Herb to Know: Lavender 'Grosso' Plant

Enlarge Image Image Gallery With 'Grosso', you can realize the dream of beautiful lavender in your garden. Photo by Rob Cardillo

With its brisk aroma and eye-catching flowers, lavender has become a symbol of the delicious life. To many Americans, lavender evokes a mythical Provençal night: the window open to the warm night air, a view of faraway hills, clean linen, crusty baguettes, a bottle of wine, and someone to love. Unfortunately, for those of us in much of the continental United States, a healthy lavender plant sometimes remains as elusive as the dream of a Mediterranean paradise.

Lavender 'Grosso' Plant• Lavandin
• Lavandula ×intermedia ‘Grosso’
• Hybrid of cold-hardy English (Lavandula angustifolia) and heat-tolerant Portuguese lavenders (L. latifolia)
• Zones 5 to 9

For years, English lavenders (varieties of Lavandula angustifolia) were promoted as the most adaptable because of their cold-hardiness. However, they tend to melt in the humidity and heat of summer.  Lavandins, L. ×intermedia hybrids, combine the cold-hardiness of English lavender with the greater heat tolerance of a Portuguese lavender species, L. ×latifolia. The resulting hybrids are adaptable, heavy-flowering garden plants with a strong scent.

Of the lavandins, the best for all-round garden performance is the variety ‘Grosso’. ‘Grosso’ is the primary commercial variety for production of lavender oil. Its deep aroma, large flower heads, and heavy-flowering nature make it highly profitable to grow. Fortunately for gardeners, it makes an excellent garden plant that is highly adapted throughout the United States.

With some of the most richly colored flowers of all lavandins, ‘Grosso’ makes an impressive show in the garden. Its flowers are a strong violet-blue that shimmer in the summer sunlight. It has a more elegant habit than English lavenders, with long, graceful flower wands making a vast lilac halo around the central mound of silver foliage. It’s heavy-flowering, with sporadic repeat bloom after the main flush of flower in midsummer.

When not in bloom, plants of ‘Grosso’ make compact mounds of silver foliage to 3 feet high and wide. In winter, the foliage picks up tones of pink, violet and blue. With its strong globe shape, ‘Grosso’ is particularly attractive for geometric plantings. A grid of lavandin in gravel would be an excellent low-maintenance substitute for a lawn. ‘Grosso’ grows well in rocky or sandy places. It makes an excellent low hedge and its tolerance for hot, dry conditions lets it thrive along the edges of masonry walks and walls.