Question
Spike is a 5' tall Euphorb in my office.  I don't know his variety, but I think fractiflexa.  He is single stalked and has a cross-section of five deep fins capped with twin-pointed spines.  Spike used to have two stalks, then one died, turning brown about three feet from the soil line.  Now four months later, the other stalk is turning brown at the soil line and softening.  I assume it too, is a goner.  I have 2 questions: (1) What is going on? and (2) Can I propagate cuttings from the remaining stalk?

Answer
Gary,

It is hard to say, although rot from too much water may be the culprit. You plant actually sounds like either E. ammak or E. ingens which can get that tall without branching. Yes you can propagate it, just be very careful not to get the white sap from the plant on you. After you make the cut, let it sit and dry out for at least 2 weeks before replanting. If it roots, it will take up to a month or more.

Water only when the soil is dry and keep it out of direct sunlight and it should be fine. Hope this helps.

Sincerely,

Greg