Text by Pam Geisel and Michelle Strange, Master Gardener Advisors Emeritus
Lavender is a delightful and useful garden plant. It can be used as a drought-tolerant low hedge, specimen plant, cut flower and an herb that provides a fragrant addition to any garden. As garden ornamentals, lavenders have attractive gray-green foliage and eye-catching, long-lasting blooms.
Many uses: The name “lavender” comes from the Latin lavare, meaning “to bathe.” Hence, it has a strong association with cleansing, aromatic pleasure and burning of incense to clean the air. Lavender was used by the Egyptians in mummification, the Romans in their bathhouses, and medieval monks in tonics and laundries.
In terms of its herbal uses, the flower consists of a volatile oil that contains several organic constituents. Medicinally, these chemicals act to aid digestion, increase superficial blood circulation, and have been used as antispasmodics and antidepressants. Lavender, with its cool, relaxing scent, is also used as a natural sleep aid.
In culinary use, flowers from English lavenders are used in herbal teas, cookies and ice cream, but lavender’s best uses are in cosmetics and fragrances. Lavender is used in aromatherapy, as a relaxant and as an antiseptic. Its oils are prized for soap fragrances, aromatic baths, potpourri and sachets, facial oil, massage oil, floral water, compresses, perfume, facial steam and inhalation.
Taxonomy: Lavender is in the mint family and belongs to the genus Lavandula. The nomenclature of lavenders describes the leaf shape. English lavender, “L. angustifolia,” is a narrow-leafed variety, while “L. latifolia” is broad-leafed, and “L. x intermedia” is a hybrid between L. angustifolia and L. latifolia, having intermediate leaf characteristics.
The numerous cultivars of English lavenders include dwarf forms (Compacta and Compacta Nana), pink-flowered (Jean Davis or Lodden Pink), blue-flowered (Graves, Grey Lady and Irene Doyle), and the large purple-flowered selections (Twickel, Purple Hidcote, Munstead and Vera). Lavender Lady is excellent for garden use. Hidcote and Royal Velvet hybrids yield shorter-stemmed flowers but retain an excellent blue color when dried. Temperatures during the drying period have a significant effect on the final flower color since higher ambient temperatures can cause a bleaching effect.
Growing: Lavenders are native to the Mediterranean areas of Europe, which experience warm, dry summers and cool, rainy winters. They grow best in full sun in well-drained gravelly soils with low fertility. Excessive nitrogen encourages soft, succulent growth leading to plants breaking apart in the center. They will not tolerate wet, poorly drained soils. In soils that have slower drainage, consider planting on mounds to drain excess water away from the root crown.
Irrigation is needed, however, in dry areas while the plants are being established. Drip irrigation systems are recommended since overhead watering tends to break the plants apart and promotes disease. A soil pH of 6.5 to 7.5 is best.
Prune lavenders as you harvest the flower stalk. In a garden situation, even if you are not planning to harvest the crop, the best time to prune is just after the plants have completed their flowering cycle.
Problems: The most frequent problems associated with lavenders are related to root and crown rots, usually the result of too much water or poor drainage in heavy soils. Excessive irrigation during summer months, overhead watering and too much moisture near the main stem can also lead to root, stem and crown rot. When using drip irrigation, place the emitters several inches away from the stem.
Lavenders are not often bothered by insect pests, although they may occasionally attract spittlebugs. These insects are not usually a problem unless the plants are being grown for cut flowers and the spittle is in the flower heads.
The fall is the best planting time of the year in the southern San Joaquin Valley and a great time to plant Mediterranean-adapted plants. Planting several varieties of lavenders will give your garden a long blooming season with no pests, little water and ancient beauty.
So put lavenders on your shopping list and keep them in mind for fall planting. For more information on drought-tolerant gardening and irrigation tips, visit the MG website: ucanr.edu/sites/UC_Master_Gardeners/.