I have a crassula left outside in up to 15 days ago, until I saw a yellow leaf. I thought it was a cold shot, I immediately withdrew it but the yellowing with consequent falling leaves proceeds inexorably ... what to do?
It is probable that your plant had the soil too wet before being withdrawn, and that it is therefore suffering because of this; the succulents need less water the lower the temperatures. Check if it is a sporadic event, due to excessive humidity, with consequent slight suffering of the roots and therefore loss of some leaves. If, on the other hand, the leaves continue to fall, it is perhaps the case to repot the plant, in a fresh and dry soil. You will resume watering it in a few weeks, but only if it stays at home, in a climate that is not too cold.