Plant of the Month
Japanese Painted Fern
(Athyrium niponicum Pictum)
by Mike Heger, Ambergate Gardens
Interest in ferns, both native and exotic, has been building in this country for a number of years. Recent plant hunting expeditions to areas such as
China have resulted in a fair number of collections which, may in time, prove to be significant additions to the palette of ferns that perform well in northern areas of our country. If you've been reading recent trade journals and suppliers' catalogs, you undoubtedly know that the 2004 Plant-of-the-Year as selected by the Perennial Plant Association is Japanese Painted Fern, Athyrium niponicum 'Pictum'.
Japanese Painted Fern has been available in the nursery trade for many years and has proven itself as a dependable fern over a wide portion of our country. The species has green fronds and it occurs naturally in Japan, Korea and other parts of Asia. The real favored plant among gardeners is the cultivar 'Pictum', which for a long time was the only readily available, hardy variegated fern. Its nomenclature can be a bit puzzling and, even today, one can find it sold under the now outdated names of A. goeringianum 'Pictum', A. iseanum 'Pictum' or A. niponicum 'Metallicum'.
'Pictum' has graceful arching fronds that are silvery gray with purplish red petioles and veining. The color is certainly most prominent early in the season. In addition to its striking foliage color, this fern also offers excellent textural qualities. Though individual fronds can be up to two feet in length, the plant rarely stands much more than eighteen to twenty four inches tall due to the arching habit of its fronds. As we reach late summer, Japanese Painted Fern sends out a second flush of growth, which in reality are the spore producing fertile fronds. These tend to be taller and more erect than the sterile fronds and give the plant a fresh, full appearance as we enter the later portion of the growing season. This fern spreads from a creeping rhizome and, will in time, form sizable clumps in the garden. It does have great potential as a small-scale ground cover in the shady landscape.
Japanese Painted Fern is an easy plant to grow. As with most ferns, it enjoys an evenly moist, humus-rich soil and it does not have high fertility needs. Organic fertilizers are an excellent way to supply the plant's nutrient needs. This fern is ideally grown in light to medium shade but, in the far north, it can be successfully grown in higher light intensities. Foliage coloration will not be as rich or durable in full sun situations. It is important to be aware that Japanese Painted Fern can be a bit slow to emerge from the ground in spring. This fern is easily propagated by spring division of mature clumps and new plants can also be grown from spores. Keep in mind that plants grown from spores will show considerable variation in habit and coloration. On a large commercial basis, Japanese Painted Fern is often propagated by tissue culture.
There are a number of cultivar selections of Japanese Painted Fern as well as a few named crosses with other species of Athyrium. Let's look first at some of the selected cultivars. 'Burgundy Lace' has a dark burgundy spring coloration that overlays its silvery fronds. 'Pewter Lace' is of note for its metallic pewter color. 'Silver Falls' has a more intense silver coloration that intensifies as the season progresses. 'Soul Mate' is the first crested form of Japanese Painted Fern and 'Ursula's Red' has a very pronounced wine-red coloration down the center of its fronds in spring. 'Branford Beauty', 'Branford Rambler' and 'Ghost' resulted from crosses between Lady Fern, A. filix-femina and A. niponicum 'Pictum'. 'Branford Beauty' has upright silvery gray fronds with reddish petioles. A mature plant stands about two feet tall. The habit of 'Branford Rambler' is intermediate between its parents and it shows purple-red coloration on its juvenile fronds. 'Ghost' is one of the most exciting new ferns to hit the perennial marketplace. It is a sterile hybrid that stands two to three feet tall and has broad, upright, highly silvered fronds. The other hybrid of note is 'Wildwood Twist'. It is the result of a cross between the Auriculate Lady Fern, A. otophorum and A. niponicum. 'Wildwood Twist' has smoky grayish green fronds that twist as they ascend.
A wide variety of shade-loving plants make excellent companions for Japanese Painted Ferns. Among the best are:Aquilegia (Columbine), Astilbe (False Spirea) - especially the dwarf, late-blooming Simplicifolia Group, Brunnera (False Forget-Me-Not), Carex (Sedge), Dicentra (Bleeding Heart), Heuchera (Coral Bells) - especially purple-foliaged selections, Lamium (Spotted Dead Nettle), Pulmonaria (Lungwort) and Tiarella (Foamflower).