French lavender is native to hot dry Mediterranean regions and is thought to have been cultivated for over 400 years. It's also called everblooming lavender because it blooms from spring until frost. It has grey-green serrated edge leaves and unique blue-purple flowers which are actually bracts (modified leaves) cradling small clusters of flowers. This particular lavender has a lighter scent than other varieties and is not a common culinary ingredient.
French lavender can grow in just about any type of soil, but thrives in loose sandy potting soil that has been enriched with manure before planting. Plants should be spaced about 60 to 90 cm (2 to 3 feet) apart to ensure they have plenty of room to grow and are not overcrowded. Plant lavender in a sunny location where it is protected from winds and extremely cold conditions. French lavender is hardy, thriving in warm conditions but is the least frost hardy of the different varieties. To protect during the winter months, grow lavender near the base of a sunny wall or, if you live in colder climates, in a container which can be taken inside in winter.
Water, fertiliser and mulch
Water lavender plants deeply once or twice a week. Don't water too much. One or two buckets of water every two to three weeks works well. Feed your plants with a slow release granular fertiliser that has higher nitrogen and potassium content; the first and third number on the label, respectively. These nutrients increase foliage and flower growth for a fuller, healthier plant. Mulch around plants to within 5 cm (2 inches) of main stem to help control weeds and retain moisture in the soil.
Pests, pruning and harvesting
French lavender is most susceptible to aphids and cochineals. Aphids will leave a sticky white substance and tiny holes in the leaves while signs of cochineal infestation is a reddish scaly substance. An easy treatment is to clean the leaves with a cotton swab dipped in rubbing alcohol. Prune plants every year after blooming to extend the life and create a fuller blooming plant. To keep French lavender looking its best, keep cut back to no more than 80 cm (3 feet) in height, including the flowers. When pruning, be sure to cut back the grey leaf stems as well as the bright green flower stems. If you want to harvest your lavender flowers, the best time is as soon as the flowers turn a bright vivid purple colour. They will be a shade of grey until the flowers open up. Cut the flowers in the cool morning and if drying, tie the flower stems together with twine and hang upside down in a cool area.