Maybe I'm alone here, but I get really enamored with plants at the nursery and sometimes forget to do my homework. In this case, I saw a tag that said "French Lavender" and assumed my garden would smell like Provence. Uh, not quite.
Let's start out by saying, one thing all lavender loves is a sunny, open spot with well-draining soil. These plants are drought tolerant and pest resistant. If you have very clay soil, amending it with some sand and mulch will help immensely with drainage and keep your lavender plants happy.
The lavender I planted (pictured above) is French lavender (L. dententa) and is known for its showy foliage and purple blooms, but isn't particularly fragrant. It has a very clean, green scent to it, but certainly not the scent we have come to associate with the name. It can grow to nearly 3 feet in height and is mostly planted for decorative purposes. I tend to have trouble slowing down, so I thought that growing lavender to cut and bring indoors would be a good way to encourage relaxation. Obviously I was pretty bummed out when I realized I had planted the wrong variety.
English lavender is what we most commonly associate with the lavender fragrance and for culinary purposes. It can grow 2 to 3 feet in height and commonly has medium purple flowers (though some varieties have pink, white or blue flowers). If you're planning on using your lavender for cooking or craft projects, the English varieties are the way to go.
Spanish lavender has deep purple pinecone-shaped flowers and silver grey foliage. They're great for more humid climates and have a piney, clean fragrance...but not quite the typical scent we associate with lavender. They are often confused with French lavender, but these blooms are more intensely colored. They grow 1 1/2 - 2 feet tall and require pruning after the flowers fade.
For the sweetest of all the English lavenders, Martha Stewart recommends Hidcote lavender. Two more fragrant varieties are Provence lavender (Lavandula x intermedia 'Provence'), which despite its name, hails from Canada and Grosso lavender (Lavandula x intermedia 'Grosso').
Be sure to check what will work best in your hardiness zone, but this should be a good primer so you don't repeat my mistake!
(Image: Michelle Chin)