Rue (Ruta graveolens) is a charming perennial with aromatic, fern-like leaves and clusters of yellow flowers. Evergreen foliage takes on blue-green hues and releases a sweet and spicy fragrance when touched. Though it blooms with small yellow flowers in early summer, Rue is valued for its foliage. It serves as a host plant for swallowtail butterflies, including the black swallowtail, giant swallowtail, and anise swallowtail. You can find adult butterflies laying eggs on the leaves, then enjoy watching the caterpillars grow through the season. It may not be as showy as other pollinator plants, but it s just as important to include it in your garden!