The optimum watering intervals for ferns vary, but water them often enough to prevent the soil from drying out and to keep the soil evenly moist. Don't allow ferns to sit in water. Mist them every two to three days.
Ferns require regular watering and thrive in humid environments, such as kitchens and bathrooms. Avoid placing ferns near fans and vents because air dries out soil. Add moistened mood moss around the base of each plant to retain moisture. Planting ferns in terracotta pots, placing the pots in decorative containers and filling the gaps between the pots and containers with moist sheet moss allows moisture to seep from the moss into the pots, keeping the soil moist.