Rosemary ‘Blue Lagoon’ is a distinct and appealing cultivar, favored by gardeners for its unique aesthetic qualities and robust nature. Its visual charm and aromatic presence make it a popular choice for various garden designs.
Understanding Rosemary Blue Lagoon
Distinctive Features
Rosemary ‘Blue Lagoon’ features vibrant, deep blue flowers that appear profusely, creating a striking visual display. These blooms often cover the plant, forming a carpet-like effect from early spring into summer, sometimes re-blooming in autumn. Its foliage consists of narrow, dark green, needle-like leaves that are highly aromatic, releasing a pleasant scent when brushed against.
Growth Habit and Size
This rosemary cultivar exhibits a semi-prostrate or spreading growth habit, tending to spread outwards while also mounding up. It can sprawl informally over embankments or walls, making it suitable for cascading over edges. While often sold as a groundcover, it can eventually mound to a height of about 0.5 to 1 meter (1.5 to 3 feet) and spread significantly, sometimes reaching 2 to 3 meters (6 to 10 feet) wide under optimal conditions.
Hardiness and Climate
Rosemary ‘Blue Lagoon’ is a hardy evergreen perennial adapted to hot, dry conditions, reflecting its Mediterranean origins. It tolerates dry periods, coastal conditions, and moderate frost. This variety is reliably winter hardy in USDA Plant Hardiness Zones 6a through 11. However, consistently wet or extremely cold and windy conditions can negatively impact its roots and foliage.
Growing and Caring for Rosemary Blue Lagoon
Sunlight and Location
Rosemary ‘Blue Lagoon’ flourishes in full sun, requiring at least six to eight hours of direct sunlight daily for optimal growth and flowering. While it can tolerate partial shade, a sunny location encourages more prolific blooms and denser foliage. Selecting a site with good air circulation is beneficial, as this helps prevent fungal issues. Protecting the plant from cold, drying winds also contributes to its overall health.
Soil Requirements
Well-draining soil is essential for ‘Blue Lagoon’ rosemary, as it is sensitive to overly wet conditions that can lead to root rot. It prefers sandy or loamy soil and tolerates pH levels between 6.0 and 7.5 (moderately acidic to slightly alkaline). Amending heavy clay soils with grit or other drainage-improving materials ensures proper water runoff. The plant naturally thrives in open, nutritionally poor, and stony soils.
Watering Needs
Once established, ‘Blue Lagoon’ rosemary is drought-tolerant and requires minimal watering, often relying on rainfall. Overwatering is a common cause of decline, leading to root rot. During its first year, consistent watering is necessary for root establishment. For mature plants, water deeply but infrequently, allowing the soil to dry out completely between waterings, especially for those in the ground. Container-grown rosemary needs more frequent watering as their soil dries faster.
Pruning for Optimal Growth
Pruning ‘Blue Lagoon’ rosemary is beneficial for maintaining its shape, encouraging bushier growth, and promoting a continuous display of flowers. The ideal time to prune is in late spring, immediately after the main flush of blooms has faded. Light tip pruning of young plants encourages branching and a fuller form. For mature plants, annual hard pruning can help maintain size and shape, removing about a quarter to a third of the plant’s growth. It is important to avoid cutting into old, woody stems that lack leaves, as these often do not resprout.
Fertilizing
Rosemary ‘Blue Lagoon’ has modest nutritional needs and does not require heavy fertilization. Over-fertilization, especially with high-nitrogen fertilizers, can lead to lush but weak growth more susceptible to pests. If fertilization is necessary, a light application of a balanced, slow-release fertilizer in spring is sufficient.
Pest Management
This rosemary variety is resistant to many pests due to its aromatic oils. However, common garden pests like aphids, spider mites, and whiteflies can occasionally affect it. Good air circulation and proper watering practices help prevent many issues. For minor infestations, a strong spray of water can dislodge pests; for persistent problems, insecticidal soaps or horticultural oils can be used. Fungal diseases, such as root rot, are prevented by ensuring excellent drainage and avoiding overwatering.
Common Uses of Rosemary Blue Lagoon
Rosemary ‘Blue Lagoon’ serves multiple purposes, valued for both its culinary attributes and its ornamental appeal in the landscape. Its aromatic foliage is a significant draw for both uses.
Culinary Applications
The fragrant, needle-like leaves of ‘Blue Lagoon’ rosemary are prized for culinary use, adding a distinct pine-like aroma and flavor to various dishes. It is well-suited for flavoring roasted meats like lamb, pork, and chicken, and enhances the taste of roast potatoes. The leaves can be used fresh or dried and are also incorporated into stuffings, stews, and tomato sauces.
Ornamental and Landscape Uses
Beyond the kitchen, ‘Blue Lagoon’ rosemary is a versatile plant for garden design, offering year-round interest with its evergreen foliage and vibrant blue flowers. Its spreading growth makes it excellent for groundcover, allowing it to sprawl over embankments, walls, or rockeries. It also performs well in containers, patio planters, and hanging baskets, showcasing its cascading form. This variety is a popular choice for Mediterranean, cottage, and herb gardens, and its flowers attract pollinators like bees.