Nephrolepis cordifolia duffi [nef-roh-LEP-iss] [kor-di-FOH-lee-uh] [duf-EE] is a fern species native to Asia and northern Australia.
It’s one of several varieties of the nephrolepis cordifolia plant that are part of the nephrolepidaceae family.
The nephrolepis (aka Boston fern) is the only genus in the family and contains about 30 different species of ferns.
These plants are collectively called macho ferns or sword ferns due to the shape of the foliage.
The nephrolepis cordifolia duffi variety is also commonly called duffi fern or lemon button fern.
Nephrolepis Cordifolia Duffi Care
Size and Growth
The duffi fern is a compact plant compared to the standard nephrolepis cordifolia.
It reaches a height of about 4″ to 12″ inches.
The arching fronds contain a single row of rounded leaves on each side.
The leaves have a faint citrus scent, especially when crushed.
Nephrolepis cordifolia duffi doesn’t flower. It reproduces by spores.
The spores grow on the undersides of the fronds on tiny kidney-shaped flaps of leaf tissue.
If left unattended, the spores may spread by rain and wind, allowing the plant to reproduce and grow to new areas.
Light and Temperature
- Grow nephrolepis cordifolia in partial shade and warm temperatures.
- Too much sun damages the foliage and limits growth.
- It’s recommended for outdoor growth in USDA hardiness zones 8b to 9b.
- Duffi fern can survive short periods of freezing weather, with temperatures as low as 15° degrees Fahrenheit (-9° C).
Watering and Feeding
Don’t let the soil dry out completely, the fern needs consistently moist soil.
Check the soil every couple of days. If the top of the soil feels dry, water the plant.
Use a slow-release fertilizer in the spring to encourage healthier fronds.
Spread the fertilizer pellets on the soil around the base of the plant.
Soil and Transplanting
- Use standard gardening soil with good drainage.
- Drainage is the most important factor, as duffi fern needs moist soil by not wet feet.
- If the soil is too coarse or sand-like, it may drain too quickly and not retain enough water.
- Improve water retention and drainage with peat moss and organic material.
- This also adds more nutrients to the soil.
- Transplant in the spring, giving the shallow root system time to adapt.
- Transplanting just before winter may not give the plant enough time to establish itself before colder temperatures arrive.
- This increases the risk it may die off during the winter.
Remove dead leaves to maintain appearances and promote new growth.
The plant can live for many years and dying fronds may need to be removed.
How to Propagate Lemon Button Fern
Propagate using runners or root nodules. The runners are new stems growing from rhizomes connected to the mother plant.
- The rhizomes grow underground.
- Carefully dig the soil around the runners and locate the roots.
- Trim the roots to free the young plant.
- Transplant to a new area or a container using fertile soil.
- Keep the soil moistened and follow the standard duffi fern plant care tips.
The root nodules are swollen tuber like “bulbils” appearing under the main stem of the plant.
- When new shoots appear, tubers are likely available for propagation.
- Removing the tubers requires the removal of the entire plant.
- After removing the plant, cut one of the tubers free using sharp gardening shears or scissors.
- Locate the eyes of the tuber.
- As with a potato, the eyes are small indentations where roots eventually sprout.
- Plant the cut tubers in a container of loamy soil with the eyes just below the surface.
- The narrow end of the tuber should extend above the soil.
- Keep the soil moist and the tuber should produce new roots within several weeks.
- After about eight weeks, the plants should be large enough for transplanting outdoors.
Lemon Button Fern Pest or Disease Problems
When grown outdoors, the plant may attract mealybugs, plant scale, and slugs.
- Remove slugs by hand or apply diatomaceous earth around the plant.
- Remove smaller pests with sprays of water from a garden hose.
- Treat severe infestations with insecticidal soap or Neem oil.
- Indoor plants may attract aphids and whiteflies.
- This is more common when the soil dries out or in rooms with low humidity levels.
- Keep the soil consistently moist and spritz the foliage with insecticidal soap.
Nephrolepis cordifolia has become invasive in some regions, including New Zealand and Florida.
In these areas, the lemon button fern is best cultivated as a potted houseplant.
The plant spreads easily in areas with optimal light, temperature, and water.
If grown outdoors, keep an eye on the spread of the plant and uproot new growth.
Related: Kimberly Queen fern & Emerald Fern
Suggested Nephrolepis Cordifolia Duffi Uses
The duffi fern is a popular houseplant, thanks to its unique foliage.
Grow it in a small pot in any room receiving adequate sunlight.
It’s also often used to add color to shaded areas or as an accent in rock gardens.