Athyrium niponocum pinnae banner

Plant of the Month - September 2022

Common Name: Japanese Painted Fern

GENERAL INFORMATION: 

I have always liked ferns from when I was a child and had a hidey-hole in a fern bank. I first saw Japanese Painted Ferns on an ORGS garden trip about 30+ years ago. They were quickly added to our woodland garden. Garden centres soon had choices so I looked for better colours and new named varieties. Often similar looking cultivars have different names. 

Athyrium niponocum pinnae

Athyrium niponicum var. pictum - pinnae.

Many of our plants have grown into large clumps and have been divided. Some dwindled after several years but many have hybridized and produced small plants in parts of our garden, with colours from green to burgundy-silver.

These are easy to grow, brighten up woodland beds and will survive some drought once established. It was rightly chosen 2004 Plant of the Year.

Cultivars: 

Athyrium niponicum ‘Burgundy Lace’: New fronds purple with silvery stripes, becoming more silver as they age.

Athyrium niponicum ‘Joy Ride’: Crested, larger, more blue-green. Zone 3.

Athyrium niponocum large crests

Athyrium niponocum crested

Athyrium niponicum var. pictum - Unknown Crested forms.

Athyrium niponicum ‘Lemon Cream’: Fronds with scattered with lemon-cream blotches. Zone 5.

Athyrium niponicum ‘Thrill Seeker’: Crested, lighter colour, more frilly than A. n. ‘Joy Ride’. Zone 3.

Athyrium niponicum ‘Silver Falls’: Longer arching fronds, more green-silver.

Athyrium ‘Ghost’: Silver grey, vigorous, to 75 cm tall. Found by Nancy Swell about 25 years ago. It is probably a natural hybrid of the Japanese painted fern and the European lady fern. I obtained one of her original plants.

Athyrium Ghost

Athyrium ‘Ghost’. 

Other cultivars include ‘Crested Surf’, ’Branford Beauty’, ‘Pewter Lace’, ‘Ursula’s Red’, and ‘Wildwood Twist’.

Best to look before you buy and choose the best colours.

Life Cycle: Clumping perennial Fern: herbaceous and deciduous, with slow creeping rhizomes. Will live 4-5 years or more.

Height: 15-45 cm in height, 15-35 cm wide.

Fronds: Lance-shaped, bipinnate fronds with purple to red rachises (midribs). Pinnae (leaflets) are silver grey, to purple bronze. The colour is darker at the base. The sori (sporing bodies) are half-moon to J-shaped and are on the undersides of the fronds. 

Athyrium niponocum young pinna

Athyrium niponicum var. pictum - young pinna.

Athyrium niponocum pictum sori

Athyrium niponicum var. pictum - Sori.

Range: Asia - China, Japan, Korea.

Habitat: Shady woodlands.

CULTIVATION: 

Plant: As a specimen or close together as a ground cover.

Light: Full to part shade. Best colours appear with some morning sun.

Soil: Well drained rich, moist soil, not fussy about pH.

Water: Keep moist. When established will tolerate some drought. 

USDA Hardiness: Zone 4. It needs winter cold so it is not suitable for a house plant. 

Companion planting: Other ferns, Brunnera, Heuchera, Hosta, woodland plants.

Athyrium niponocum sporeling

Athyrium niponicum var. pictum - sporeling.

Propagation:  Divide in spring. Spore-grown ferns are variable in foliage coloration and character. They germinate readily in my Toronto garden.

Sow @ 20°C. First pour boiling water over milled sphagnum moss in a pot. Cool, sprinkle with spores, then enclose pot in plastic bag. Keep at room temperature. Spores germinate within 3-6 months. NB The gametophyte (prothallus) looks like a liverwort. Fernlets, the sporophytes, appear from underneath.

Problems: Occasional slug damage. Hot sun.

References: https://www.bhg.com/gardening/plant-dictionary/perennial/

https://www.chicagobotanic.org/downloads/planteval_notes/no39_ferns.pdf

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Text and images supplied by Anna Leggatt