A Milkweed Tree To Feed Them All
Calotropis procera: Apple of Sodom, Milkweed tree, Rooster tree, Rubber bush, Rubber Tree, Sodom apple, Sodom’s Milkweed, Swallow-wort
Calotropis Procera Plant Specs
- Perennial Zone: USDA hardiness zones 9a-11 (lows -6.7 °C or 20 °F)
- Native to Africa, Arabian Peninsula incl. Saudi Arabia, Western Asia, South Asia, Indochina
- Naturalized in warm regions including southern US, South America, and Australia
- Annual in in northern territory of the United States
- 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
Calotropis Procera 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)
Calotropis Procera 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 plant more native milkweed varieties to support your local ecosystem (Monarchs will use both native and non-native varieties)
Calotropis Procera Plant Propagation
- 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 (not recommended for annual zones unless you plan to overwinter)
- 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 Growing Tips
- Container garden option
- Do not overwater- C. procera does not like having wet feet
- Overwinter in pots for annual zones.
After a couple months of hot summer sun and some slow release fertilizer:
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.
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.
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