Q. Hi – I have had a Christmas cactus for about 2 years now. Its leaves are now getting about 12 inches long, and very heavy. Am I watering it too much? I water it twice a week. Also, I recently added coffee grounds to help it. Not sure I should have done this. HELP! Candice Zoot – Denver, CO
A. The size of your plant is not an indication that you are overwatering your plant. How much you water depends on the preference of the plant you are growing and the conditions in which it is growing. Christmas cacti are epiphytic so instead of living on the ground in a desert, lives in the crotch of a tree in a jungle just like orchids. But like its other cacti relatives they have evolved to live in challenging water environments. The desert simply provides little rainfall. Although jungle evironments are much wetter the crotch of a tree doesn’t give the root system much to work with as far as water holding capacity. So the plants have adapted periodic dry conditions. I suggest using your finger and feeling the top two inches of the soil and when this has become moderately dry water again. This may work out to be twice a week as you have been doing all along. Overwatering of Christmas cactus often results in the root and/or stem rotting. Coffee grounds are a fine addition of organic matter container but they also can reduce the pH of the soil (which is not necessarily bad but it is good to know). Too much around the stems of the plant may retain water around the stems so keep the layer thin. Christmas cacti also prefer a lighter soil mix that has good drainage.