Potted Begonia Stems Have Turned Yellow

Question From: Lovettsville, Virginia, United States
Q: The stems of our two begonia plants (potted) have become yellow; should I worry?

A: If the leaves show yellowing and spots you may have a disease. A spray containing bacillus subtillus, may be helpful. Too much water and/or fertilizer may do more harm than good. Best And Happy Yardening, Nancy