Lavender
Where and how you plant is all important. Keep in mind that the lavenders are native to the Mediterranean, and if you've ever been to the South of France, you know that means hot, rocky, and arid--almost desert-like in many places. This tells you lavenders demand sharp-draining soils, never rich, damp and soggy. In fact, if your soil is heavy, it's worth it to mix in some sand or gravel before you plant, and perhaps create little mounds for your plants so each one drains quickly. Fact is, if you fail with lavender, it will probably be due to over-watering. Lavenders don't mind drought a bit, and love hot, blazing sun. Remember, little water and no shade!