It sounds like they might be suffering from stem rot or other fungal disease. Both these plant prefer dry conditions so don’t water them and, if you do, make sure to moisten the soil and not the leaves. Wet weather is bad enough for this problem and spraying your flower and vegetable gardens with water just makes things so much worse for the plants. You could also start spraying now, before the problem shows up with a fungicide like sulfur, copper, Neem oil or Seranade which are all organic and can help prevent certain fungal diseases. Always read and follow the directions on the products label.