This depends on several factors, like the climate in your living area, what month of the year it is, the weather conditions, etc. Dahlias in general are not winter hardy in colder regions, therefore they need to be planted when the last frost date has passed. In most regions, this is typically in May.
If you live in an area with a warmer climate, such as USDA zone 8 or higher, then you can plant them already early in spring.
However, in both climate regions, it's important to ensure that the soil is well-draining, fertile, and moist, as dahlias prefer slightly acidic to neutral soil pH. Before planting, prepare the soil by adding compost or organic matter to improve its fertility and drainage.
Plant the tubers at a depth of around 5-6 inches, and water them well after planting. With proper care and maintenance, Striped Vulcan dahlias can grow and bloom beautifully in the ground.