Ferns range in varieties and display a wide array of leaf appearance, from feathery to thick. Most fern varieties are highly adaptable and are easily grown indoor and outdoors. Hardy fern varieties such as Southern Maidenhair, Northern or Common Maidenhair, Ebony Spleenwort and Lady Fern are cold- and heat-tolerant and are easily cared for. It is important to check your fern varieties specific needs to prevent over-watering or planting it in the wrong location.
Test the pH of the soil to determine whether it is suitable for growing ferns. Use a store-bought pH test or by send soil samples to your agricultural extension office. Ferns prefer a soil between 4 and 7 on the pH scale, says Clemson University Extension.
Plant ferns in a well-draining soil with lots of organic matter. Add a 2-inch layer of composted pine bark or organic material to the top 10 inches of clay soil to make it suitable for fern planting using a rototiller. Plant in a moist, shady spot.
Keep the temperature indoors between 65 and 75 degrees F during the day and 10 degrees cooler at night for indoor ferns, recommends the University of Vermont Extension.
Water the soil the fern is planted in to keep it evenly moist. Do not allow the soil to get excessively dry. Water indoor ferns until water drains out the bottom of the pot into the drainage tray, suggests the University of Minnesota Extension. Drain the tray once the soil has had a chance to soak up the excess. Keep outdoor soil moist but not excessively wet.
Fertilize the fern in the spring just after new growth has begun. Use a slow-release fertilizer such as Osmocote 14-14-14 to prevent damage to the fern.
Add a 2- to 3-inch layer of leaves to the base of the fern plant in the fall as a mulch to add nutrients and retain moisture.