Great article Chelle
I am a person that needs to know the "why" of things, so I hope you don't mind if I add a little more information for Liza.
This is a very, very general explanation.
For repeat blooming roses we generally dead head the spent blooms before the rose has a chance to create hips so that we can stimulate the rose to put out more blooms.
The plant cycle is for the rose to create a bloom to attract pollenators to fertilize the bloom so that it can set seed and continue the species. When we are dead heading, taking off the spent blooms, we are interrupting that plant cycle because we are not allowing the rose to set seed and form hips. In a sense, the rose "knows" it has not performed its function of continuing the species, so it starts over and puts out more blooms to get pollenated. That's how we get repeat bloom on our roses. Of course, this is only true for those roses that are genetically programmed to bloom more than once in the season.
Some roses will continue to bloom a lot even though they have not been dead headed and have formed seeds, but for the purposes of this thread, I am ignoring those roses
Most roses, once they have set seed kind of tell themselves they've done their job and stop blooming.
In your climate, you stop dead heading your rose some time in October to allow the plant to complete its normal plant cycle and rest during the winter. The rose will set seed and form hips where you have not removed the spent blooms. On some roses, those hips are simply beautiful and they are the fruit of the plant.
Allowing the plant to complete its normal plant cycle helps create stronger roses, in most cases. As always, it depends on the rose.
Smiles,
Lyn
