The size and conditions of the succulent will affect how big it grows. Two factors can help plants tell when winter is here: the shorter days and the lower temperature. It can cause a severe allergic reaction if it gets in contact with your skin. The majority of succulent plants are non-toxic to your cats or dogs; however, some are toxic and can cause skin irritation or nausea when ingested. Succulents are dependent on the soil they are placed in for their nutrients. It is obvious that the soil can have a significant impact on the rate of growth.