Photo copyright © 2021 Mariposa Native Plants
A small native fern in the polypody family, Nested Polypody is an interesting plant that emerges in mid-winter in the Sierra foothills. It provides some cold season greenery, and it is a refreshing plant to find on a hillside when everything else is dormant and brown. As the landscape begins to dry out in the summer, this fern tends to go dormant. It is a natural hybrid of two other native California ferns, the California Polypody (Polypodium californicum) and the Licorice Fern (Polypodium glycyrrhiza).
A close-up of P.calirhiza in mid-winter, Sierra foothills, with fresh green leaves. These ferns prefer rocky ledges and slopes, tend to be found in shadier locations, and they make a good plant for stabilizing embankments. Photo copyright © 2021 Mariposa Native Plants.
P.calirhiza is found all along the Pacific coast from the Oregon border south to as far as Santa Maria. Nested Polypody also grows on the western slope of the Sierra Nevada from Redding south to the foothills east of Visalia. In Mariposa County, it's common in the foothills, the lower mountains, and the Merced River canyon leading into Yosemite Valley. Elevation: sea level to 7,500 ft. (2300m). Sun: partial. Temperature: cold tolerant to 15°F (-10°C). Soil: rocky or loamy soil, preferably partly shaded, sloped ground; ferns prefer a soil that is slightly acidic with a pH from 4.5 to 7.
Fairly easy to care for once established. Needs a site that has moderate moisture, and partial shade, such as the understory of oak trees. P.calirhiza is especially happy on slopes, embankments, and rocky ledges. The best time to plant from the container is in the months of January or February for Mariposa and surrounding counties. If rains are infrequent after planting, give the plant 1 gallon (4 liters) of water every week. Roots are sensitive to disturbance; avoid breaking the root ball when planting from the container. Nested Polypody is summer dormant; it will turn brown and appear to die off during the hot months. But it is a perennial plant, and it will come back after some soaking winter rains arrive. It spreads, albeit slowly, primarily by underground rhizomes.
Foothills (to 2500 feet), lower mountains (2500-3500 feet), and middle mountains (3500-6000 feet).
A small patch of P.calirhiza in early January, Sierra foothills, in the shade of Interior Live Oaks and a large Deer Brush shrub. Nested Polypody spreads through underground rhizomes, and this is evidently the means by which this group of plants arose. Photo copyright © 2021 Mariposa Native Plants.
Ferns are deer resistant. Generally, plants that are deer resistant are also gopher resistant. Where we here at Mariposa Native Plants find abundant patches of Nested Polypody (Mariposa County foothills), there are also large gopher populations. So, it does not seem like these native California ferns are particulary susceptible to having their roots eaten by pocket gophers. Indeed, the native California fern from which P.calirhiza has hybridized, California Polypody, is gopher resistant. You probably do not need to place a gopher cage into the hole where the plant will be located.
No significant plant pathogens affect species in the Polypodium genus.
Where the plant receives adequate shade and has access to summer moisture--such as a streambank or a wetter, well-shaded arroyo--Nested Polypody may persist green throughout most of the hotter months.
#1 container, about 1 gallon; winter, spring, and early summer.