The easiest way to propagate ferns is division, cutting a mature clump or rhizome into sections that each have roots and fronds, then potting them up. Boston ferns and similar types also make runners that root on their own. Growing from spores works too, but it is slow and fussy.
Three ways ferns make new plants
Ferns don’t grow from seeds or root from leaf cuttings the way many houseplants do. They spread through underground stems, send out runners, or release spores. Which method suits your fern depends on how it grows.
| Method | Best for | Speed | Difficulty |
|---|---|---|---|
| Clump division | Ferns with a dense crown of fibrous roots, including many garden ferns and Boston fern | New plant right away | Easy |
| Rhizome division | Ferns spreading by thick underground or creeping stems | Fast | Easy |
| Runners | Boston fern and its relatives | Moderate, the runner roots before you cut it | Easy |
| Spores | Species ferns, patient growers | Many months | Hard |
Clemson’s hardy fern fact sheet calls division the most practical method for home gardeners, and University of Wisconsin horticulture notes that named cultivars won’t come true from spores anyway.
Dividing a fern clump or rhizome
- Water the fern a day ahead of dividing it, so the root ball is moist but not muddy.
- Slide a potted fern out of its pot, or dig around a garden fern and lift the whole root ball.
- For a clump, cut the root ball vertically with a sharp knife into halves or quarters, keeping as many fronds as possible on each piece.
- For a creeping rhizome, cut it into sections that each carry a few inches of rhizome and at least one healthy frond.
- Trim away dead, damaged or mushy roots and old brown fronds.
- Replant each section so it sits at its original depth, in moist, well-draining potting mix or prepared soil.
- Water thoroughly and keep the new divisions out of direct sun while they settle.
Timing depends on the fern. Clemson suggests dividing hardy garden ferns every three to five years, either right after the first fall frost once the fronds have died back or in very early spring just as new growth emerges. Indoor Boston ferns are usually divided in spring. A hollow or dead center, or fronds smaller than usual, are signs a clump is ready.
Rooting Boston fern runners
Boston ferns send out long, thin runners, also called stolons. When a runner touches soil it roots and forms a small new plant. You can help that along by setting a small pot of moist mix next to the parent and pinning a runner’s tip onto it with a bent paper clip. Don’t let that little pot dry out. Once the little plant has its own roots and a few fronds, snip the runner from the parent.
If a hanging basket already has baby plants on its runners, cut them off with their roots attached and pot them individually.
Growing ferns from spores
Look under a mature frond for brown dots, called sori, which hold the spores. When they look ripe, lay the frond on white paper overnight and a fine dust will drop out. Sprinkle that dust thinly over moist, sterilized potting mix, cover the container with clear plastic, and keep it in bright indirect light.
What appears first isn’t a fern but a green film of tiny heart-shaped growths. Fertilization happens there, and Clemson notes it can take as long as six months after that for the first fronds to show up. Keep the cover on and the surface damp the whole time.
Caring for fern divisions until they settle
New divisions have lost roots, so they need gentle conditions for a few weeks. Keep the soil evenly moist but not saturated, give medium bright indirect light, and raise humidity by grouping pots or setting them on a tray of damp pebbles. Hold off on fertilizer until you see new fronds, and skip feeding entirely for garden ferns divided in fall.
Expect a few older fronds to yellow or brown in the first weeks. Snip them off at the base so the plant puts its energy into new growth. Once fresh fiddleheads start to uncurl from the center, the division has rooted in, and you can go back to normal care for that fern.
Frequently asked questions
Can you propagate a fern from a cutting in water?
Not the way you would a pothos. Fern fronds cut off the plant will not form roots, because new plants grow from the rhizome or crown. A small division or a rooted runner can be kept in water briefly, but moist potting mix gives much better results for ferns.
When is the best time to divide ferns?
For hardy garden ferns, Clemson Extension recommends dividing right after the first fall frost when fronds have died back, or in very early spring as new growth emerges. Indoor ferns such as Boston fern are usually divided in spring when they start actively growing.
Why are my newly divided ferns turning brown?
Some browning is normal while divisions recover from root loss. Trim damaged fronds, keep the soil evenly moist, and move the plants out of direct sun and away from heaters or drafts. If the crown turns mushy, the soil is probably too wet, so let it drain better.
Are ferns toxic to cats?
Boston fern, a common houseplant fern, is listed by the ASPCA as non-toxic to cats and dogs. Watch for asparagus fern, which is not a true fern but a member of the asparagus genus. The ASPCA lists it as toxic to both, and eating its berries can cause vomiting, abdominal pain or diarrhea.
Are ferns perennials?
Yes. Hardy garden ferns return every year. Deciduous kinds such as lady fern die back in fall and send up new fronds in spring, while evergreen types like Christmas fern keep their fronds. Boston fern is perennial too, but it survives outdoors only in the warmest zones, so in colder areas it is commonly grown as a houseplant.
