Boston Fern Repotting: How And When To Repot Boston Ferns

Green Boston Fern
boston fern
(Image credit: sdbower)

A healthy, mature Boston fern is an impressive plant that displays a deep green color and lush fronds that can reach lengths of up to 5 feet (1.5 m.). Although this classic houseplant requires minimal maintenance, it periodically outgrows its container-- usually every two to three years. Repotting Boston fern into a larger container isn't a difficult job, but timing is important.

When to Repot Boston Ferns

If your Boston fern isn't growing as rapidly as it usually does, it may need a larger pot. Another clue is roots peeking through the drainage hole. Don't wait until the pot is badly root bound. If the potting mix is so root-compacted that water runs straight through the pot, or if the roots are growing in a tangled mass on top of the soil, it's definitely time to repot the plant. Boston fern repotting is best done when the plant is actively growing in spring.

How to Repot a Boston Fern

Water the Boston fern a couple of days before repotting because moist soil clings to the roots and makes repotting easier. The new pot should be only 1 or 2 inches (2.5-5 cm.) larger in diameter than the current pot. Don't plant the fern in a large pot because the excess potting soil in the pot retains moisture that may cause root rot. Fill the new pot with 2 or 3 inches (5-8 cm.) of fresh potting soil. Hold the fern in one hand, then tilt the pot and guide the plant carefully from the container. Place the fern in the new container and fill in around the root ball with potting soil up to about 1 inch (2.5 cm.) from the top. Adjust the soil in the bottom of the container, if necessary. The fern should be planted at the same depth it was planted in the previous container. Planting too deeply can harm the plant and may cause root rot. Pat the soil around the roots to remove air pockets, then water the fern thoroughly. Place the plant in partial shade or indirect light for a couple of days, then move it to its normal location and resume regular care.

Mary H. Dyer

A Credentialed Garden Writer, Mary H. Dyer was with Gardening Know How in the very beginning, publishing articles as early as 2007.