‘Tuscan Blue’ rosemary ( _Salvia rosmarinus_ ‘Tuscan Blue’, formerly _Rosmarinus officinalis_ ‘Tuscan Blue’) is a favored, fragrant, and adaptable herb. This cultivar features an upright growth habit, vibrant deep blue flowers, and a robust aroma. Its resilient nature and dual purpose for culinary and ornamental applications contribute to its widespread popularity.
Essential Growing Conditions
‘Tuscan Blue’ rosemary thrives in ample sunlight, requiring at least six to eight hours of direct sun exposure daily for optimal growth and strong aromatic oils. Insufficient light can lead to leggy growth and reduced flowering and fragrance.
Moderation is important for watering, as the plant prefers drier conditions. Established ‘Tuscan Blue’ rosemary is drought-tolerant, but young plants need consistent watering to develop a robust root system. Overwatering causes root rot, while underwatering may cause wilting and browning leaves.
The ideal soil is well-draining, with a slightly acidic to neutral pH (6.0 to 7.0). Sandy or loamy compositions are suitable, ensuring good aeration and preventing waterlogging. Heavy clay soils should be avoided or amended significantly to improve drainage.
‘Tuscan Blue’ rosemary tolerates heat well. It prefers moderate humidity and benefits from good air circulation to prevent fungal issues. Temperatures between 60-65°F are generally suitable, but it handles warmer outdoor conditions.
Rosemary is not a heavy feeder and requires minimal fertilization. A light application of balanced fertilizer in spring, or after flowering, is sufficient if growth appears poor. Over-fertilization can diminish the plant’s flavor and aroma.
Planting Your Tuscan Blue Rosemary
When planting ‘Tuscan Blue’ rosemary, select a sunny location with excellent drainage. This ensures the plant receives adequate light and prevents water from pooling around its roots.
For container planting, choose a pot with adequate drainage holes. A well-draining potting mix, ideally a blend of succulent/cactus mix and regular potting soil, provides necessary aeration. Start with a 6- to 8-inch container for young plants, repotting to larger sizes as the plant matures.
When planting in the ground, dig a hole twice the width of the root ball and about one inch shallower than the plant’s current soil level for proper drainage. If the native soil is heavy clay, amend it with sand or gravel to improve drainage. Space multiple plants at least 2 to 3 feet apart, as ‘Tuscan Blue’ can reach up to 6 feet tall and 4 feet wide. After planting, thorough watering helps settle the soil and establish the plant.
Pruning and Maintenance
Pruning ‘Tuscan Blue’ rosemary maintains its shape, promotes denser growth, and encourages new foliage. It also improves air circulation, reducing fungal disease risk. Regularly removing dead or damaged branches contributes to plant health.
The optimal time for significant pruning is late spring, after flowering. This allows new growth to harden off before colder months. Light maintenance pruning can occur throughout summer to preserve shape and vigor.
Tip pruning encourages bushiness by snipping new growth. Selective pruning helps shape the plant. Remove woody stems with care, as rosemary does not regenerate well from old, bare wood. Use clean, sharp pruning shears for precise cuts.
Harvesting and Practical Uses
Harvesting ‘Tuscan Blue’ rosemary involves cutting sprigs, focusing on new growth. Avoid over-harvesting any single section. Leaves can be used fresh or dried.
For storage, fresh sprigs can be kept in the refrigerator; drying or freezing are options for longer preservation. Its robust flavor makes it popular for culinary uses, enhancing dishes such as roasted meats, potatoes, bread, and infused oils.
Beyond culinary uses, ‘Tuscan Blue’ rosemary offers ornamental value with its upright habit and showy blue flowers, suitable for hedges or as a specimen plant. Its aromatic qualities also lend themselves to fragrant sachets.
Addressing Common Issues
‘Tuscan Blue’ rosemary is generally resilient, but can encounter issues. Pests such as aphids, spider mites, and whiteflies may occasionally appear. These can often be managed with insecticidal soap or a strong water spray.
Primary disease concerns are powdery mildew and root rot. Powdery mildew is linked to high humidity and poor air circulation. Root rot results from overwatering or poorly draining soil. Good air circulation and proper watering prevent these issues.
Environmental stressors can also impact the plant. Browning leaves might indicate underwatering, over-fertilization, or extreme cold. Leggy growth points to insufficient light. Addressing the underlying environmental factor is key for recovery.
Winter Care
‘Tuscan Blue’ rosemary is quite hardy, typically thriving in USDA zones 7b through 11. It can tolerate temperatures down to about 15°F (-9°C), or even 10°F (-12°C) in some cases.
In colder climates outside its hardiness range, grow ‘Tuscan Blue’ rosemary in containers to move indoors during winter. If planted in the ground in borderline zones, provide winter protection, such as heavy mulching around the base or covering the plant during severe freezes.
When bringing potted rosemary indoors, place it in a location with bright light, such as a south-facing window. During winter dormancy, significantly reduce watering, as the plant’s needs are much lower.