How to Fertilize a Boston Fern

A Boston fern used as an indoor potted plant.

Boston fern, known botanically as Nephrolepis exaltata "Bostoniensis," is a widely loved ornamental fern commonly seen used indoors and as a hanging plant on verandas and porches. Also commonly called sword fern in a nod to the spear shaped arching fronds, Boston ferns will benefit from frequent but gentle feeding. Slow-release fertilizers are preferred as there is little chance of chemical burns to the roots or plant tops that can occur with fast-acting chemical fertilizer formulations.

Things You'll Need

• 10-10-10 slow-release fertilizer
• Water

Instructions

1. Fertilize your Boston fern every few months with a gentle slow-release granular fertilizer that is water soluble. Select a complete and balanced product with a guaranteed analysis of 10-10-10.

2. Consult the product label dosing directions and apply as much fertilizer as is recommended for the diameter of the pot in which your Boston fern is growing.

3. Work the grains into the top 1/2 inch of soil being careful not to disturb the surface roots. Water in thoroughly until water drains out the bottom of the pot.

4. Add a dose of the slow-release fertilizer into the fresh potting soil each time you repot your Boston fern to boost soil fertility.

References

• Auburn University: Boston Ferns; Dr. J. Raymond Kessler, Jr.
• University of North Dakota: Questions on Ferns; Ron Smith