The plant likes plenty of light but not full sun. It does well under plant lights. It thrives in temperatures between 65 and 75 degrees. But temperatures under 60 degrees or over 75 degrees are not good.
The Dieffenbachia likes plenty of water and its soil kept moist during the growing season from March to October.
Fertilize with a complete liquid plant fertilizer once every other week during this time. During the winter months do not feed and cut back on the watering. Use well drained soil. Two parts peatmoss and one part perlite are recommended. An African Violet soil mix works also.
Early spring before growing season starts is the time for repotting. Do not overpot.
Propagation can be done by cutting off the top shoot and placing it in well drained soil of 50% peatmoss and 50% perlite. The stems will root also. Place the stem on its side with about 1/2 the stem buried in the soil with the eye pointing upward. It will take 2-4 weeks to root keeping the temperatures around 72 degrees.
The biggest enemy of the Dieffenbachia is bacteria. It causes the plant to rot, the leaves to become slimy, smelly and the stems become soft. If this happens there is nothing you can do but just throw the plant out.
Brown Spotting can be caused during winter months by over fertilizing or allowing the plant to dry out too much between waterings.
The difference between brown spotting and bacteria is that with bacteria the diseases are "wet" and brown spotting is dry.
During winter months watch for red spider mites on the underside of leaves. Mealybugs hide at leaf axils and aphids appear on new growth and suck juices from the plant. Use sprays such as Malathion or Neem oil.
Be aware that The Dieffenbachia plant is poisonous if eaten. It has been said "one bite paralyzes your voice, two paralyze you, while three are supposed to be fatal". Avoid getting the sap in your eyes or mouth. Wear gloves when you handle the plant.
Even with these downsides the plant is a beautiful addition to your home .