"My first priority for my whole yard is reducing allergy pollen levels. My 2nd requirement for the front yard is that it either looks good all year round or it has low water requirements. My 2nd requirement for the back yard is that it either be edible or attract birds. Many plants meet multiple requirements. My most recent interest is insect gardening because most of my summer birds are insect eaters and I need pollinators and benificial insects for my fruits and veggies. "