Check for watering weekly... allowing the soil to dry to the touch about 1/3 down the pot. Yellowing leaves can be an indication of over watering, under watering or simply just normal leaf drop.. Under watered plants will shed a large amount of totally yellow leaves from the lower portion of the head, whereas a plant that has been over-watered, the leaf will yellow from the tip towards the stem. Feed only once a year... the "Dragon Tree" does not like to be fertilized.