Question
I read the previous question to this but the links provided in the answer are no longer working.  I bought my wife some roses and when the blooms died, we notice new growth on one of the stems.  We have it in water now on the window seal.  How and when can I put it in the ground?

Answer
Florist roses are not like the garden ones and so do not have the vigor to make roots as well. However because you have roots starting here is a method to keep them growing.
Use large zip lock clear plastic food storage bags to create the greenhouse atmosphere. Fold the top of the bag down several inches in order to keep the zipper clean while filling the bag. Place some moist potting soil into the bag. Firm both soil and bag into a ball shape with a flattened bottom. Use a stick to poke a 2" deep hole in the soil not the plastic. Insert the cutting and firm the soil tightly around it. Unfold the top of the bag and close most of the zipper, leaving the last inch open. Inflate the bag to expand it then close the remaining length. Finally, place the bag in indirect light as full sunlight will kill the frail new leaves.
Keep the rose in the bag until it is really putting out many leaves then carefully transplant it into a larger plastic pot with potting soil. Place the pot in full sun but don't fry it no hot afternoon type sunshine. Keep it in the pot until next spring and then plant it in the garden or a container.