Cleistocactus strausii f. cristata - Crested Silver Torch CactusLight Needs lots of bright light! This plant will love your sunniest window; if in doubt, choose a South or West facing window ledge. Water Allow the soil to completely dry out in between waters. When you do water, completely soak the soil. Don't water over winter. Pet safe Non toxic, but spines aren't that fun to eat so best to keep away from pets and small humans.