Use Miracle-Gro® Water Soluble All Purpose Plant Food for larger Boston ferns and those grown outdoors, and Miracle-Gro® Indoor Plant Food for smaller indoor Boston ferns. The amount you use to fertilize your fern will vary depending on its size, so be sure to follow the instructions on the label.

What is best fertilizer for ferns?

Fertilization. Ferns are relatively light feeders compared to many other foliage plants. They prefer a balanced fertilizer, such as 20-10-20 or 20-20-20, with micronutrients applied at approximately 200 ppm nitrogen. Too much nitrogen can cause tip burn on the roots and leaves if the plant becomes dry.

What to put on ferns to make them grow?

Epsom Salt for Ferns can do wonders! It can make your fern plants greener and lusher.