Lavender (Lavandula) is a genus of perennial flowering plants native primarily to the Mediterranean region. It is renowned worldwide for its distinctive appearance and fragrant essential oils. This shrub is instantly recognizable by its cool-toned foliage and upright, colorful flower spikes, making it a stand-out plant in any landscape.
Overall Growth Habit and Size
Lavender is classified as a sub-shrub, meaning it has a woody base that persists year-round while the upper growth is softer. The plant typically forms a dense, bushy, and rounded mound, giving it a compact silhouette in the garden. This mounding habit keeps the foliage close to the ground before the flower stems emerge.
Mature plants of common varieties usually reach a height and width between one and three feet. Over time, the lower stems become hard and woody, which is a natural part of the plant’s structure. Annual pruning is necessary to maintain the attractive, bushy shape and prevent the plant from becoming overly woody or leggy.
Describing the Leaves and Stems
The lavender plant is characterized by its silvery-gray or grayish-green foliage. This muted color results from a dense covering of fine, star-shaped hairs, known as indumentum, which protect the plant from moisture loss. The leaves are typically narrow, linear, and elongated, often described as needle-like in common varieties.
Leaves are arranged oppositely along the stems, which are often four-angled, a characteristic of the mint family (Lamiaceae). New growth is softer and green, but the color quickly transitions to a woody brown at the base. The fine hairs give the foliage a soft, velvety texture when touched.
The Iconic Flower Structure
The most striking visual feature is the lavender inflorescence, a spike of flowers held high above the foliage on a long stalk. The flowers are clustered in whorls, or verticils, along the spike rather than blooming uniformly. Each whorl consists of a pair of condensed flower clusters, opening sequentially from the bottom toward the tip.
The individual flowers are small, bilaterally symmetrical, and generally come in shades of purple, blue-violet, or lilac. Pink and white varieties also exist. Each flower is protected by a tubular, ribbed calyx, which often remains on the stem after the petals have faded.
How Major Lavender Varieties Differ Visually
While the general form is similar, visual differences between major lavender species are distinct, particularly in the flowers. Lavandula angustifolia, or English lavender, features narrow, silvery leaves and dense, uniform flower spikes. The individual flowers are tightly packed, resembling a compact candle or bottle brush, with no large, petal-like structures at the tip.
French lavender (Lavandula dentata) is identified by its finely toothed, or “dentate,” edges, deviating from the smooth leaves of other types. Spanish lavender (Lavandula stoechas) is visually unique because its dense, pinecone-shaped flower heads are topped with prominent, colorful, petal-like bracts. These distinctive bracts, often described as “rabbit ears,” can be a different shade of purple or sometimes white.