Members of the Rosmarinus plant genus are hardy perennials that reach from 90 cm to 1.8 m in height.
One of the more familiar members of Rosmarinus is the culinary herb Rosemary.
If you are growing Rosemary for use in cooking then the leaves can be used fresh at any time but it is best to harvest the leaves before the plant flowers if you plan to dry them. The Rosemary leaves should be dried in a dark area; once dried place the dried rosemary leaves in a Tupperware or similar container.
Rosmarinus species bloom towards the end of spring and the start of summer when they carry blue flowers; the leaves are narrow and oblong in shape and grow off of woody branches. Rosemary plants can be grown as part of a herb garden or as a container plant.
Rosmarin (Rosmarinus officinalis) by blumenbiene.
Rosmarinus officinalis 'Prostratus' by Wallygrom.
Common Names: Rosemary.
Life Cycle: Hardy perennial. Half hardy perennial.
Height: 36 to 72 inches (90–180 cm). Shrub.
Native: Mediterranean. Western Asia.
Growing Region: Zones 6 to 9.
Flowers: Species dependent: Late spring through to summer in cooler climates; blooms year long in warmer climates..
Flower Details: white, purple, blue, pink. Small.
Foliage: Evergreen. Needle-like, Oblong. Short. Fragrant. Green on top, white below.
Sow Outside: Usually grown from hardwood cuttings because seed germination and initial plant growth can be very slow and unreliable.
Seed: 1/4 inch (6 mm) Following the last frost. Spacing: Smaller species: 20 to 24 inches (50 to 60 cm); Larger species: 40 to 48 inches (100–120 cm).
Sow Inside: Germination time: three weeks. Temperature: 70°F (21°C). End of winter/Start of spring. Transplant outdoors following the last frost.
Requirements and care: Full sunlight (for best results) or partial shade. Excellent drainage. Sandy soil. Poor soil. Do not water. Do not feed. Soil pH 6.5–7.8. Thrives in dry soils. Will struggle in peat, clay and wet soil. Prune to keep tidy and to remove any frost damaged leaves. Propagate: by taking cuttings in the spring or autumn (take a soft shoot of about six inches (15 cm) in length, remove the bottom leaves, and plant into the soil. Bring potted plants indoors in cold areas.
Miscellaneous: The name Rosmarinus is derived from the Latin for 'dew (ros) of the sea (marinus). Fresh leaves can be harvested for culinary use at anytime. If you are planning to dry rosemary then remove the leaves before flowering occurs, dry in the dark, and keep in a sealed airtight container.
It is best to grow Rosemary from hardwood cuttings or from purchased plants; cuttings from Rosemary and other Rosmarinus Plants should be took in either the spring or autumn and started off indoors. They should then be put outdoors into a sunny part of the garden following the last frost of spring. It is best to space rosemary from 50 to 100 cm apart and they should grow in a sandy soil that is of pH 6 to 7.5. It is very important that the soil that rosemary and other Rosmarinus plants grow in is very well drained for best results.
It is possible, though quite difficult to grow Rosmarinus plant species from seed. The Rosemary seeds should be sown at a depth of 6 mm well before the last frost of winter / spring. The plants will grow very slowly so lots of patience is required if you plan to grow rosemary from seed.
Once established Rosemary takes very little looking after, for best results the soil should be poor and well drained; so do not fertilize or water. If you live in a cold area it may be a good idea to bring the rosemary plants indoors for the winter.