If you live in a warm to temperate region, plant your potatoes in late winter. In a truly hot climate, plant potatoes in the fall to grow over the winter. I'd definately give them a try. If they don't grow then at least you'll know not to try sowing them in winter again.
Gentian violet belongs to the group of medicines called antifungals. Topical gentian violet is used to treat some types of fungus infections inside the mouth (thrush) and of the skin. Gentian violet is available without a prescription. This product is available in the following dosage forms: Solution.
Blue spray contains teramycin an antibiotic and is prescription only. As other posters have said purple spray is gentian violet, although the names are sometimes used interchangeably I wouldn't use either on a wound as they both have adverse effects on skin healing. If it is just a small graze then just keep it clean and it will heal.