How do I identify different lavender varieties outdoors?

Identifying different lavender varieties grown outdoors involves observing a combination of their physical characteristics, growth habits, and scent profiles. While there are many cultivars, they generally fall into a few main species or hybrid groups, each with distinct features that help in identification.

Here's how to identify different lavender varieties outdoors:

1. Start with the Main Species/Hybrid Groups: Understanding the primary botanical classifications is the most effective way to begin identification.

• English Lavender (Lavandula angustifolia):

  • Foliage: Leaves are typically narrow, relatively long (around 2-3 inches), and have smooth, untoothed edges. They are usually grayish-green, sometimes with a silvery cast, and form a dense mound.

  • Flowers: Flower spikes are generally short and plump, appearing on relatively short stems (often not much taller than the foliage itself). The individual florets are densely packed on the spike. Key identifying feature: there are no large, petal-like "bunny ear" bracts on top of the flower head. Colors range from deep violet to blue-purple, pink, and white.

  • Fragrance: Renowned for its sweet, delicate, purely floral, and subtle herbaceous aroma. This is the classic, gentle "true lavender" scent, with very low or no camphor notes.

  • Growth Habit: Forms a neat, compact, mounding shrub, typically 1.5 to 2.5 feet tall and wide.

  • Bloom Time: Generally blooms in late spring to early summer, often with a smaller second flush later in the season if deadheaded.

  • Hardiness: Excellent cold hardiness (typically USDA Zones 5-9, sometimes 4 with protection).

• Lavandin (Lavandula x intermedia):

  • Foliage: Leaves are generally broader and grayer than English lavender, and can sometimes have a slightly toothed or serrated edge, though less pronounced than French lavender. The foliage itself can appear more robust.

  • Flowers: A key identifier for lavandins is their flower spikes. They are long, slender, and borne on very long, sturdy stems that rise significantly above the foliage. The individual florets are usually more spaced out along the stem compared to English lavender. No prominent "bunny ear" bracts.

  • Fragrance: Possesses a stronger, more pungent, often camphoraceous or herbaceous scent, a blend between the sweet notes of English lavender and the sharper notes of spike lavender.

  • Growth Habit: These are much larger plants, forming substantial, robust mounds, typically 2.5 to 4 feet tall and wide (or more). They create a significant presence in the landscape.

  • Bloom Time: Usually blooms later than English lavender, typically from mid-summer into late summer, providing a valuable late-season bloom.

  • Hardiness: Good heat and drought tolerance, typically hardy in USDA Zones 5-9.

• Spanish Lavender (Lavandula stoechas):

  • Foliage: Leaves are generally shorter, narrower, and often more grayish-green than English or French lavender, and may have finely serrated edges that are subtle.

  • Flowers: This is the easiest lavender to identify due to its unique flower heads. They are compact, pinecone-shaped, and distinctively topped with prominent, colorful petal-like bracts that resemble "bunny ears" or "flags." These bracts can be purple, pink, or white, and are often showier than the actual flowers.

  • Fragrance: The flowers typically have a stronger, more resinous, or camphoraceous scent, often described as eucalyptus-like, which is quite different from the sweet scent of English lavender. The foliage is also quite aromatic.

  • Growth Habit: Tends to form a more upright, somewhat looser shrub, typically 1 to 2.5 feet tall and wide.

  • Bloom Time: Often blooms earlier than English lavender, typically in mid to late spring, and can have a very long bloom period with repeat flushes throughout summer and into fall in warm climates.

  • Hardiness: Less cold-hardy, generally suited for USDA Zones 7-10, but more tolerant of heat and humidity.

• French Lavender (Lavandula dentata):

  • Foliage: The most distinguishing feature of French lavender is its leaves: they are visibly toothed or serrated along the edges (hence "dentata," meaning "toothed"). They are typically green to grayish-green and often longer than Spanish lavender leaves.

  • Flowers: The flower spikes are slender and generally topped with small, delicate, somewhat wispy bracts. These bracts are present but are not as large or prominent as the "bunny ears" of Spanish lavender. The individual flowers are usually violet or purple.

  • Fragrance: The entire plant (foliage and flowers) has a strong, herbaceous, slightly rosemary-like or camphoraceous scent, less sweet and more pungent than English lavender.

  • Growth Habit: Tends to be a larger, more sprawling, or shrubby plant, typically 2 to 3 feet tall and wide, forming a looser mound.

  • Bloom Time: Known for its exceptionally long blooming season, often flowering almost continuously from spring through fall in warm, frost-free climates.

  • Hardiness: Generally suited for USDA Zones 8-10, tolerates heat and humidity well.

2. Practical Identification Steps Outdoors:

• The Scent Test: Gently rub a leaf or a flower spike. The aroma is a strong clue: sweet (English), camphoraceous/eucalyptus (Spanish), herbaceous/rosemary (French), or pungent/camphoraceous (Lavandin).

• Examine the Flowers:

  • Are there prominent "bunny ears" on top of the flower heads? If yes, it's Spanish lavender.

  • Are the flower spikes short and plump on short stems? Likely English lavender.

  • Are the flower spikes long and slender on long, robust stems? Likely a Lavandin.

  • Are the flower spikes slender with small, wispy bracts, and do the leaves have teeth? Likely French lavender.

• Look at the Foliage: Check the leaf edges for teeth. Observe the color (silvery vs. greener) and overall density.

• Assess Overall Size and Growth Habit: Is it a small, neat mound? A large, imposing shrub? A looser, sprawling plant?

• Consider Bloom Time: Knowing when it blooms in your area can help narrow down the possibilities.

By systematically observing these characteristics, you can effectively identify the different lavender varieties flourishing in outdoor settings.