Lavender

Description

Lavender is the name given to several species of herbaceous, perennial shrubs in the genus Lavandula which are grown as ornamental plants or for essential oil. Lavender plants are small, branching and spreading shrubs with grey-green leaves and long flowering shoots. The leaves can be simple or pinnate measuring 30–50 mm (1–2 in) in length. The plant produces flowers on shoots or spikes which can be 20–40 cm (8–16 in) long. The flowers are lilac or blue in color. Lavender can grow to 0.4 m (1.3 ft) in height and live for 20–30 years. Lavender may also be referred to as true lavender, medical lavender, smelling lavender, thin-leaved lavender or English lavender and is believed to originate from the Mediterranean, Middle East and India.


Uses

Lavender flowers can be used in cooking as a herb or used to produce lavender sugar. Fresh flowers can be used as a flavoring in desserts and sauces. Bees which collect lavender nectar produce a high quality honey. Lavender is also cultivated as an ornamental plant or for the extraction of essential oil. The flower spikes are popularly dried and used in flower arranging.


Propagation


Basic requirements
Lavender grows very well in a wide range of climates, and optimally at temperatures between 7 and 21°C (44.6–69.8°F). Lavender plants require bright sunlight for adequate growth and should be positioned accordingly. The plants will grow best in light to sandy, well-draining soils with a pH of 5.8–8.3. The plants are drought tolerant once established but require regular watering while they establish.

Propagation
Lavender is usually propagated vegetatively from cuttings or by dividing the mother plant. Cuttings are best taken directly after the plants bloom. The cuttings should be taken from stems with no flower buds and should be prepared for planting by removing the leaves at the bottom of the stem. The cuttings should then be planted in pots containing a high quality, sterile potting soil and watered regularly until they root. the cuttings should develop a root system of their own in approximately 3 weeks.

Planting
Lavender plants can be planted Spring through to Fall. If planting in the Fall, care should be taken to use larger plants with an established root system to allow the plants to establish in the soil quickly before winter sets in. Spring planted lavender can be smaller as it can establish over the summer. Rooted cuttings can be planted directly in the garden after they have been hardened. Plants should be spaced 0.5–1.0 m (2–3 ft) apart depending on the variety, allowing 1–2 m (3–6 ft) between rows.

General care and maintenance
Once established, lavender requires little care. It benefits from prompt harvest if the flowers are to be used for further processing. Faded blooms should be removed to promote further blossoming. Light pruning encourages the plant to branch. Care should be taken not to over water the plants by allowing the plants to dry out between waterings.

Harvesting
Flowerheads can be harvested from the plant at any time. Flowerheads to be used for the extraction of essential oil are best harvested when only 1/2 to 1/3 of the florets are open. Harvesting is usually done by hand but may be achieved mechanically in commercial production. after harvest, the flowers should be hung upside down in bunches to dry out.




References

Adam, K. L. (2006). Lavender production, products, markets and entertainment farms. National Sustainable Agriculture Information Service. [Accessed 31 January 15]. Free to access.

Geisel, P. M., Unruh, C. L. & Lawson, P. L. (2004). Lavenders for California Gardens. University of California Division ofAgriculture and Natural Resources. [Accessed 31 January 15]. Free to access.

Kimbrough, K. A. & and Swift, C. E. Growing Lavender in Colorado. Colorado State University Extension. Available at: http://www.ext.colostate.edu/pubs/gar.... [Accessed 31 January 15]. Free to access.



Common Pests and Diseases

Root rot
Phytophthora spp.
Pythium spp.
Rhizoctonia spp.

Symptoms
Wilting leaves; yellow leaves; dying leaves; discolored root tissue
Cause
Oomycete
Comments
Disease favors cold wet soils
Management
Avoid over-watering plants; plant lavender in well-draining soils