There are about 30 species of lavender, which can be found from the Canary Islands eastward into western India, and they are divided into 6 sections, of which 4 are significant as herbs. The plant is a woody-based sub-shrub and will rarely exceed 70 cm in height.
Both fresh and dried flowers are used in cooking – make sure that any flowers you use for culinary purposes have not been sprayed with garden chemicals. These flowers are one of the herbs that make up herbes de Provence .
All varieties of the plant require excellent drainage and full sun. They are better grown fairly hard, and a slow release fertilizer or a light application of organic compost is recommended. They are all suited to being grown in large pots. Varieties are propagated by cuttings, but species are seed sown in spring. Prune the plants annually, preferably in early spring. True and Intermedia varieties can be shaped during harvesting. Never cut back hard into old wood, or the plants may die.
Harvest true True and Intermedia flowers in midsummer when spikes are one to two-thirds open. Tie the stems in bunches and hand them upside-down to dry; strip them of their flowers. Lavender’s culinary applications are limited, although the flowers are edible. They are used in the Moroccan spice ras el hanout. Lavender goes well in sweet dishes containing cream, such as ice cream. It can be added to shortbread and icings and used in jams and jellies. Crystallize the flowers as edible cake decorations.
information sourced from The Complete Book of Herbs