Most lavender flowers bloom in the summer, especially in the month of June. However, the specific months depend on the variety of lavender as well as the weather conditions in the place they are planted.
English lavender varieties grow in the late spring and early summer, from about late May to early July. In many places around the globe, these are the most common varieties of lavender. There are also earlier-blooming lavender flowers (such as sweet lavender or Spanish lavender) that do well in warmer climates.
The most famous type of lavender, however, is the hybrid lavender (or "lavandin") grown in the Provence region of France. This lavender blooms from June throughout August, with the traditional lavender harvest season starting in mid-July. Provence lavender is darker, taller and more aromatic than other varieties and is the lavender most commonly used for cooking as well as in the perfume industry.