Boston fern hanging pots
Can I use a fragrant (lavender) Epsom salt added to water for fertilizing it?
A fertilizer with an NPK ratio of 20-10-20 is the correct one for your Boston Fern. Fertilize every 4-6 weeks with a water-soluble fertilizer diluted to one-quarter strength. You can also use organic fish emulsion.
This article provides some additional tips on fertilizing your Boston Fern: