The term "fern" refers to any of about 12,000 species of plants that do not produce flowers or seeds, instead reproducing by spores.
Ferns have been in existence for over 300 million years. Many ferns are easily recognizable because of their fronds, or lace-like leaves. However there are many different species of ferns growing around the world, in a variety of habitats and fronds can range in size from less than an inch to well over 12 feet.
To be successful growing ferns, whether in your garden or in your home, you will need to know something about the variety of fern you have and its preferences. Here are tips for growing and caring for some of the more popularly grown fern varieties.
While most ferns prefer a shady location, they don't do well in deep shade, The dabbled shade provided by tree branches makes a better choice.
Ferns can handle some direct sunlight, however, the more sun they get, the more moisture they will need. Few ferns will tolerate dry, hot, sunny locations.
Growing Ferns from Spores
Ferns do not produce seeds, they are grown from spores. Spores look like small dots on the undersides of the fronds. Fern plants can drop millions of spores onto the ground, but only the few that find ideal conditions will grow. If you would like to try growing ferns from spores, you can collect them and plant them just as you would seeds.
To collect fern spores, wait until they darken and fall off the fronds, signaling they are ripe. An easy way to do this is to cut off a frond when its spores are starting to darken in color. Leave the frond in an open paper bag or on top of a piece of paper (indoors, where the spores won't get blown away) and wait for the spores to fall.
Planting Fern Spores
- The spores are quite small and can be difficult to work with. Shaking them off the paper or out of the bag in which you collected them is the easiest method.
- Fill a flat or other container with sterile, moistened potting mix. Shake the spores on top of the mix and press gently, so the spores make good contact with the soil.
- Mist the surface of the potting mix, to moisten the spores and keep them in place.
- Cover the container with plastic and place it in a tray filled with 1-2 inches of water. Move to a warm spot, with indirect sunlight.
- Keep replacing the water in the tray until you see signs of growth. This can take 6-12 weeks, so be patient and don't let the soil dry out.
- The first thing you will see will be small heart-shaped shoots called prothalli. These can be gently lifted out of the container and moved into individual pots filled with sterile potting mix.
- Leave the transplants uncovered, but keep them moist.
- Once the prothalli begin developing fronds, they can be slowly hardened off and transplanted outdoors.
Planting Ferns from Stolens
You may notice long, fuzzy string-like things growing from your fern. These are stolens, or runners, and you can propagate more ferns by layering them on the soil.
Pin the stolen to the nearby soil with a U-shaped landscape staple or a small rock. Keep moist and in a few weeks the stolen should root and send up new growth. When that happens, cut the stolen from the mother plant. The new plant can be transplanted at this point.
Growing Ferns Indoors
Ferns make lovely houseplants, but the humidity in homes is often too low for some ferns to thrive. This is especially true in the winter when the heat is on. Misting the plants will help improve humidity levels as will sitting their containers on a tray filled with pebbles and just enough water to reach the bottom of the fern's pot.
Some ferns that can better handle low humidity include:
- Bird's Nest Fern (Asplenium)
- Boston Fern (Nephrolepis)
- Button Fern (Pellaea)
- Rabbit's Foot Fern (Davallia)
- Holly Fern (Cyrtomium)
- Staghorn Fern (Platycerium)
- Sword Fern (Polystichum munitum)
(More tips for growing and caring for indoor ferns.)
Ferns divide much like other perennial plants.
- The best time to divide them is in early spring when they are just resuming growth.
- Make sure the plant has been well watered either the day before or at least several hours before dividing.
- Lift the plant and pull or slice into 2-3 pieces, depending on the size of the existing plant. Each piece should have a least 1 growing tip where the fronds are sprouting.
- Transplant as soon as possible and water well. Be sure to keep the new transplants moist, until new growth is seen.
Caring for Ferns
Watering: Ferns prefer a moist location, but they can handle a short dry period. They will slow in growth and may turn a bit brown, but they should come back when the dry spell ends.
Mulching: The best mulch for ferns is leaf mold or finely shredded leaves. This mimics the conditions they would have grown in on a forest floor and helps to retain the moisture they need. Add a new layer of mulch each spring.
Weeding: Ferns tend to be shallow rooted. Be careful cultivating around them, especially in the spring, when the tiny fiddleheads are first emerging.
Winter Care: Don't cut back ferns in the fall. Leave the fronds as protection for the crowns of the plants. You can clean up old, dead fronds in the early spring when the fiddleheads appear.