To keep herbs with long stems for at least a week, if not longer. 

Wash and dry them thoroughly. 

Trim the stem ends. 

You want to place the herbs in a tall, airtight container with a tight-fitting lid. 

Add water up to the top of the stems, but don’t cover the leaves. 

Seal the container securely and refrigerate. 

The combination of water and little air keeps them fresher than other technique.