Antelope Horns: The Essential Milkweed for Monarchs!

Antelope Horn Milkweed

Wildflower season is upon us in Central Texas, and among the many captivating flowers, the Antelope Horn milkweed plant (Asclepias asperula) stands out as both intriguing and vital. Also known as spider milkweed or green-flowered milkweed, this unique plant features clusters of small green and white flowers that resemble large green balls from a distance. Growing up to two feet tall, these plants have long, narrow leaves that are often folded lengthwise. However, the most distinctive feature of Antelope Horn milkweed is its seedpods, which, when mature, curve and point like the horns of an antelope.

Beyond its aesthetic appeal, Antelope Horn milkweed plays a crucial role in supporting the survival of monarch and queen butterflies. Central Texas serves as the first stop for Monarch butterflies during their long migration north. Milkweeds are essential because Monarch Butterfly caterpillars exclusively rely on them for sustenance. After forming chrysalises, the new Monarchs continue their journey north, ready to lay the next set of eggs and rear caterpillars. Additionally, the nectar produced by Antelope Horn milkweed flowers is rich in glucose, benefiting various other species, including native bees and honeybees.

As our landscape transforms due to development, the significance of planting milkweeds in gardens becomes even more pronounced. You can grow Antelope Horn milkweed from seeds or propagate it through root cuttings. Root cuttings are best done in the fall or early spring, while seeds should be planted either in late fall or early spring. You can collect seeds in June from established plants or order them online. Preparing the seeds for germination requires soaking them in water overnight, while cold moist stratification involves chilling the seeds at 40 degrees Fahrenheit for up to three months. Planting in late fall naturally exposes the seeds to the required moist and cold conditions. For optimal germination, choose the warmer months of the year.

Antelope Horn milkweed thrives even in dry years thanks to its robust tap roots. It prefers well-drained soil and full sun. If you’re cultivating Antelope Horn as a garden plant, consider trimming it back selectively to provide fresh leaves for caterpillars throughout the summer.

While this milkweed variety greatly benefits butterflies and pollinators, it does contain cardiac glycosides, imparting some toxicity. Deer and livestock instinctively avoid it due to its unpleasant taste. Although these toxins do not harm Monarch butterflies, they make them unpalatable and potentially poisonous to predators. It’s worth noting that tropical milkweeds lack these toxins, leaving Monarch caterpillars vulnerable to predators. In humans, the sap can cause skin irritation. Sensitivity varies based on age, weight, and individual predisposition. Children are particularly vulnerable due to their curiosity and smaller size, which can magnify the effects of even a small dose of toxin. However, it’s important to recognize that Antelope Horn milkweed also possesses beneficial medicinal properties. For instance, the toxic cardiac glycosides it contains resemble digitalins, which are used in treating heart disease. Native Americans brewed tea from this plant, using it as a tonic to strengthen the heart, while the Navahos relied on it to treat bites from rabid animals.

Antelope Horn milkweed is not the only variety that supports the survival of Monarch butterflies. Green Milkweed, Butterfly Weed, Common Milkweed, Showy Milkweed, and Swamp Milkweed are other native species that can be planted in landscapes to provide essential sustenance for these majestic creatures.

So, if you’re looking to make a positive impact on your environment and contribute to the conservation of Monarch butterflies, consider adding Antelope Horn milkweed to your garden. Give these stunning plants the space they need to grow, and witness the captivating journey of caterpillars transforming into beautiful butterflies right before your eyes.