"Ferns pre-date the dinosaurs - they have survived for hundreds of millions of years."
Selecting the right ferns
Ferns as a species are highly resistant to both pests and disease - making them ideal for the beginning gardener. Nevertheless, selecting the right ferns can be overwhelming - after all, there are a lot of species out there. Within the world of ferns there are several cultivars (plants that have been bred) that homeowners and landscapers tend to pick. However, most home garden centers only carry a very limited variety of species and cultivars. Ed Lyon, the director of Reiman Gardens in Ames, suggests mail ordering if you’re looking for a more diverse selection of ferns.
Lyon recommends athyrium ferns, like the common lady fern and Japanese lady fern, for Iowa. He also encourages checking out some native ferns, including the sensitive fern, royal fern and cinnamon fern.
Where to put ferns
Ferns do the best in shade. A lot of new gardeners focus on sunlight, but Lyon notes we should also be focusing on shade - particularly from a design perspective. "When you're designing, you want to look at contrasting your textures and your forms." Just getting started with your garden? Lyon suggests hostas and ferns as two plants for the best visual contrast.
Keep your ferns under control
Most ferns won't spread like wildfire once you plant them. But Lyon warns of the three ferns that will: ostrich fern, bracken fern and hay scented fern. Ostrich fern is the most well known. "That very tall fern you see around a lot of people's houses, that just masses so thickly, that's ostrich fern." It spans about waist high and grows in what horticulturists call "ascending form." Bracken and hay scented fern are natives. "They are also two that if you happen to put in a garden setting will probably run rampant and you'll regret doing it."
But spreading ferns doesn't have to be a bad thing. In the never-ending search for ground cover, ostrich ferns, (though tall) can serve as a nice ground cover, especially on the north side of a house.
Plenty of water and limited sun
Ferns need lots of moisture - and while they're good at retaining water, too much direct sunlight will make ferns shrivel up. That's why it's important to think about shady places when you're picking your planting location.
Additionally, in a dry year, don't worry if you start to see your ferns go away. They'll go dormant to protect themselves, but as long as the change in temperature is somewhat gradual, they’ll reappear once water comes back. If you don't have a lot of shade in your yard, Japanese painted ferns are some of the most sun resistant.
When to plant your ferns
Ferns are tough, and do well planted anytime during the growing season in Iowa. If you need to move existing ferns, wait until late summer or early fall if at all possible. Once moved, water consistently to avoid drying out. If the ferns are in a sunny area, consider using some shade cloth as they settle into their new home.
Spread the ferns!
Up for a challenge? Ferns reproduce by spores in the wild. Lyon says that it's not too difficult to propagate them yourself, but the process can be very time consuming. For the rest of us, dividing ferns is the way to go. Depending on the species, some will multiply rapidly, and some will take three or four years before a large enough clump exists to divide.