Texas is a land of contrasts, with high, windy plateaus, mountain ranges, hot deserts, wooded hills and sandy Gulf Coast areas. Much of that seems inhospitable to moisture-loving ferns, yet Texas has 127 native fern species, more than any other state in the continental U.S. In addition, Texas gardeners grow exotic ferns from other places, so there's a range of fern choices you can consider based on your gardening conditions.
For an area that stays consistently moist, royal fern (Osmunda regalis), which grows in U.S. Department of Agriculture plant hardiness zones 4 through 9, grows 3 to 6 feet tall and 3 feet wide. Its long fronds have broad, coarse leaflets and die back in winter. Royal fern prefers acidic soil rich in organic matter, such as pool edges, streams and water gardens. It grows either in partial shade or, if kept wet, sun. It's native to most continents and grows wild in Texas. Another moisture-loving fern, but with a more delicate appearance, maidenhair fern (Adiantum capillus-veneris, USDA zones 5 through 8) grows in a variety of Texas habitats, including bogs, streams, and wet areas. Wiry, arching stems have groups of fan-shaped leaflets. It grows 9 to 18 inches tall and wide, preferring partial to full shade.
Some ferns can withstand a certain amount of drought, even though they may also be able to grow in moist conditions. Such is the case with Southern maiden fern (Thelypteris kunthii, USDA zones 7 through 11), also called wood fern or shield fern. It tolerates clay soils and summer droughts fairly well, especially if in shade. It can spread quickly and grows about 3 feet tall and wide. It's native to Texas Hill Country and much of the South. Even tougher is hairy lip fern (Cheilanthes lanosa, USDA zones 5 through 9), which can withstand extended drought once it's established. Plant it between rocks where roots can be shaded and the soil retains moisture. The soil must be well-draining. Its fronds are 8 to 15 inches long, with plants 8 inches tall and wide.
Ferns for Shady Areas
If you have an area of dense shade, such as under trees or on the north side of a house, it's often difficult to find plants that tolerate those conditions. Suitable for low-light situations, tassel fern (Polystichum polyblepharum, USDA zones 5 through 8) has dark green, finely divided, evergreen fronds that form a clump 2 feed wide and tall. In spring, the ends of uncurling fronds flip over to resemble a tassel before the frond fully unfurls. Another evergreen fern that needs shade, Christmas fern (Polystichum acrostichoides, USDA zones 3 through 8) is native to the southeast, including Texas. It's still green at Christmas, which is how it got its name. Its deep green, feathery fronds are upright in summer but lie flat in winter. It grows 1 to 3 feet wide and tall.
Not all ferns have green fronds. Some are colorful, such as Japanese painted fern (Athyrium niponicum "Pictum," USDA zones 5 through 8), widely planted for its foliage. Gray-green, silvery leaflets, sometimes with burgundy hues, attach to a red stem. The deciduous fern is 8 to 12 inches tall and wide, preferring shade to partial shade and moist conditions. Bringing bright tones into gardens, autumn fern (Dryopteris erythrosora, USDA zones 5 through 11) has feathery fronds that show pinkish-coppery color in spring. Suitable as a ground cover, it grows 18 to 24 inches tall and 18 inches wide. Autumn fern prefers shade and moist soil.
Some ferns spread by forming plantlets around the mother plant to create a clump. Others spread by sending out creeping rhizomes from the roots that travel underground and start up new plants at a distance from the parent. Japanese creeping fern (Lygodium japonicum, USDA zones 7a through 10b) sends out rhizomes and grows wiry vines up to 90 feet long, capable of smothering nearby plants. Avoid planting this fern in Texas, as it becomes invasive. Japanese holly fern (Cyrtomium falcatum, USDA zones 6 through 11) can also become invasive if it spreads into natural habitats. Dig out plants and cut off fronds before they form spores.