One of the best ways to prevent a loss of plants during the drought season is to plant for it, after all - If you cant beat 'em, join 'em. Drought tolerant plants are a easy way to prevent loss of plants in a dry season and can range from the soft and fluffy (lambs ear) to the smooth and waxy (stone crop). The Ecchinecia plant is known for it's drought resistance, same with the Black eyed susan.
whatever you try, make sure you read the labels and always plant for your zones and sun types.