Because of our heavy, clay-based soils and humid summers, lavender can be a difficult plant to grow in Western Pennsylvania. But, it doesn't have to be.
Hardy to about -20 degrees, lavender is a native of the Mediterranean region. It requires good drainage and full sun, and if you want the best chances of success, you'd be wise to begin your journey by selecting the right variety.
For years, English lavender (Lavandula angustifolia) was the principal lavender most gardeners tried to grow. With many cultivars available, English lavender blooms in late spring and early summer, and is a great addition to the herb or perennial garden. Fragrant purple flower spikes arise from the gray foliage. The main downfall of this species is that it doesn't perform well in high humidity.
Popular English lavender varieties include “Munstead,” which is touted as being among the most heat-tolerant of the English types; “Hidcote,” which prefers cooler weather; “Jean Davis,” which produces lovely pink flowers but can be a challenge to grow; and “Royal Purple,” which produces flowers that are excellent for drying and hold their color quite well.
If you've struggled to grow English lavender, I suggest you turn your efforts to growing hybrid lavender instead. Commonly called lavandin, this type of lavender is likely the best for our climate. Lavandin cultivars are heat- and drought-tolerant, very floriferous and highly fragrant.
The Latin name for this hybrid is Lavandula x intermedia, and it was bred by crossing Lavandula angustifolia with Lavandula latifolia to create a new species.
The gray leaves of this species are longer, and the plants generally grow much faster than English lavenders. They bloom a few weeks later than their English cousins, too. They aren't as fussy about drainage, though they still perform best in well-drained, full-sun areas.
My favorite hybrid lavender varieties are “Grosso” for its highly fragrant, lovely, dark purple flowers (fields of “Grosso” lavender are common in France); “Dutch Mill” for its light purple flowers; “Provence” for its light blue flowers and high essential oil content; and “Grappenhall” for its slender flower stalks and quick growth rate.
To grow lavender, give the plants plenty of room; space them 3 to 4 feet apart. And to maintain proper growth and blooming habits, prune the plants immediately after flowering by removing the spent flower stalks and one-third of the foliage.
English lavender is notoriously difficult to grow from seed, as germination rates are low and often the seeds rot before they can sprout. And it's impossible to grow many of the L. x intermedia cultivars from seed because most of these varieties produce sterile seeds. Instead, lavender is best propagated by taking cuttings.
Many local nurseries sell lavender, along with other herbs, so it's not difficult to find locally. However, it's worth taking the time to seek out the best variety for your growing conditions before planting. Ask your favorite local nursery what species and varieties they can provide.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden: A Natural Approach to Pest Control.” Her website is jessicawalliser.com.
Send your gardening or landscaping questions to tribliving@tribweb.com or The Good Earth, 503 Martindale St., 3rd Floor, D.L. Clark Building, Pittsburgh, PA 15212.
