The Facts Height: 2′ – 4′ Spread: 1.5′ – 3′ Sun: Full Sun Water: Medium Soil: Well-Drained Growth Rate: Fast Agastache, sometimes known as hyssop or hummingbird mint, is a native of the Midwest and Great Plains regions. Because of this, it thrives in Oklahoma’s climate. As a member of the mint family the foliage carries a slight fragrance to it. While there are many varieties and color of Agastache to choose from, most will grow to reach 2 – 4’ tall and spread 1.5 – 3’ wide.