Question
I have had this cactus for almost 10 years and recently it has begun to die - very quickly. I believe, although nobody will admit, that it has been knocked over and plopped back in it's pot.

After some internet research I think it may be a Euphorbia ammak variegated. The main body is a rectangular with threee sided arms growing out the side and upwards. These bottom arms  have become drained and flacid, the base seems to be rotting and is squidgy. The top part and the upper arms seem ok but I fear it is only a matter of time. There seemed to be very little root when I repotted it. Can I take a cutting? I am desperate to save it!  

Answer
Dear Sarah,

It sounds like a Euphorbia. And yes, you can make a cutting. But do so at least 5 or 6 inches above any discoloration or soft tissue. After you make the cut, look at the area and make sure there are no black spots. If not, let it dry for a couple of weeks before replanting.

If you do see a black spot, cut another 5 or 6 inches up the trunk or until you no longer see the black spot. Make sure to clean the knife between cuts with alcohol. Generally euphorbias rot at the base for two reasons, too much water or cold. It should root in a couple of months, just make sure you don't use the same soil and that the soil dries between waterings. Hope this helps.

Sincerely,

Greg