Agastache is a perennial plant with lovely flower spires that bloom all season long. The Agastache flower is commonly found in purple to lavender, but may also bloom in pink, rose, blue, white, and orange. Growing Agastache as a drought-loving perennial actually produces the best plants. An Agastache plant is tolerant of low water and poor nutrient conditions, but provides you with a color display and enduring greenery for months. Learning how to grow Agastache requires no special skills or care.