Fertilize mother fern plants with a balanced fertilizer -- like a 14-14-14 mix -- in the spring. The best time to fertilize is right when you see new fronds growing near the soil line. Sprinkle 4 tablespoons of fertilizer on the soil around the base. Water to dampen the soil and help release the fertilizer into the ground. Use a soaker setting on a hose until the soil is damp about 4 inches deep.
Keep the soil moist year-round, watering whenever the top 1 inch of the soil starts to dry out. Water slowly with a sprinkler or soaker setting on the hose, allowing the water to seep into and dampen the top 3 to 4 inches of the soil.