Butterflies are attracted to flowers, so attracting them to your garden means planting flowering plants. The first plant you would expect to find recommended is the butterfly bush (Buddleja davidii Franch.), but the Pennsylvania Department of Forestry asks that you avoid this plant. It is a non-native that becomes invasive in natural areas in many states, including Pennsylvania.
Here are alternative native plants that attract butterflies and need little or no maintenance. Native butterflies seek out the wildflowers that grow naturally where they live. Planting native flowering plants provides the right food and shelter for the butterflies that live nearby.
Butterflyweed (Asclepias tuberosa) is also called Orange Milkweed and Butterfly Milkweed although it does not have a milky sap. Butterflyweed has large clusters of orange flowers that attract butterflies and make a colorful addition to a garden. This plant is native to many areas of the US. Historically, Native Americans chewed the stems to relieve pulmonary problems. They called this plant Pleurisy Root.
Coastal Sweet Pepperbush
Sweet pepperbush (Clethra alnifolia) is a shrub native to many areas of the US. It is a deciduous shrub that has fragrant white flowers. The flower spikes attract butterflies. In the fall the leaves turn yellow and orange before they drop. The flowers are replaced by brown berries that stay on the branches through most of the winter. It is an attractive plant during most of the year.
Dense Blazing Star
Dense blazing star (Liatris spicata) is another native plant that attracts butterflies. This plant has purple flower spikes that resemble lavender. Dense blazing star is also called dense gayfeather and marsh blazing star.