Larvae feed exclusively on milkweeds (Asclepias spp.); butterfly weed is one of the most-recommended host plants for monarch garden plantings because of its showy orange flowers and drought tolerance.

Larvae feed exclusively on milkweeds (Asclepias spp.); A. syriaca is one of the principal monarch host plants across eastern North America. The single most wedge-load-bearing wildlife relationship in the catalog.

Asclepias incarnata is among the canonical monarch larval host plants — same status as A. syriaca but in a wet-meadow rather than disturbed-roadside ecological context. Caterpillars sequester the cardiac glycosides from the milkweed sap as predator-deterrent defense. Planting swamp milkweed is the wet-site equivalent of the common-milkweed conservation action.

Both the Missouri Botanical Garden PlantFinder ("attractive to butterflies throughout the growing season") and NC State Extension document butterfly nectar value; the late September-October bloom overlaps the southbound monarch migration.

Late-summer nectar for migrating butterflies; the Missouri Botanical Garden PlantFinder lists boneset as attracting butterflies, though it names no specific species, so the monarch association is inferred from the documented butterfly-nectar value rather than a species-level citation.

Zinnias are a well-documented nectar source for butterflies; Missouri Botanical Garden PlantFinder lists Zinnia elegans as attracting butterflies, and the flat, open, late-season flower heads are a favored monarch nectar plant.

Liatris spicata is among the most-cited monarch nectar plants in the eastern flora — the dense purple spike's late-summer bloom timing aligns precisely with the eastern monarch migration south to Mexico. Planting Liatris is the canonical complement to milkweed (host) for full-life-cycle monarch support.

Late-season nectar fuel for migrating monarchs heading toward Mexican overwintering grounds.

The Missouri Botanical Garden PlantFinder records Shasta daisy as attractive to butterflies; the flat, open flower heads are an accessible nectar platform for butterflies during the midsummer-to-fall bloom.

Missouri Botanical Garden PlantFinder records the flowers as attractive to butterflies; mountain mint is a frequently observed late-summer nectar plant for migrating and breeding butterflies.

Late-season bloom timing makes swamp sunflower a critical fall-migration monarch nectar source.

Joe-Pye weed is a canonical late-summer nectar source for monarchs preparing for fall migration. NC State lists "butterflies, skippers, moths, and bees" among the flower visitors; the monarch relationship is heavily documented in pollinator ecology literature.