Calotropis Procera- Giant Milkweed Tree Monarch Caterpillars

A Milkweed Tree To Feed Them All

Calotropis procera: Rooster tree, Sodom apple, Rubber bush, Swallow-wort, Milkweed tree

Double Duty Milkweed Plant- Calotropis procera is a milkweed tree that is both a host plant and nectar flower for monarchs, as you can tell from this evidence in this picture... — For Caterpillar…and Butterfly!

Plant Specs:

Perennial: USDA hardiness zones 9a-11 (lows -6.7 °C or 20 °F)
Annual in colder zones
Full sun to part shade
Height: up to 15 feet
Spacing: at least 6 feet, 15′ for perennials
Flowers: maroon, purple, white
Velvety silvery-gray leaves
Blooms all season

Monarch Caterpillars love dining on the thick leaves of Calotropis procera, but the showy flowers bloom all season long and provide nectar to monarchs, hummingbirds, and more... — Dining Room Centerpiece

Pros:

Constant blooms provide monarchs an all season nectar source
Large, thick leaves can sustain more caterpillars
Caterpillars don’t need to crawl away to pupate
Great option for adventurous gardeners looking to try something new
Fragrant flowers (unlike its wider known relative Calotropis gigantea)

A monarch caterpillar can safely form its chrysalis on the thick branches of rooster tree milkweed. — Milkweed Tree Convenience

Cons:

Slow growth for annual zones. Faster growing Calotropis gigantea is a better option
Not enough data from North America – needs to be monitored for potential problems
Prone to aphids like most species…again, keep an eye on your plants.
Has been reported to be invasive in India and Africa
It’s non-native so also plant native milkweed varieties to support your local ecosystem (Monarchs will use both native and non-native varieties)

Calotropis procera is a lesser known milkweed that supports monarch butterflies all season long with its beautiful multi-colored blooms. — Beautiful Bouquet of Milkweed

Plant Propagation Options:

Start seeds indoors 2 months before final frost
Seed Starting- use peat moss mix with vermiculite, perlite, or both
Soak seeds in warm water 24 hours before planting
Use a seedling heat mat for faster germination
Spring Sow directly after final frost
Propagate from softwood stem cuttings. This also allows you to start the season with larger plants. Our plants did not flower in year 1 starting seeds.

Calotropis procera serves two purposes in your butterfly garden. It's a host milkweed plant for monarch caterpillars, and nectar flower for butterflies and other beneficial pollinators. — Starting to Seed | © Forest and Kim Starr

Calotropis Procera Growing Tips:

Container garden option
Do not overwater- C. procera does not like having wet feet
Overwinter in pots for annual zones.

Overwintering Calotropis Procera Indoors- have sufficient drainage from your container and keep the soil for this milkweed variety on the dry side.

After a couple months of hot summer sun and some slow release fertilizer:

Calotropis procera- this tropical milkweed variety grows well in containers with lots of sun, good drainage, and some slow release fertilizer. — Calotropis in Containers

If you don’t want new seedlings next spring, simply cut off the seed pods before they pop open or tie organza bags over them to collect milkweed tree seeds. Seeding is not an issue for annual zones.

Open Milkweed Pod Calotropis Procera — Seeds Of Hope

Pollinator Plus:

Nature photographer Maria Firpi says to keep an eye out for hummingbirds and bees!

This section is a work in progress because there are so few North American “gardening” reports about this milkweed species. If you have experience growing procera, please comment below to shed some light on this mysterious milkweed.

note: this is not Calotropis gigantea (giant milkweed), but you can click here to leave comments on that species.

Resources:

1. Buy Calotropis Procera Seeds

2. Calotropis Procera on eBay

Click here for More Milkweed Ideas to Enhance your Monarch Butterfly Garden

Most of the photos above are courtesy of nature photographer Maria Firpi. Her blog features flora and fauna located in Puerto Rico and South Florida. Check it out here.