Cleistocactus strausii
The cactus prefers free draining soils, strong sunlight, but not high temperatures — in fact it can withstand hard frosts down to -10 °C. In its natural habitat it receives plenty of water during the summer, but almost none over the winter. In cultivation, watering too much in winter often leads to root rot.
Bundala National Park
The seeds of the Opuntia cactuses (called Kathu Potak in Sinhala) are spread by macaque monkeys, and perhaps other animals and birds, that eat the fruits. It is also spread by people cutting down the cactus but leaving the cuttings, which then re-sprout. No biological control measures have been carried out with the moth "Cactoblastis cactorum" so far. Manual removal of the cactuses will be impossible as the area where they have spread over is vast.