Boston fern is Nephrolepis exaltata bostoniensis (also written N. exaltata var. Bostoniensis). Wisconsin Horticulture traces the Boston form to a natural variant in an 1894 Philadelphia-to-Boston shipment. Staghorn fern (Platycerium) and asparagus fern (Asparagus densiflorus and allies) are different plants.
Wisconsin Horticulture, University of Arkansas Extension (UAEX), Texas A&M, Cornell, UNL Extension, and University of Georgia Extension (UGA) all point at division and runners (stolons) for home plants. Spores are possible for ferns in general, with strong cultivar and sterility caveats below. Commercial tissue culture stays a nursery method.
Indoor clumps and hanging baskets are the usual setting. Outdoor landscape division windows stay brief where a source names them.
Drained-mix technique after a divide is on soil propagation. The main methods across houseplants are compared on plant propagation.
Best way indoors
| Method | Best when | Source support |
|---|---|---|
| Clump division | Crowded pot, root ball you can halve or quarter | Wisconsin Horticulture spring divide. UAEX late-winter divide. UGA Boston and sword outgrow pots. UNL division. Texas A&M lists division |
| Runner or stolon pinning | Long thin stolons with leafy clusters you can pin to mix | Wisconsin stolons. UAEX stolons. UNL runners. Wisconsin 4-H runners. Texas A&M lists runners |
| Spores at home | Not a home method on these sheets | Caveat only. Wisconsin Horticulture: named cultivars will not come true. UAEX: Boston and many kin sterile. Cornell lists spores among methods with no Boston sowing protocol |
Division is the usual home path for a named plant. Runners are the second path when stolons are present. Spores do not get home sowing steps on these sources.
Materials
- Clean sharp knife or long-bladed knife for a tough root ball (Wisconsin Horticulture, UGA)
- Hands for pulling soft sections apart (UNL, UGA)
- Fresh potting mix that drains and stays moist
- Extra pots sized to each new piece
- Hairpins or paper clips to pin runners (Wisconsin 4-H, UNL)
- Room-temperature water to settle the mix
- A spot with medium bright or bright indirect light, out of direct sun (Wisconsin Horticulture, Texas A&M, Cornell)
Division
Wisconsin Horticulture notes that ferns can be grown from spores, but named cultivars will not come true, and most gardeners find division much easier. Repot or divide every few years in the spring. Cut the root ball vertically with a sharp knife into half or quarters. Keep as many leaves as possible on each piece.
UAEX says to divide in late winter every couple of years to keep plants vigorous.
UGA Growing Ferns notes that ferns such as Boston and sword often outgrow pots. Once the plant is free, use a sharp, long-bladed knife to halve or quarter the root ball. Pull each section apart so you can spread the roots in new soil. Water thoroughly. Mist for humidity the first few weeks.
UNL’s general division language still applies: each piece should have some roots. Plants can be divided at any time, though the dormant or rest period is best. Pieces with no roots may be rooted as tip cuttings. That is UNL’s one general line, not a Boston cuttings how-to.
Texas A&M lists division or runners and stops there. That sheet does not supply knife steps of its own.
Wisconsin Horticulture’s spring window, UAEX late winter, UNL any time with rest best, and UGA’s outdoor after-first-frost-through-November window are four different timing notes, not one calendar. Keep the UGA outdoor window on outdoor plants. Do not fold it into an indoor spring or late-winter date.
Runners and stolons
Wisconsin Horticulture describes long, thin runners (stolons) that root into a new plant when they touch the ground.
UAEX notes slender stolons that dangle from the plant. Where they contact soil, a new plant forms. UAEX also treats Boston fern and many kin as sterile and stolon-based rather than spore-based.
UNL G1853 lists Boston fern for division and runners. Place the leafy cluster of the runner in contact with soilless potting medium in a second pot and hold it down with a paperclip or similar. When roots have developed, cut the new plant free. Another option is to cut off leafy clusters with a small section of stem and root them as tip cuttings.
Wisconsin 4-H Propagating and Growing House Plants names Boston fern among plants commonly produced from runners. Set plantlets into soil without cutting the runner yet. Pin with a hairpin or paper clip. Keep moist. Check in two weeks for roots, then cut the runners. That two-week check is the only week figure stated for this step. It is a check point, not a promise that roots finish on day 14.
Spores
Wisconsin Horticulture notes that ferns can be propagated from spores, but named cultivars will not come true.
UAEX treats Boston fern and its many kin as sterile and says they propagate by stolons rather than spores.
Cornell lists spores among methods alongside division and tissue culture from stolons. None of these sources give a Boston-specific spore sowing protocol with timelines. Spores stay a short caveat.
Commercial growers frequently use tissue culture (Wisconsin Horticulture). Cornell notes tissue culture from the stolons. Those are nursery notes, not a home recipe.
Light while propagating
Wisconsin Horticulture wants medium bright light indoors, such as an east window or a south or west window behind a sheer, and not direct sun.
Texas A&M wants bright light and says to avoid direct sunlight.
Cornell wants indirect light.
UGA’s Boston culture line calls for about two hours of indirect sun in winter, early morning or late afternoon, and shade in spring, summer, and fall. That is culture light, not a numbered root week.
A dim corner is easier to judge with numbers. The propagation light DLI calculator estimates daily light at the new pot or pinned runner.
Care after potting
Water the new soil thoroughly after a divide (UGA). Keep moisture consistent (Wisconsin Horticulture). Cornell prefers moist soil and humidity.
UGA wants mist for a humid atmosphere the first few weeks after dividing.
Texas A&M wants normal room temperatures, with a 50 °F minimum. For temperatures above 70 °F, increase humidity with a tray of damp pebbles and mist the foliage daily. That is culture humidity, not a week-to-root clock.
Wisconsin Horticulture says that when the plant is actively growing, fertilizer at half strength every four to six weeks is culture guidance. Cut that back a lot in winter. Do not treat those feed weeks as a rooting timer on a fresh divide.
A simple moist-not-dry reminder after potting or pinning is easy to set with the propagation water change calculator if you track checks on a schedule.
Troubleshooting
A named cultivar from spores does not match the parent. Wisconsin Horticulture says named cultivars will not come true from spores. UAEX treats Boston and many kin as sterile and stolon-based.
A tiny piece has fronds but no roots. UNL wants each division to have some roots. Wisconsin Horticulture wants as many leaves as possible per division. Larger rooted pieces recover more cleanly.
Frond tips brown in dry air after the split. Cornell links overall yellowing to low humidity. Texas A&M raises humidity above 70 °F. UGA wants mist in the first few weeks after dividing.
New pots dry out fast after the divide or pin. Wisconsin Horticulture wants consistent moisture. UGA waters thoroughly after dividing. Cornell prefers moist soil and humidity.
Fronds scorch under hard sun on the new pots. Wisconsin Horticulture and Texas A&M keep plants out of direct sun. Cornell wants indirect light.
Common mistakes
- Applying staghorn pup-and-mount methods or asparagus fern seed or tuber methods on this plant.
- Promising true-to-type plants from spores of named Boston cultivars when Wisconsin Horticulture says they will not come true and UAEX calls Boston and kin sterile.
- Expecting a set rooting time for runners. Wisconsin 4-H only says to check for roots after two weeks.
- Expecting one division date. Wisconsin Horticulture says spring, UAEX late winter, and UGA has its own outdoor timing.
- Leaving a division with no roots when UNL wants some roots on each piece.
- Skipping the pin step on a runner and hoping a dangling stolon roots in air.
- Treating Texas A&M’s division-or-runners line as a full knife recipe. That sheet lists the methods and stops.
- Home-forcing tissue culture from Wisconsin Horticulture or Cornell nursery notes.
People also ask
Division or runners?
Both. Wisconsin Horticulture and UAEX describe stolons rooting on soil contact. Wisconsin Horticulture’s home preference for named plants is division in spring (half or quarters). UNL lists both. Texas A&M lists division or runners.
Can I grow Boston fern from spores at home?
Possible in fern culture generally. Wisconsin Horticulture says named cultivars will not come true. UAEX treats Boston and many kin as sterile and stolon-based. Cornell lists spores among methods. None of these sources give a Boston-specific sowing timeline.
Is asparagus fern the same thing?
No. Asparagus fern is Asparagaceae, not a true fern. Different methods live on its own page.
When do I divide an indoor plant?
Wisconsin Horticulture says every few years in spring. UAEX says late winter every couple of years. UNL allows any time, with the rest period best. UGA’s after-first-frost-through-November line is for outdoor ferns. Those are not one calendar.
Do I need rooting hormone?
None of the division or runner sheets above require hormone for Boston fern. The methods are a rooted clump split or a pinned runner, not a stem-tip hormone recipe.