Rue, or “Herb of Grace,” brings not beneficial insect predators to our gardens, but the great beauty of an active pollinator, the Giant Swallowtail Butterfly. This enormous butterfly, with wingspans that sometime achieve six inches in width, lays its eggs on the rue plant and when the larvae hatch, they disguise themselves as bird droppings and devour rue leaves at a rapid rate as they proceed to butterflyhood. Added to the blue-green leaves of the Rue, this butterfly is truly an amazing addition to the garden.
Easy-to-grow Rue, an ancient perennial herb, with liturgical connotations that cause it to be a standard plant for prayer gardens, usually goes dormant during the coldest months and then re-emerges in early Spring. It produces small but colorful yellow blooms — a lovely complement to the glaucous foliage.
Growers of rue should be cautious when working with it during the hot months — its sap, combined with the heat of a summer sun, can cause a skin rash in those sensitive to it. Most rue aficionados simply take the precaution of wearing a long-sleeved shirt when grooming the vigorously-growing plants.