Focus on flora: Giant milkweed

plant with green leaves and lavender flowers

If you’ve ever tried planting a butterfly garden, you would most certainly be familiar with giant milkweed, or Calotropis gigantea. When attracting colourful butterflies — monarchs in this case — to flit through the garden, it is important to remember that they are not only interested in nectar from flowers, but to larval plants as well. In fact, a giant milkweed can host both larvae and adults of the monarch butterfly, and in some cases, the caterpillars will pupate on the plant itself.

Native to parts of Southeast Asia, and tropical Africa, the giant milkweed grows best in tropical or subtropical climates as a perennial. This evergreen shrub needs plenty of space due to its sprawling, unusual growth habit. It can grow up to 15 feet in height and reach a similar spread. Like most plant material in Cayman, it prefers well-draining soils and will tolerate periods of drought, though salt tolerance is marginal.

Situated in full sun or part shade, giant milkweed is a low maintenance shrub that will require infrequent pruning, unless the preference is to keep it short and stout, in which case it will still flower. The leaves are wide and stiff, providing the caterpillars plenty of surface area and stability for munching. Adding to the support for these cheerful little tricoloured critters, the leaves are pubescent, which means covered in fine, small hairs.

The silver colouring on the leaf provides a cooler surface and is a pleasing complement to the lavender- or white-coloured flowers. The flower itself has five waxy petals and a "crown" that emerges from the center, giving it its other common name — crown flower.

Blooming all year round, giant milkweed can also provide excellent educational opportunities and fun science experiments for children and adults alike. Whether it's enjoying the soft silvery texture of the thick leaves, the waxy appearance of the crowns and flowers, the white, yellow and black caterpillars, or the majestically transformed orange, black and white monarch butterflies, there are many reasons to add this gem to any landscape.

In Camana Bay, the giant milkweed can be found at the base of the bridge to the Festival Green.

This article originally appeared in the August 2021 print edition of Camana Bay Times.

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About the author

Shannon Schmidt is a horticulture manager at Dart’s Arboretum Services Ltd. Joining Dart in 2012, Shannon previously worked in parks, public gardens and tourism properties, among others. Originally from the Finger Lakes region of New York State, Shannon loves island life, spending time paddleboarding around the canals and mangroves, in the sea, and spending time outdoors with her two energetic Boston Terriers Nollie and Ebbie and her equally energetic partner Chase! Shannon holds a Bachelor of Science in Recreation, Park and Tourism Management from The Pennsylvania State University and a Diploma in Horticulture from the Longwood Gardens Professional School of Horticulture, and loves spending time swinging in a hammock, with her favourite smoothie from Jessie’s Juice Bar and reading material from Books & Books.

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