"My fifth graders were reading The Kapok Tree and discussing the rainforest," reports Carol Anne Margolis, Science Lab Coordinator in Smithville, NJ, "when we decided to try to grow ferns as a way of bringing a little bit of the rainforest right into the classroom. Although it took a could months to see much growth, it was an easy project and each student ended up with several ferns to take home or put into a terrarium."
Just when you though you had plant propagation figured out -- seeds, cuttings, bulbs -- a whole new twist: raising plants from spores. It's not so difficult to do. Read on...
Ferns, the only non-seed plant with roots, stems, and leaves, are among the most ancient vascular plants. Over millions of years, many thousands of fern species have evolved and adapted to all parts of the globe. Many of the ferns typically used as houseplants in our climate are, in fact, native to more tropical regions.
Although most reproduce vegetatively by growing from underground stems, ferns can also reproduce by single cells called spores that are widely dispersed by wind. Although other plants like mushrooms and mosses also reproduce by spores, ferns are the easiest to grow in the classroom.
On the undersides of delicate fern fronds (the plant's compound leaves), microscopic, dustlike spores are encased in structures called sporangia. Clusters of sporangia called sori are the scalelike bumps one can see on the underside of the fronds. When the sorie turn brown (outdoors, typically after midsummer), they are ripe and ready to release spores. Sori that are ragged looking (you can tell by using a hand lens) have probably already opened and released the spores.
You can try to collect your own fern spores by tapping the leaves over an envelope if you find ferns at the appropriate stage outdoors, in greenhouses, or at home. But since not all species are easy to propagate from spores, consider requesting fern spores for classroom projects from the American Fern Society.
You can use a soilless growing mix or a commercial "peat pellet" (e.g., Jiffy-7) for starting your fern spores. In either case, keep the growing medium, containers and other materials extremely clean to avoid contamination from fungi and other life forms that also thrive in the same conditions. To plant you fern spores:
* Thoroughly moisten your growing mix. If you're using a commercial peat pellet, soak it in a half cup of warm water.
* Put the moist growing media in a clean container. If using a peat pellet, you can squeeze out the excess water and put the enlarged pellet in the bottom of a class petri dish with some water in the bottom.
* Gently sprinkle the fern spores over the surface or use a cotton swab to apply them. Tamp the soil gently with the bottom of a clean pot.
* Create a mini-greenhouse. If you're planting with soilless mix in a pot, you can cover it with a piece of class or a plastic bag fastened to the pot with a rubberband. If you have a peat pellet in a petri dish, invert a plastic cup over the dish. In either case, thee should be enough moisture maintained so you don't have to water again. If it does look like it's drying out, place water in the bottom of the container, but never water from the top.
* Leave the container in moderate, not bright, light in a warm spot in the classroom. (It could dry out if left in bright sunlight.)
Depending on the types of fern spores used and the growing conditions, it could take from several weeks to a couple of months until you see signs of growth. Have your eagle-eyed classroom observers watch carefully, since what they do see first may look more like a coat of slime than like any familiar plant!
The first stage that students should be able to observe will look like a thin green slime covering the top. This is actually made from beautiful translucent heart-shaped plants called prothalli. These produce male and female structures that will unite in the film of water. Once fertilization has occurred, the more recognizable leaves which form fronds of the young fern plant will appear. As soon as the leaves are about 2.5m (1 inch) tall, you can gently transplant them to a distance of 5cm (2 inches) into other containers. Once they fill those spaces, they should be large enough to put into separate pots or terraria.
While you're waiting for you ferns to emerge, consider the following activities:
* Study different types of common fern leaves using houseplant and/or outdoor ferns. Collect and classify the leaves, describe and compare the types and numbers of spores, make fern leaf prints, or create a class fern booklet.
* Press ferns between layers of clear contact paper or plexiglass pieces to use as hanging ornaments or placemats.
* Make terraria with ferns, mosses, and other woodland plants.
* Learn about and try some edible fiddlehead ferns. (All ferns go through a stage as the fronds unfurl when they resemble the form on the head of a fiddle, but only some species are palatable!)
* Create an outdoor fern garden. Carefully observe the types of conditions ferns grow in outside to determine how to care for them.
* Investigate other living things that reproduce through spores (e.g. mushrooms, mosses, lichens).