight, casting a warm glow and offering a continuous display of color throughout the season. These blossoms not only contribute to the aesthetic appeal of the shrub but also play an important role in supporting local pollinators such as bees.

The foliage of Sunny Boulevard® is equally impressive with its dark green leaves that present a striking contrast to the bright flowers, adding depth and texture to the plant's overall appearance. The shrub's adaptability is evident in its hardiness, withstanding winter cold in zones 4 through 8 and exhibiting tolerance to drought and salt, which is beneficial for gardens exposed to these challenging conditions. Its resilience to deer makes it a desirable choice for areas where wildlife browsing can be a problem.

Landscape Use

Sunny Boulevard® St. John's Wort, with its vivid yellow flowers and hardy disposition, serves multiple purposes in the landscape, offering both aesthetic appeal and practical benefits. Its uses in landscaping include:

  • Border Plantings: The compact and mounded habit of the Sunny Boulevard® makes it an ideal choice for border plantings, where it can provide a continuous edge of bright color throughout the summer months.
  • Mass Planting: When used en masse, this St. John's Wort creates a sea of yellow, transforming open spaces into a vibrant spectacle. It's particularly effective when planted in large numbers in public gardens or parks.
  • Mixed Shrub Borders: The plant's medium height and long bloom time make it a perfect middle-layer shrub in mixed borders, nestled between lower groundcovers and taller backdrop plants.
  • Foundation Plantings: Its neat appearance and moderate size allow it to fit snugly against foundations, enhancing curb appeal while not obscuring windows or architectural details.
  • Wildlife Gardens: The flowers attract bees and other pollinators, making it a valuable addition to gardens designed to support local ecosystems and promote biodiversity.
  • Hedges: Although not a traditional hedge plant, when planted in a row, Sunny Boulevard® can create informal low hedges that are alive with color and beneficial insects throughout the summer.
  • Drought-Tolerant Landscapes: Given its drought tolerance, it is well-suited to xeriscaping or water-efficient gardening, requiring minimal irrigation once established.
  • Coastal Gardens: The shrub's salt tolerance makes it a good fit for seaside landscapes where salty spray from the ocean can be a challenge for less hardy plants.
  • Erosion Control: Its root system can help stabilize slopes and banks, making it a functional choice for erosion-prone areas.
  • Winter Interest: Even after the blooms have faded, the plant's structure and seed heads can add interest to the winter garden.
  • Containers: Its mounded form and manageable size also make it suitable for large containers, where it can provide seasonal color on patios, balconies, or decking areas.

In addition to these landscaping uses, Sunny Boulevard® St. John's Wort requires little maintenance, making it a favored choice for both residential and commercial landscapes looking for attractive yet sustainable plant options.

Planting & Care

Sunny Boulevard® St. John's Wort (Hypericum kalmianum) is a low-maintenance, versatile shrub with specific planting and care requirements that ensure it thrives in a variety of settings.

Planting Instructions:

  1. Timing: Plant in spring or early fall to allow the root system to establish before extreme weather conditions, like intense summer heat or winter cold.
  2. Location: Choose a location that receives full sun to partial shade. Although it prefers full sun, it can tolerate part sun with slightly reduced flowering.
  3. Soil: It thrives in well-drained soils, preferably rich, sandy loams. However, it can adapt to a variety of soil types as long as they are not waterlogged.
  4. Planting Depth and Spacing: Dig a hole as deep as the root ball and two to three times as wide. Space the plants 2 to 3 feet apart to allow for mature spread.
  5. Watering: Water thoroughly at planting to settle the soil around the roots. During the first growing season, ensure it receives regular watering to establish a deep, extensive root system.
  6. Mulching: Apply a layer of mulch around the base of the plant to retain moisture, regulate soil temperature, and reduce weed competition.

Care Instructions:

  1. Watering: Once established, Sunny Boulevard® is drought-tolerant but will benefit from watering during prolonged dry spells, especially in extreme heat or if planted in containers.
  2. Fertilizing: Feed in early spring with a slow-release fertilizer formulated for trees and shrubs. Follow the label for the recommended rate of application.
  3. Pruning: Prune to shape as needed, ideally after flowering. Pruning will also encourage new growth and maintain a neat appearance.
  4. Winter Care: In the northern reaches of its hardiness zone, mulch the root zone to protect against freeze-thaw cycles and to minimize the risk of frost heave.
  5. Pest Management: While generally resistant to pests and diseases, keep an eye out for common garden pests and treat accordingly with eco-friendly options.
  6. Renewal Pruning: Periodically, you may perform renewal pruning to rejuvenate older shrubs by cutting back one-third of the oldest stems to the ground.

Following these planting and care guidelines will help ensure that Sunny Boulevard® St. John's Wort remains a healthy and vibrant part of your garden for many years. It's the plant's combination of beauty, resilience, and minimal care requirements that make it such an appealing choice for gardeners and landscapers alike.

Additional Information

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Sunny Boulevard® St. John's Wort


Plant Features

  • Plant Type: Shrub
  • Watering Needs: Average; more in extreme heat or containers.
  • Botanical Pronunciation: hy-PEER-ih-kum kal-mee-AY-num
  • Deciduous/evergreen: Deciduous
  • Growth rate: Moderate
  • Average landscape size: Mature size is 2-3' tall and 2-3' wide.
  • Special features: Attracts Bees, Deer Resistant, Drought Tolerant, Salt Tolerant, Winter Interest, Native to North America
  • Foliage color: Dark Green
  • Blooms: Summer
  • Flower color: Yellow
  • Flower attributes: Long Bloom Season, Showy Flowers
  • Garden style: Cottage, Rustic, Xeriscape
  • Design Ideas: Ideal for groupings, mass planting, and perennial or shrub borders. Its bright yellow flowers add vibrant summer color, making it perfect for sunny cottage gardens or mixed wildlife-friendly landscapes. Use in hedges or as a standalone plant in coastal and drought-tolerant gardens. Provides an excellent contrast when paired with purple-flowering plants or ornamental grasses.
  • Companion Plants: Black-eyed Susan, Purple Coneflower, Russian Sage, Ornamental Grasses

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