Lavender, the fragrant perennial herb prized for its calming scent and purple blooms, is not native to Pennsylvania. This member of the mint family, Lamiaceae, is a non-native species successfully adapted for cultivation across the state. While it thrives in many Pennsylvania gardens, its environmental needs differ from the local climate, requiring gardeners to implement particular growing techniques.
Lavender’s True Origins
The natural home of the Lavandula genus is centered in the Old World, primarily distributed across the Mediterranean Basin. This includes Southern Europe, North Africa, the Arabian Peninsula, and parts of the Middle East. The original habitat is characterized by hot, arid summers and mild winters.
These conditions led to the plant’s preference for dry, rocky, or sandy soils low in organic matter. The plant’s silvery foliage is an adaptation to reflect intense sunlight and minimize water loss. Understanding this native environment is the foundation for successfully growing lavender in climates that do not mimic these conditions.
Growing Lavender Successfully in Pennsylvania
Cultivating lavender successfully in Pennsylvania requires mitigating the differences between the Mediterranean climate and the state’s typical environment, which involves cold, wet winters and dense, clay-heavy soil. The most significant threat to lavender in this region is excessive moisture, particularly during the dormant season. Root rot is the primary cause of plant failure when the soil remains consistently wet.
To counteract this, gardeners must prioritize creating excellent drainage, as lavender cannot survive in soggy conditions. Incorporating grit, coarse sand, or fine gravel into the planting area is necessary to improve the soil structure. Many growers opt for raised beds or planting on slopes, which prevent water from settling around the plant’s crown. Lavender prefers a slightly alkaline soil with a pH around 7.0, so a soil test may indicate the need for garden lime.
Lavender requires a minimum of six to eight hours of direct sun daily to maintain dense growth and maximize flower production. Once established, the plants are drought-tolerant and should be watered sparingly, allowing the soil to dry completely between waterings. Pruning should be performed annually to encourage air circulation and prevent the plant from becoming woody at the base. Avoid cutting back plants in the fall, as this can expose the crown to winter moisture and cold damage. Instead, prune lightly after the first bloom or wait until new green shoots appear in the spring.
Recommended Varieties for Cold Climates
For gardeners in Pennsylvania, which falls mainly within USDA Hardiness Zones 5 through 7, selecting the right variety is key. The most cold-hardy group is English Lavender, Lavandula angustifolia, which can survive the winter when given proper drainage. Popular cultivars include ‘Munstead’ and ‘Hidcote.’ ‘Munstead’ is noted for its tolerance of summer heat and humidity, which is beneficial in the mid-Atlantic climate.
Another excellent choice is the hybrid known as Lavandin, or Lavandula x intermedia, which results from a cross between English and Portuguese lavender. These hybrids, such as ‘Grosso’ and ‘Phenomenal,’ are known for their vigorous growth and are more tolerant of the higher humidity found in Pennsylvania than pure English varieties. The cultivar ‘Phenomenal’ is recognized for its cold tolerance down to Zone 5 and its resistance to foliar diseases. Less hardy types, such as French lavender (Lavandula dentata) or Spanish lavender (Lavandula stoechas), are not suited for overwintering in Pennsylvania and are best treated as annuals or container plants brought indoors for the winter.