Singer dahlias are typically considered tender perennials, which means they are not hardy enough to survive freezing temperatures and frosts during the winter months. Therefore, it is generally not recommended to leave Singer dahlias in the ground over winter in areas with cold climates.
Instead, it is advisable to dig up the tubers in the fall after the first frost, store them in a cool, dry place, and replant them in the spring.
However, in warmer climates where the ground does not freeze, it may be possible to leave Singer dahlias in the ground over winter, but it is still important to provide them with proper protection from cold and wet conditions.