Lavender, admired for its distinctive fragrance and beautiful purple spikes, is a Mediterranean herb often sought after by gardeners in cooler climates. The question of whether this plant can survive year after year in cold regions, such as USDA Zone 5, is common. The answer is conditionally yes, as certain hardy types of lavender can indeed behave as perennials in Zone 5, but success is highly dependent on selecting the correct variety and providing specific winter protection.
Defining Perennial Status in USDA Zone 5
A perennial plant is defined as one that lives for more than two years, returning each spring from the same root system. The ability of lavender to achieve this perennial status is tested by the minimum winter temperatures of its environment. The USDA Plant Hardiness Zone Map is the standard tool for determining a plant’s cold tolerance.
USDA Hardiness Zone 5 is characterized by average annual minimum temperatures that fall between -20°F and -10°F (-28.9°C and -23.3°C). This temperature threshold is a significant challenge for the entire Lavandula genus, as it originated in the milder Mediterranean regions. While many common lavender types cannot endure this cold, a few select varieties have developed the necessary hardiness to survive this range.
Hardy Lavender Varieties for Cold Climates
The most reliable lavender for cold climates belongs to the English lavender species, Lavandula angustifolia, which is the most frost-tolerant type. Despite its name, this species originated in the mountains of the Mediterranean and can withstand temperatures as low as -20°F. Gardeners in Zone 5 should focus their selection exclusively on cultivars of English lavender.
Two of the most dependable cultivars for Zone 5 are ‘Munstead’ and ‘Hidcote’, both known for their superior cold tolerance and resilience. ‘Munstead’ is often cited as the most cold-hardy, known for its pale purple flowers and strong aroma, surviving well into Zone 3 with proper care. ‘Hidcote’ is also very cold-hardy, producing darker purple flowers on straight stems, making it excellent for cutting and drying.
Another strong option is the hybrid ‘Phenomenal’, a cross between English and Portuguese lavender, known as a lavandin (Lavandula x intermedia). This newer hybrid is hardy from Zone 5 to 8, noted for its disease resistance and ability to tolerate both cold and humidity. Conversely, French lavender (Lavandula stoechas and L. dentata) are significantly less hardy, surviving only in Zone 8 and warmer, and should be avoided for in-ground planting in Zone 5.
Essential Winter Care for Survival
Successful overwintering in Zone 5 requires specific environmental modifications, even for the hardiest English lavender varieties. The single most important factor for lavender survival is excellent soil drainage, as the roots are highly susceptible to rot, particularly when dormant in cold, wet soil. To ensure adequate drainage, gardeners often amend heavy soil with materials like coarse sand or gravel before planting.
The planting location should also provide maximum sun exposure and shelter from harsh winter winds, which can desiccate the evergreen foliage. Fall pruning should be avoided as heavy cutting can stimulate new, tender growth that is easily killed by the first hard frost. Instead, wait until spring to prune, once new growth has begun, allowing the old foliage to help insulate the plant.
A light layer of insulating material, such as straw or evergreen boughs, can be applied after the ground freezes to protect the root crown from freeze-thaw cycles. This mulch should be loose to prevent moisture accumulation, which could lead to crown rot. The cold signals the plant to enter its necessary dormancy phase, which protects it from the worst of the winter temperatures.