Can fresh basil stay in water?
If you mean as a way to keep it to use after you pick it, yes it will for a while but not indefinitely. A good way to store after picking is to take whole stems you have picked, wash them gently with cold water and then loosely wrap or roll them in a couple of paper towels. Put this in a plastic bag and place in the refrigerator. This will usually keep the basil very crisp and fresh for a week or a little longer.