Woodwardia unigemmata

Woodwardia unigemmata, or jeweled chain fern, is an impressive plant for a number of reasons. First of all, its sheer size is stunning. Mature fronds can be 5 feet long and 18 inches wide as they gracefully arch away from the rhizome. Coupled with the scale of the fronds, the new fiddleheads unfurl with a rich red-orange color lasting more than a month, eventually turning a pleasing green. The tips of the pinnae may retain some reddish color long into summer. But wait, there’s more! A reproductive adaptation in some ferns called a bulbil, or gemma, allows plants to reproduce vegetatively rather than just by spore reproduction. Bulbils are not just found in ferns. The “head” of garlic and onions, for example, are filled with bulbils that produce plants that are genetic clones of the parent plant. The species name unigemmata literally means one gemma. In the case of Woodwardia unigemmata, the gemma is relatively large, about 1 inch in diameter in comparison to the bulbils found on species of Polystichum, which are about the size of a BB and much more prolific. The gemma grows out near the tip of the frond, and as it gets heavier, the frond arches down to the ground and gently “plants” its progeny in the ground to form a new plant.

Native populations of W. unigemmata are found in East Asia, including Vietnam, Japan, China, Nepal, the Philippines and Taiwan. It grows in rich, moist, well-drained soil in moderate shade and needs consistent water. Reliable references place jeweled chain fern in USDA Zones 7b-9b, though I’ve talked with gardeners in the Pacific Northwest whose Woodwardia unigemmata has survived 0° F with mulching. It is evergreen in all but the coldest range of its hardiness zone. For those of you in northern climates, W. unigemmata can be grown very nicely in large containers and moved in for the winter. It also makes a bold statement in a living wall as demonstrated in the Amazon Spheres in Seattle.