QUESTION:
Hello Judy! It’s Stephanie from Northwest Territories Canada again! I hope all is well with you. I am worried about this beauty. I am not sure if the yellow leaves and the dying tips are from over watering or the pellet stove making it very dry. Right now the first inch of soil is dry but the rest is lightly moist. Any thoughts?
ANSWER:
Hi Stephanie,
Here are some reasons what might cause yellow/brown on dieffenbachia leaves:
Excessive fertilizer or too many chemicals in the water you are using. To get rid of accumulated salts, chemicals, and fertilizer, flush the plant with distilled water several times. Never use water that has passed through a softener (too salty). Allow your household water to sit out over night before using it. Fertilize only when the plant is actively producing new leaves. Most dieffenbachias need to be fed every two weeks in the summer and once a month in the spring and fall. Never fertilize in the winter. Excess plant food causes browning around the edges of the leaves.
Brown tips on your dieffenbachia’s leaves could also be caused by uneven watering. Keep your watering practices a little more regular and never let your plant sit in water.
It also looks like the plant could use a good pruning to help it become a full bushy plant. I would cut the top 1/3 off the tallest stem. This plant is very poisonous. Always wear long sleeve shirts and gloves when pruning to prevent the toxic sap from getting on you. You can read more about poisonous houseplants in my book Don’t Feed me to Your Cat: A Guide to Poisonous Houseplants