(Editor's Note: This article was originally published on March 12, 2007. Your comments are welcome, but please be aware that authors of previously published articles may not be able to respond to your questions.)
The genus Lavandula is a favorite group of ornamental herbs native to southern Europe and the Mediterranean. These sun-loving plants thrive in hot weather and grow well in the West in a wide range of soils, even compost-enriched garden loams, as long as they are well drained. Heavy, poorly-drained clay soils can be fatal. Lavender plants will be taller and wider in mild winter, hot summer climates. The same varieties when grown in cold (zone 5-6) winter climates tend to be more compact. Lavender plants require two-to-three growing seasons to reach mature size.
Lavenders are rabbit and deer resistant.
Pruning established plants
In spring as needed. When plants begin to show signs of new growth, cut back the old stems by no more than a third to re-invigorate the plant and encourage more flowers. Harvesting the flowers each year helps maintain plant vigor.
Top-dress with Yum Yum Mix and Planters II once a year in mid-to-late fall or mid-spring (as the plants begin to show new growth).
Lavender must be planted in full-sun locations with good air circulation and fast-draining, alkaline soil. Sandy and sandy-loams are a “must” in the eastern US and Midwest! Lavender will tolerate clay and clay-loam in dry climates.
- Ample coarse-textured compost can be added at planting time to “open-up” heavier soils. Add lime in acidic soils. In wetter climates, plant on a slope or in raised bed to facilitate faster drainage.
- Two inches of very coarse sand or small diameter gravel around the base of the plant keep the crown drier and promotes healthy plants in all climates.
- Water deeply but infrequently after their 2nd growing season. Take care not to over-water established plants.
Cold-Hardy Lavender Varieties
English types: Lavandula angustifolia cultivars are among the most cold-hardy, and they bloom in late spring. They have compact flowering spikes on short-to-medium stems. ‘Hidcote Superior’, ‘Royal Velvet’ and ‘Mitcham Gray’ have the darkest flowers. ‘Graves’ is valued for its fragrant, long-stemmed flowers. ‘Buena Vista’ blooms twice, in spring and fall. Reports from the Denver area indicate that Lavandula angustifolia 'Nana' is an exceptionally cold hardy cultivar.
Lavandin (French hybrid) types: Lavandin or Lavandula x intermedia cultivars (hybrids between English lavender and L. latifolia) are among the tallest growers with elongated flowering spikes on long stems. ‘Provence’ and ‘Hidcote Giant’ are deliciously aromatic and are used for oil production and sachets. ‘Grosso’ is one of the best for use in crafts and as a dried flower.
Other hybrids: ‘Silver Frost’ has incredible silver foliage and a powerful fragrance. ‘English’ is compact and very fragrant. Both are exceptionally heat tolerant in low- humidity areas.
Culinary use: Lavandin has become popular as an herb for cooking. ‘Provence’ is an excellent variety for this use.