Friday, May 27, 2011

Boston Fern

I’m a little undecided on how I feel about ferns. On one hand, I really like them because they’re interesting and very different from the regularly-available plants at the local greenhouses such as the usual selection of African Violets, Dieffenbachias, Aglaonemas and Dracaenas. But on the other hand, I don’t seem to like them enough to want to grow them on a permanent basis inside my home. They fall into the ‘try it at least once’ category; the types of plants that I’ll grow once (and only the ones that appeal to me) to gather hands-on experience about their needs and never bother to replace if they die (with or without my help). I don’t know why this is. They’re certainly popular enough. And quite attractive. But there’s just something about them that doesn’t pique my botanical interest. Aside from the Platycerium bifurcatum, the staghorn fern, that I think is a really cool-looking plant. And Asplenium nidus, Bird’s Nest Fern, also very cool.

Caring For A Boston Fern

Regardless of how I feel about this group of plants, the Nephrolepis exaltata `Bostoniensis', native to the American tropics and subtropics, definitely deserves to have a profile dedicated to it on my blog. It’s an extremely well-liked houseplant that is often found growing in hanging baskets in homes and offices.

Although ferns are a very ancient family of plants and one of the earth’s oldest (long predating dinosaurs, never mind humans), the Nephrolepis exaltata `Bostoniensis' is a fairly recent discovery. It was a mutation that was discovered in a shipment of Nephrolepis exaltata to Boston from Philadelphia in 1894, thus its common name. Because of its graceful, arching fronds and delicate foliage, it proved to be an immediate success and quickly became a favourite. It has become one of the most popular houseplants on the market.

Depending on who’s telling the story, the Boston fern can be very easy to grow or very difficult. I know many indoor gardeners that will argue emphatically that the Nephrolepis exaltata `Bostoniensis' is as carefree as it is popular. I personally don’t agree; I consider it a bit of a challenge and wouldn’t recommend it to a beginner or give it as a gift to someone who is very inexperienced with indoor plants. Yes, I’ll concede that they’re not really hard to grow indoors, but because they will not tolerate neglect at all, they’ll prove to be quite exasperating unless you fulfill their needs completely. And although you may manage to keep them alive with slapdash care, they certainly won’t look their best.

Okay, so what do they need?

To start, Nephrolepis exaltata `Bostoniensis' needs ample humidity; this is absolutely essential to its survival. The average home usually does not offer the amount of humidity that this plant desires, especially during the winter months when the heating system is turned on, so you will have to remedy the situation. Add a humidifier nearby, place the plant on a pebble tray filled with water, double-pot and fill the spaces in between the containers with sphagnum moss and keep it moist at all times, group plants together to form a microclimate with higher humidity or grow the plant in a room naturally higher in humidity. If you are growing quite a few plants that require above average levels of humidity, consider purchasing a hygrometer to measure the moisture in the air. This will help you determine whether your plants are receiving adequate humidity and what type of action you should take if they aren’t.

Despite popular belief, Nephrolepis exaltata `Bostoniensis' is not a good choice for a dark, shady location. On the contrary, this plant requires a lot of light. Place your plant near a window where it will receive plenty of indirect light. Some direct sunlight from an east or west-facing window during the fall and winter seasons is handled well, but you must protect your Boston fern from the hot rays of direct midday sun during the summer months. The windowsill of a window facing north is also an ideal location.

Nephrolepis exaltata `Bostoniensis' likes its soil damp but not soggy. Use an airy, fast-draining medium and keep it moist at all times. Water thoroughly until it runs out of the drainage holes; allow the plant to dry partially before watering again. Check on your Boston fern regularly if it is sitting in a room that is warm; it will dry out much faster and may need to be watered more often. Reduce watering in the winter when growth slows down, but never allow the plant to dry out completely. If the soil becomes too dry, the fronds will die back.

(Note: I have not tested this plant in hydroculture yet, so I can’t comment on it. If you have successfully converted one, share your experience.)

Like all its cousins, this fern prefers to be grown in an area that is slightly cool. The best temperature range is between 16°C (60°F) – 21°C (70°F), with slightly cooler levels at night. The plant may tolerate a location that is as high as 24°C (75°F) if the humidity is kept very high, but it will suffer and decline if the temperature rises any higher. Keep your plant far away from heat sources and circulate the air to keep it fresh. Open windows regularly and run floor or ceiling fans. Wash the leaves often to keep pests at bay, especially spider mites. Feed with a liquid fertilizer diluted to half strength every two to three weeks or once a month during the growing season; do not feed in winter.

If you’re going to grow only one fern, then this is the one. Nephrolepis exaltata `Bostoniensis' may be inflexible about its needs, but if you can fulfill them, it will grow beautifully inside your home. Fresh air, bright light, moist soil, cool temperatures and ample humidity – is that too much to ask for?


  1. It's probably been close to 20 years since I've attempted to grow any type of fern. (except for the ones I have in my yard - they are doing great) I killed off so many that I gave up. We are pretty dry out west, combine that with our cold dry winters and central heating...I found it impossible. Part of the problem was that I was very busy with young children and didn't have the time to mist a fern lol!
    I realy like them though.

  2. It's been a very long time since I've grown a fern, too. I do have two in my garden courtesy of a garden friend who lives here. She gave them to me last year and they're doing great. I don't think I'm ever going to grow a fern indoors; they need things that I can't easily provide, mainly humidity.