Boston ferns are known for their lush green fronds and resilience, but they do have their limits when it comes to cold temperatures. Generally, Boston ferns can tolerate temperatures as low as 50°F (10°C). However, extended exposure to temperatures below this can cause stress to the plant, leading to browning fronds and, eventually, plant decline.
These ferns thrive in a more temperate climate, ideally enjoying temperatures between 60°F and 75°F (15°C to 24°C). If you’re growing Boston ferns outdoors, it’s important to bring them inside or provide protection when temperatures drop near or below 50°F. In outdoor settings, a sudden frost or prolonged cold spells can be particularly harmful, so taking precautions during the cooler months is key to maintaining healthy Boston ferns.