Lavender (Lavandula angustifolia) is a semi-evergreen, perennial herb that belongs to the mint family. The herb is a common choice for culinary, ornamental and cutting gardens because the flowers are edible, highly fragrant and make a very beautiful display when planted en masse. Lavender is also widely used in cosmetics and perfumes, most notably in soaps and other bath products. How long it takes for lavender to reach maturity depends on the species or cultivar.
1. English Lavender
English lavender (Lavandula angustifolia) likely earned its common name because it performs well in that country’s climate, but the plant is not native to England. This is the “true” lavender that comes from the mountainous regions of the Mediterranean, and from which lavender essential oil is produced. English lavender requires full to partial sun and evenly moist but well-drained soil. This lavender species performs best in U.S. Department of Agriculture plant hardiness zones 5 through 8. If starting new plants from seed, it will take 90 to 200 days to reach maturity. English lavender is considered fully mature when it reaches between 1 and 2 feet in height with an equal spread.
2. Other Species
When shopping for lavender plants, you will quickly learn that the names for Spanish lavenders (Lavandula stoechas and Lavandula dentate) and French lavender (Lavandula dentata) are used interchangeably and inconsistently. In other words, if the tag doesn’t specifically read “English lavender,” it will be likely be generically referred to as either Spanish or French lavender. Knowing the plant’s point of origin is of little help because the herb commonly referred to as French lavender comes from Spain. Regardless, these plants have essentially the same culture and climate requirements as English lavender, reaching maturity when height measures about 2 feet. However, note that the plant hardiness zone for Lavendula dentata is 8 through 10b.
3. Dwarf Varieties
There are several compact cultivars of English lavender. “Hidcote” (Lavandula angustifolia "Hidcote") and "Munstead" (Lavandula angustifolia "Munstead") are both suitable for container gardening, maturing to a height of 1 to 1.5 feet. Although they are slightly smaller than standard lavenders, within 2 or 3 years they should be transferred to a garden spot in USDA zone 8. The dwarf cultivars “Nana Alba” (Lavandula angustifolia “Nana Alba,” and “Irene Doyle” (Lavandula angustifolia “Irene Doyle”) are content to remain in containers.
Lavender hybrids are a cross between English lavender and spike lavender (Lavandula latifolia) and are collectively called lavandins. They share similar characteristics with English lavender in that they mature when stems reach between 18 and 24 inches long and they yield a high-quality essential oil suitable for use in cosmetics and aromatherapy. Although they also perform well in USDA zones 8 and 9, they bloom later in the season, from mid- July through late August.