Antelope Horn Milkweed

Asclepias asperula

Milkweed, Antelope Horn, Spider Milkweed, Green-flowered Milkweed

About This Plant

Sun or partial sun. A clump-forming deciduous perennial, up to 24 inches. Big flowerheads appear throughout the warm season, followed by green seed follicles that curve as they lengthen hence the common name: antelope horns. The thick leaves are long, narrow and folded lengthwise, somewhat resembling their close relative, tropical milkweed. A roadside weed in the Blackland Prairie and Edwards Plateau, this species is becoming harder to find due to local development and roadside mowing. Milkweeds are the only food source for monarch butterfly caterpillars. Although robust, antelope horn is difficult to propagate in a greenhouse setting, so it’s uncommon at commercial nurseries; preserve it if you have it on-site.

Origins: Western U.S., northern Mexico


None required, beyond the care needed to establish it in its preferred setting — weedy roadsides and inferno strips. Aphids are likely to infest any milkweed, but they aren’t really a problem. They can be sprayed off with soapy water. Treating aphids will (obviously) wipe out the monarch caterpillars too.

The go-to native milkweed for attracting monarch butterflies.

Min. Height: 6'

Max Height: 12 inches'

Min. Width: 1'

Max Width: 3 feet'

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