A full sun position will ensure your plant thrives and remember to water moderately. Keep in mind when planting that Purple Danube is thought of as very hardy, so this plant will tend to survive through freezing conditions.
Growing Purple Danube from seed
By our calculations, you should look at sowing Purple Danube about 35 days before your last frost date.
Transplanting Purple Danube
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Purple Danube is a very hardy plant.