Shades of preference. Most hardy ferns prefer dappled rather than deep shade. The amount of sun a fern tolerates depends on the moisture content of the soil—the wetter the soil, the more sun-tolerant the fern.
Multiply your ferns. Collect spores for propagation by cutting off a healthy frond whose spores are just turning dark and drying it on a sheet of white paper. The spores will fall off and look like fine dust. Remove the frond and crease the paper to gather the spores for sowing.
Sow the spores by tapping the paper to sprinkle them in sterile soil in a sterile pot; mist lightly. Cover the pot with plastic wrap and stand it in a dish filled with a few inches of water. Set in a warm spot in indirect light and maintain the water level until the soil surface is covered with the tiny heart-shaped growths called prothalli—in six to twelve weeks. Gently lift them out and transplant them in a soilless mix; keep moist until they have developed fronds and can be planted out.
Dividing ferns. Dig up root clumps in early spring and, depending on their size, divide into two or three pieces with your hands or a spade. Make sure at least one growing tip, where new fronds are produced, is present on each division. Transplant and keep well watered until established.
Save time, save water. Each year at winter’s end, mulch ferns with leaf mold or unfinished compost to keep soil cool and moist. Water ferns only during long dry spells.
Don’t rake around ferns in spring or you’ll damage the young fiddleheads; do your spring cleanup by hand instead. In fall, rake gently so as not to disturb the shallow roots. Let some leaves remain as mulch.
With most ferns, fertilization is not necessary. Simply add compost to the planting hole and spread more on every year. It will provide nutrients and improve the soil’s water-retaining capacity as well.
Don’t cut back in winter—the dry fronds of deciduous ferns protect the base of the plant. Once the new shoots show in spring, prune old fronds off at the soil line.