Depends on how you store it. Lavender simple syrup is not like the store-bought stuff that lasts forever. It’s made with fresh or dried herbs and no preservatives, so it can go bad if you leave it out. The best way to keep your syrup fresh and tasty is to keep it in the fridge. It should last for about 2 weeks in a sealed jar or bottle. But if you want to make your syrup last longer, you can also freeze it! Just pour it into a freezer-safe container and pop it in the freezer for up to 3 months. When you need some syrup, just take it out and let it thaw in the fridge overnight. Then enjoy your delicious lavender simple syrup however you like!