A Milkweed Tree To Feed Them All
Calotropis procera: Rooster tree, Sodom apple, Rubber bush, Swallow-wort, Milkweed tree
- Perennial: USDA hardiness zones 8a-11 (lows -12.2 °C or 10 °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
- 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)
- 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 not native so you’ll need to plant other varieties too (I’ve got 3 native and 3 exotic milkweed varieties)
- Start seeds indoors 2 months before final frost
- Sow seeds directly after final frost in perennial zones
- Soak seeds in hot water 24 hours before planting
- Use a for faster germination
- Propagate from woody cuttings. In annual zones, this also allows you to start the season with larger plants. My plants did not flower in year 1 starting from seeds.
- Cuttings from soft stems
Calotropis Procera Growing Tips:
- Overwinter in pots for annual zones.
- If you don’t want additional seedlings next spring, simply cut off the seed pods before they pop open or bind them shut with twist ties or rubber bands if you want to collect milkweed tree seeds.
Seeding is less likely to be an issue for those below USDA hardiness zone 8.
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) so please don’t post about that on this page.)
Until recently, these seeds have been hard to come by for North American gardeners. Now there is one seed option. I am happy to report that 100% of my seeds germinated from this seller so I am confident in recommending them.