Western Tiger Swallowtail, its range covering much of the western United States, will visit gardens and nectar on garden plants. It usually flies high off the ground but will swoop down to nectar and check out the neighborhood. If the garden conditions are favorable, it will choose your garden to form a brood. We have seen it nectaring on Verbena bonariensis, even with other flowering plants nearby. There is an affinity between them.

Western Tiger Swallowtail (Papilio rutulus) are known to use various trees as a host plant for laying their eggs. We have seen the caterpillar of this species nibbling on Fennel (Foeniculum vulgare) and so have let this plant blossom and go to seed, converting parts of the vegetable garden into butterfly habitat. Fennel contributes to their life-cycle when growing in the vicinity of a host plant. Both Foeniculum vulgare and Verbena bonariensis can be grown in containers.

According to the butterflies and moths web site, Populus, Salix, Prunus and Fraxinus trees serve as host plants for this butterfly.

Western Tiger Swallowtail is a stunning fairly large butterfly that can be twice the size of other butterflies visiting your garden. It is a pale yellow shade overall with distinct black "swallowtail" markings and has a long tail extending from the lower hind wing.