Ostrich ferns, which are native to the Eastern United States and parts of Eurasia, are named after a tall bird for a reason: they tower over most other ferns. Recently, a "giant" ostrich fern (Matteuccia struthiopteris var. struthiopteris "Jumbo"), has appeared in the nursery trade, and, as one might imagine, it is even more impressive in the garden. Most ostrich ferns top out at 3 to 5 feet, but the giant variety has many more fertile fronds, giving it a more robust appearance. Grow the ferns from spores, if you have time; from divisions, if you want quicker results; or simply buy the plant.
Cut a brown, feather-like frond from the centre of the fern in late August and dry it for three days. Invert it onto a white sheet of paper and the next day gather the spores from the paper. Refrigerate spores in a paper envelope if you are unable to plant them immediately.
Fill a new, 3- to 4-inch plastic pot with a seed-starting mix and tamp the soil to firm it. Microwave the pot for two minutes or until a meat thermometer inserted into the pot's centre measures 65.6 degrees Celsius. Seal the pot in a new, clear plastic bag and cool it for an hour.
Scatter 1/8 tsp spores on the cooled soil. Insert the pot back into the plastic bag, seal it and place it in a sunny window where temperatures stay between 18.3 to 23.9 degrees Celsius. Ferns germinate quickly and require transplanting several times over a period of 12 months before they are large enough to plant outdoors.
Search for ferns in spring, because they transplant easily at that time of year. Locate a patch of giant ostrich ferns in a friend's yard or ask permission to dig ferns if the plants are located elsewhere.
Locate the smaller ferns that are attached to larger plants by underground rhizomes. Look for the brown, cone-like structures from which the leaves emerge and using a sharp trowel or narrow transplant shovel, carefully dig one or more of them. Do not expect to see a large root system; the transplants will form more roots once they have been relocated.
Transplant the small ferns immediately to a shady or partly shady area with evenly moist soil and water well every week, especially if there is a drought. Site them in organically rich soil, if possible, though they will tolerate some clay. Locate these tall plants in an area sheltered from wind. Do not fertilise.
If you cannot find giant ostrich ferns in your friends' yards, you can simply buy one. Grown in the right conditions, it will multiply quickly and soon you will have plenty to divide.
All ostrich ferns have the potential to be invasive. Grow giant ostrich ferns where their tendencies to spread will not overrun other plants, or remove the young ferns each spring to keep the spread in check.