Pour the pureed nectarine and strawberry juice through a mesh strainer to remove any chunks of fruit.
Pour water in a large pitcher and add nectarine and strawberry juices while adding lemon juice.
Stir well to blend, add agave, and stir well again.
Put ice in each glass, pour the nectarine lemonade with strawberries into the glass, and add a fresh strawberry in the glass or on the edge of the glass.