Question
Tom,
  I am concerned with some of my chrysanthemums.  The stems have small black raised bumps on the stem.  At first I thought it might be either sprouting of new roots because of drought stress, but they aren't even near the soil line.  Bumps are not in any regular pattern or spacing. I thought they also might be a scale.  No honeydew, no sooty mold.  Root development is not great.  Only on my dark reds not on the yellows or orange cultivars.

Answer
Hi Laura,
Thanx for your question.  It does sound like scale to me.  Use a mix of 1 part alcohol to 8 parts water and a few drops of dish soap (to disperse) and spray on the plants, once a week until scale is gone.  Another thing you can use is Sun Spray Ultra Fine Horticultural Oil.  The other alternative is to take a sample of an infected stem to your local County Extension Horticultural agent and they can diagnose for sure.  Let me know your location and I'll get you contact info.  I hope this helps.
Tom