Lavender is generally safe to eat.
However, it's important to use culinary lavender, which is typically English lavender (Lavandula angustifolia). Other varieties can taste bitter or soapy.
Use only the flowers (buds) and use them sparingly because the flavor is very strong.
Do NOT ingest lavender essential oil; it's highly concentrated and can be toxic.
If you're using lavender from your garden, make sure it hasn't been treated with pesticides.
Lavender can be used in teas, baked goods, syrups, and even savory dishes.