Mothballs are highly toxic when ingested by children, pets, and beneficial animals, so I don't recommend their use. They've also been reported to cause cataracts in humans and animals.
Your purple rose, Andrew, could be a Gallica, which blooms only once a year, but for a long time, usually for the whole month of June in your zone. The foliage and thorns look like those of a Gallica rose. I also suspect it's a Gallica because you had better luck with the cutting from the base. Gallicas spread by means of suckers, and these suckers root quite easily. There are many purple gallicas, but the most popular are Belle de Crecy, Charles de Mills, and Cardinal de Richelieu.
If your rose is a Gallica, it should be pruned as soon as it has finished blooming. If you wait too long after that, you're likely to cut off the start of next year's buds.
