There are many varieties of Athyrium, some of the most common are Lady fern and Japanese painted fern. Many people have Lady fern in their homes as house plants, but the plants do well outdoors in gardening zones 4 to 9. This deciduous perennial will grow from two to three feet tall and makes a beautiful hanging plant, too. They are easy to grow and popular among landscapers for border plants and planting under trees. They also can be used gracefully in rock gardens, provided they are not in full sun.
Dig a hole twice the size of the root ball. Add a few handfuls of compost to the soil, whether planting in the garden or in a container. Plant in early spring in a mostly shaded location.
Take the fern out of its original container and tap off the soil around the roots. Gently spread out the roots and place in the hole. Place the fern so that the crown is slightly higher than the top of the hole. The crown of the plant is where the stem meets the roots.
Fill in with soil until it covers half of the root ball. Water so that it compacts the soil around the roots and leaves no air pockets. Continue to fill with soil, then water again. Fill to the top with a little more soil and press down firmly, leaving the crown just above the soil level. If you're planting more than one, space them about two feet apart.
Mulch around the plants with a pine needle or fine pine bark mulch, but leave it an inch away from the crown. This will keep the fern's soil moist and keep down weeds. Replace the mulch each year in the fall or spring.
Water the ferns every other day until the roots are established. You will notice new growth or that the plant is getting bigger. Once this happens, cut the watering to once a week, less in rainy weather and more if it's particularly hot and dry.
Fertilize the fern after it has become established in it's new location. Use a general purpose plant fertilizer that is a little heavier on the nitrate side. This will encourage a bushier and greener foliage.
Divide and transplant the clumps in the spring through early summer if you wish to start new plants in a different location.