Lavender is a popular herb with both scented and culinary qualities that grows in at least 30 different varieties. Of these, there are three main types: English, Spanish and French. The Spanish and French varieties are most often mistaken for one another, but you can identify them by their contrasting appearance, growth habits, bloom schedule, fragrance and uses.
Spanish lavender (Lavandula stoechas) is most obvious by its tight, deep purple, pinecone-shaped blooms. Four petals reach skyward, distinctly shaped like rabbit ears. Some varieties have white flowers. The bushes grow about 18 inches tall, with silvery-green leaves. French lavender (Lavandula dentata) sports looser-looking, light purple flowers. Their grayish leaves appear more serrated than those of their Spanish cousin.
Ironically, Spanish lavender thrives in France's warm, Mediterranean temperatures. French lavender likes cooler climates, and remains hardier year-round all the way to Zone 5. Like all lavender, both grow in compact bushes low to the ground and put out flowers on long, thin stems. They grow best in alkali soils.
The French variety blooms for the longest part of the year, earning it the nickname, "ever-blooming." Spanish lavender blooms from early spring until frost. Names of Spanish lavenders include Blue Star, James Compton, Otto Quasti, Helmsdale and White Spanish. French varieties usually have the Latin moniker "intermedia" in them, such as provence intermedia and alba intermedia.
Spanish lavender smells almost like a pine cleanser, sharper more than sweet, but refreshing nonetheless. French lavender takes on smoky hints, especially as it dries, and is more subtle than either the English or Spanish varieties.
While the other two aren't poisonous, it is the English variety of lavender that is most often used for culinary purposes, such as flavoring oils, butters and sugar, and in dishes. Some cooks, though, like a little French lavender for a change of pace, such as in herbs de provence. French lavender can substitute for rosemary in breads and other recipes. Spanish lavender, with the most compact heads and deepest hue, is the most often coveted for drying, both as flowers and in potpourri. Both scent a hot bath wonderfully if you soak them in the tub with you. Spanish lavender yields a strong essential oil.