Boston Fern Root Nodules: What They Are & How to Propagate Them

Understanding Root Nodules

When repotting a mature Boston fern, you may notice grape-sized, round nodules on the roots where fronds meet rhizomes. These "bulbils" are natural adaptations that store water and nutrients, helping the plant survive drought. They typically appear late summer to autumn.

Are They Harmful?

No—root nodules are beneficial, not a disease or pest. They enhance the fern's resilience.

Propagating from Nodules

1. Cut a rhizome section with at least three nodules.
2. Plant in moist potting mix or equal parts sand and peat, nodules facing up, just below the surface.
3. Enclose the pot in a plastic bag with some air, place in indirect light at 59–68°F (15–20°C).
4. In 1–3 months, white roots should appear. Once rooted, pot each nodule separately.
5. Keep new plants in a humid, bagged environment until established, then acclimate to normal conditions.

Reviving Old Plants

Even nodules from a dead-looking fern may be viable if they're still green and fleshy. Plant them as above for a chance at regeneration.

This method expands your fern collection or rescues cherished specimens.