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.
Cannabis cultivation
Hydroponic systems greatly increase aeration of plant roots, and increase control of nutrient uptake. Hydroponic systems are decidedly more difficult to operate for the amateur or hobby grower, as over-fertilization is common, because there is no soil to act as a nutrient buffer. For this reason, many growers now use coconut fiber as a soil-less medium because of its high drainage and buffering capabilities that make it almost impossible to over-fertilize. Additionally, if a hydroponic system fails, the crop has a high probability of dying as the roots rapidly dry out (this is especially true of aeroponic systems).