What is too cold for spring bulbs?

Spring bulbs generally thrive in temperatures between 40°F and 60°F (4°C to 16°C). When temperatures consistently drop below 20°F (-6°C), it can damage the bulbs, especially if they are not well-established or if they are coming out of dormancy. Additionally, prolonged exposure to frost can hinder their growth and flowering. Therefore, it's important to protect bulbs from extreme cold, especially during early spring.