Can My Dog Die if She Eats a Succulent? He spent extra time explaining to me how scale spreads and what I could do to stop it. Some have tiny sitting areas, arches or birdbaths. However, you need to be careful with your watering regime because too much or too little water can cause harm to your plants. To learn more about the dangers of overwatering a cactus, please visit our article "5 Dangers of Overwatering A Cactus". These are typically USDA zones 9-11. You don't need to worry if your locality falls outside this range. These plants are hardy and can tolerate all temperatures.