The Boston fern, Nephrolepsis exaltata “Bostoniensis” is a popular plant grown both as an indoor plant and outdoors. But are Boston ferns annuals or perennials?
Depending on where you want to grow your plant and where you live, you will grow the Boston plant either as an annual or a perennial plant.
In its natural environment, the Boston fern grows as a perennial plant. It is native to semitropical climate, so it likes warm temperatures – both mild warm summers as mild winters.
Are Boston Ferns Annuals or Perennials Out of Natural Environment?
When growing Boston ferns indoors, with proper care, these plants are perennials. This means you will enjoy your plant for years to come, decades even.
The oldest Boston ferns passed down through generations are even older than 100 years. It’s well worth giving them all the care they need.
Read: How to Care for Boston Ferns
How about Outdoors? Annuals or Perennials?
When it comes to growing the Boston fern outdoors, it can be an annual or perennial plant depending on the climate.
While by nature a perennial, the Boston fern doesn’t tolerate low temperatures. If the temperatures in winter fall below 55 degrees F / 10 degrees celsius, the plant can die. Tropical and semitropical plants don’t tolerate cold very well and likely won’t survive freezing temperatures.
If you live in an area with colder winters and want your Boston fern to stay a perennial and bring you joy for many years, you will need to bring it indoors as soon as the temperatures start dropping. You can easily prevent your Boston fern from dying.
If the temperatures drop too much and you leave the plant outside, it will likely die, and you might need to get a new one the next year. Even if the plant is perennial by nature, it won’t live past a year with harsh winters. It won’t spring back to life as temperatures rise in the spring.
The colder temperature might not kill your plants entirely. Only the top part of the plant might die. If the temperatures didn’t drop too dramatically and brought your plant “only” to the brink of death, you might see new growth in spring. Let the plant enjoy winter from the comfort of your home.
It is best not to plant them directly in soil outside if you live in such areas. Boston ferns like to grow in pots anyway, and they can be moved easily if they grow in pots.
How About in Warmer Climate?
If you live in a warmer climate, when the temperatures don’t get too cold, you can have the Boston fern outside all year round.
Be mindful of odd weather phenomenons that can occur every once in a while. Even if your live in an area with historically warm temperatures, they might drop below average on occasion.
You can also opt to plant them directly in the ground if you have a suitable climate all year round. They will happily grow and become gorgeous decorative ferns. If you kept your Boston fern indoors before, you would probably need to adjust your watering routine. Generally, they do need more frequent watering when they live as outdoor plants.