Calotropis procera, Apple of Sodom, Milkweed, 30-100 seeds
Other common names: King's crown, Rubber bush
Calotropis is a spreading shrub or medium-sized tree reaching 2.5 to 6 m in height. It has a deep taproot, 3-4 m deep, and a secondary root system with woody lateral roots that may rapidly regenerate adventitious shoots when the plant is injured. The stems are crooked and covered with a fissured corky bark. The grey-green leaves are 15-30 cm long and 2.5-10 cm broad and have a succulent and waxy appearance, hence the name procera, which means wax in latin. The flowers are pentamerous, small, cream or greenish white at the base and purple violet at the extremity of the lobes. The fruit is a fleshy and inflated, up to 10 cm or more in diameter.
Calotropis procera originated from the Afro-Asian monsoonal regions. It spread on an arc expanding from north western Africa (Mauritania, Senegal), through the Arabian Peninsula and Middle-East to the Indian subcontinent. It was introduced to subtropical America, the Mascarene Islands, drier parts of Australia and probably South-East Asia.
Calotropis is found from sea level up to an altitude of 1300 m in semi-arid conditions on sandy soils. However, it can withstand a wide range of soil textures. It is tolerant of soil salinity and of beach front salt spray. On excessively drained soils, it can withstand up to 2000 mm annual rainfall. It quickly becomes established in open habitats with little competition, along degraded roadsides, lagoon edges and in overgrazed native pastures and rangelands. When Calotropis is damaged, it readily develops suckers from the roots. Calotropis seeds are spread by wind and animals and may be transported long distances in flood waters.
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.
- Prone to aphids like most species.
- Has been reported to be invasive in India, Africa, Hawaii, and Australia
Germination method
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. Plants do not flower in year 1 starting seeds.
Container garden option
Do not overwater! C. procera does not like having wet feet
Overwinter in pots for annual zones.
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