Nothing delights my wife and me more than sitting on a sun-warmed bench watching bees and butterflies rush from lavender to lavender. We love the way lavenders look, the way they scent the air when we brush against them, the way that pollinating insects converge endlessly on their flowers throughout the summer. And our marauding deer leave them alone. We simply wouldn’t have a garden without them.
There are about 30 species of lavender, all members of the genus Lavandula. Most are native to the lands around the Mediterranean Sea. These do well in places with similar climates, like California, and struggle in areas such as the Southeast. Thankfully, the large diversity of lavenders offers a range of acceptable growing conditions, and while you can’t grow all lavenders everywhere, there is a type for almost everyone. All it takes is a little knowledge and planning.
Lavenders by Region
The most popular lavenders are English (Lavandula angustifolia), spike (L. latifolia), and a group of hybrids between these two, called lavandins (L. xintermedia). These are the sweetly scented lavenders of Elizabethan knots, English cottages, Shaker fields, and the colorful perennial borders of Gertrude Jekyll. They are grown on farms for lavender oil production and cut flowers. There are many cultivars available, all with grayish green foliage and tall, straight stems of long, dense flower spikes. They are the most cold-hardy lavenders, and they do great in hot, dry summers. They do poorly in areas that combine heat with high humidity to promote the biggest lavender killers: fungal diseases. But gardeners in such climates have several other options: French (L. dentata), Spanish (L. stoechas), and fernleaf (L. multifida).
Visitors to our garden usually don’t recognize fernleaf lavender as a lavender. It has deeply divided fernlike foliage and an earthy aroma that reminds us more of herbs like hyssop or catnip. It blooms continuously its first year, and we often grow it as an annual. It can only be grown as a perennial in the warmest parts of the country.
French lavender is a tender plant with a blocky flower spike topped by a small tuft of pale purple bracts. Its leaves are slightly indented all along their margins, as if they were cut out with pinking shears. Both flowers and foliage are thickly redolent with the scent of lavender and camphor. It is always in flower when given enough light and warmth, and it looks fabulous in a container. There are also three French hybrids that, because of their breeding, offer a bit more of the traditional lavender look and fragrance, yet still do well in humidity. Lavandula xallardii is a cross between French and spike, L. xheterophylla between French and English, and ‘Goodwin Creek Grey’, our own introduction, between French and woolly (L. lanata). All have retained the French habit of continuous bloom, and the latter two are also a bit more cold hardy.
The last good choice for humid areas is Spanish lavender (L. stoechas). Its flowers are similar to those of French, but with much larger and more colorful top bracts. And it’s hardier, too. The growth is distinctively low and sprawling; the scent is lavender mixed with pine.
Caring for Lavender Plants
Gardeners in all regions should provide lavenders the same growing conditions: full sun and a well-drained soil with a pH between 6.5 and 7.5. We recommend at least five hours of direct sun each day, although some afternoon shade is best in hot summer climates. Avoid dense planting in humid areas, because crowding will promote diseases. Space lavenders far enough apart to maintain good air circulation: two to three feet for English and Spanish cultivars and three feet or more for lavandins, French, and the French hybrids.
Consistently wet soil creates fungal problems. Soils can be amended by digging fine gravel or chicken grit, a crushed granite material fed to chickens, into the top 12 inches. Unlike some other rock amendments, these don’t compact the soil over time. An even better practice is to plant in beds or mounds raised a few inches above the soil grade. This increases both soil drainage and air circulation. We don’t mulch with organic matter, but instead use white sand or fine gravel. These rock mulches also reduce the localized humidity by reflecting sunlight up into the plants.
Lavenders do not demand a lot of water, but it is important to keep the soil evenly moist the first season or two. Once the plants establish a good root system, watering should be drastically cut back. Drip irrigation is ideal for lavenders. Overhead watering is fine in the dry western states, but increases fungal problems in humid areas. If you must water overhead, do it early in the day, so the foliage and flowers can dry out before nightfall.
Lavenders are not heavy feeders, but do require fertilizer, especially during the first three years of growth. A fertilizer that is roughly equal in its proportions of N-P-K is best. We use a blend of two parts commercially composted chicken manure and one part kelp meal. About half a pound of this mix is dug into each planting hole, and another half pound is scraped into the soil around each plant in subsequent springs. As an added bonus, chicken manure possesses an antifungal component.
We shape all of our lavender plants lightly in early spring just before new growth begins and again in midsummer after we harvest or deadhead the flowers. We avoid severe pruning unless absolutely necessary, as it sometimes is with broken limbs or dead branches. Lavenders don’t reliably sprout new growth from cuts made on old woody stems.
Garden Design with Lavenders
We especially favor the darkest, boldest purples among the English and Spanish. The much taller lavandins have longer stems and larger, lighter flower spikes that add grasslike vertical elements to the landscape. The white-flowered forms are quite stunning and show off well against a background of dark foliage. All are dramatic in large masses or drifts, or as small focal points in a mixed bed or border. The flowers of some cultivars are rather subdued and add more texture to the garden than they do color.
Most lavenders bloom for only four to six weeks each year, so it is important to consider growth habit and foliage as much as flowers when choosing cultivars. There are a number of hybrids of woolly lavender, like ‘Silver Frost’ and ‘Sawyers’, that have exceptionally silvery foliage. The creamy white and green leaf variegations of L. angustifolia ‘Goldburg’ and L. xintermedia ‘Walberton’s Silver Edge’ offer another color choice. The dentate leaves of French and its hybrids make them a good option for adding fine texture.
The English lavenders, the lavandins, and the woolly lavender hybrids can be clipped into edgings, neat mounds, or low hedges. Some cultivars are easier to keep trimmed than others, and of course there are large differences in heights and widths. Spanish lavenders are tough to tame and must be appreciated for their sprawling, more natural appearance. They look especially nice spilling onto pathways or in rockeries.
Finally, regardless of where you garden, all lavenders grow well in pots and tubs. Terra-cotta pots are the simplest way to try growing English lavenders and lavandins in very humid areas. The increased air circulation reduces the humidity around the plants and you can better control moisture in the soil. In cold climates, the tender types can be overwintered as potted plants in a greenhouse, sunroom, or south-facing window. French lavender makes great topiary standards and is quite long-lived. Our oldest specimen, the parent of ‘Goodwin Creek Grey’, just passed away into the compost pile at the respectable age of 22.
Jim Becker is the owner of Goodwin Creek Gardens.