March 23, 2019
Cultivated for thousands of years for its beauty, fragrance and flavor, lavender is one of many Mediterranean plants that do well in the Bay Area. Once used in Egyptian perfumes and Roman baths, its name probably comes from the Latin verb lavare, meaning “to wash.” Introduced into England in the 1600s, it was prized by royalty for use in teas and jams.
Lavender is an evergreen, woody perennial or subshrub with a multitude of garden uses, from borders and walkways to containers and mass plantings. It is part of the mint family, along with other hardy, drought-tolerant plants such as salvia, rosemary and catmint.
Lavender is easy to grow, sun-loving and drought-tolerant. It resists most pests, including deer, yet is highly attractive to bees and butterflies. Flowers usually range from blue and lilac to deep purple, but there are some pink, white and yellow shades as well.
With more than 400 varieties, there are three main types of lavender, which vary in size, color, bloom time, and tolerance for heat and cold temperatures. Planting several different kinds can extend the bloom season and give your garden color from early spring into fall.
These are the first bloomers, beginning in early spring in warmer climates, and often continuing through summer. The common names are imprecise and somewhat confusing.
Spanish lavender (Lavandula stoechas) is also sometimes called French lavender because it grows there as well. It is low and wide, up to 2 feet tall and 3 feet across. It is heat- and drought-tolerant but somewhat frost tender. Foliage is needle-shaped and silvery, and flowers are recognizable for their large bracts, resembling butterfly wings. ‘Anouk’ and ‘Silver Anouk’ are examples.
Also called French lavender is L. dentata. Quite vulnerable to frost, it has toothed leaves, light purple flowers, and grows 2 to 3 feet tall and wide. ‘Goodwin Creek Grey’ (L. ginginsii) is a heartier hybrid.
The next to bloom, from late spring to mid-summer, is English lavender (L. angustifolia). The smallest of the lavenders, it is compact and dainty, ranging from 12 to 24 inches tall. Flowers may be intense blue or purple, and it is the most prized among lavenders for culinary use and the essential oils used in soaps and perfumes. English lavender is cold hardy but struggles with intense heat. ‘Munstead’ is one of the most heat-tolerant.
Lavandula x intermedia, also known as the lavandins, are the last to bloom. A cross between English (L. angustifolia) and Portuguese lavender (L. latifolia), lavandins are fast growing, heat- and drought-tolerant, and flower from mid- to late summer. Sporting long, gray leaves, they are the tallest lavenders, often up to 3 feet tall and wide. ‘Provence’ and ‘Grosso’ are well-known varieties.
Although unfussy and easy to grow, lavender has a few critical requirements — lots of sun, non-acidic soil (pH of 6 to 8) and excellent drainage. Heavy clay soils should be amended with coarse compost to improve drainage. Planting on slopes or berms will also help.
New plantings need consistent moisture for the first year or two but should never be soggy. Established plants are drought-tolerant but bloom best with some water. Fertilize lightly with compost or a slow-release fertilizer once a year in early spring. Too much fertilizer leads to excess foliage and fewer flowers.
After the second year, plants can be cut back by about a third in early spring to encourage new growth. This is especially helpful for lavandins, which if left alone may sprawl and become woody. Don’t prune into the wood at the base of the plant, because it will not regrow. A second pruning after flowering, lightly shearing blossoms and stems, will encourage re-bloom.
Most lavenders live for five to seven years, but, properly tended, they may reward you with their beauty for years longer.