We have poinsettia's in our office that we want to turn red for the holiday season. I believe I have heard about a closet procedure, deprevation of light. When to start procedure and how long?

Here is what you have to do.

When the leaves have fallen cut back the stems to leave stumps 4"high. The compost should be kept almost dry and the pot placed in mild, shady position. In early May water and repot the plant, removing some of the old compost. Continue watering and shoots will soon appear. Feed regularly and remove some of the new growth to leave 4-5 strong new stems. the prunings can be used as cuttings.

From the end of September careful light control is essential. cover with a black polythene bag from early evening and remove next morning so that the plant is kept in total darkness for 14 hours. continue daily for 8 weeks, then treat normally. You Poinsettia will again be in bloom at Christmas time, but will be taller than the plant you originally bought.

Lots of work...don't quit your day job....this is why you see them for sale each holiday season. Most people don't have the time for this....and you are already late with the first steps! Good Luck!!!!