Wednesday, June 18, 2008

Ferns: Lush and Luxurious Perennials for Shade

Ferns evoke a sense of rich mystery in the landscape, like that of a lush woodland. Their fragile appearance belies their toughness. Rather than being difficult to grow, ferns are solution plants for many of the difficult landscape problems that gardeners face. They thrive in shady, moist areas and love acid soil. Plant them around the base of trees, in dark and moist areas around the foundation of your home, behind walls or utility buildings, at the edge of wooded areas. They may grow where ever they find a foothold between cobblestones and bricks. They are great for those transitional zones between lawn and wooded areas.

Ferns prefer acid soil; ideally, the pH should test between 5.5 and 6.5. Take a soil sample to your local Cooperative Extension Office for analysis. Adjust the pH according to their expert recommendations.

If you are planting a container-grown fern, thoroughly water it before planting. Gently slip it from the pot, retaining as much of the soil as possible. Spread the roots out into the hole. Plant at the same depth as it grew in the nursery container. Water deeply with a fine spray. Too strong a stream of water can damage the foliage.

Many ferns are easily transplanted as bare root plants. These may be available as dormant crowns, mats, or plants in leaf. Dormant crowns are simply bare-root ferns in a dormant state with the dead fronds removed. Mats look like a tangle of roots about the size of a saucer or small plate. Planting them is not much different than planting container-grown ferns. The roots should be kept moist (not soggy) until planting, the soil should be properly prepared, and the plants watered well.

A few, like the Hay-Scented fern, are easily and economically propagated by bare rhizomes, or "root cuttings." These are usually about the length and diameter of a short pencil. Plant by digging a very shallow trench and laying the rhizomes in it. Or you may simply lay them atop a prepared planting bed, and cover with a couple of inches of good grade topsoil or professional potting mix. Always water well and make sure that no rhizomes are left exposed.

seldom need fertilizing. But if they look pale or grow very little, some fertilizing can help. Fish emulsion fertilizer is a favorite with fern growers.

Dilute the fish emulsion with water at a rate of 1/2 teaspoon of emulsion per quart of water. Apply as a soil drench once in Spring and again in mid-Summer.

Gardeners in the frozen north often take steps to protect their ferns during winter, even if the plants are considered to be cold-hardy. If you choose to do so, leave old fern fronds on the plants as they turn brown in the fall. A light covering of tree leaves spread over a make-do frame of sticks or poultry netting works well. The mulch and frames should be removed right away in the Spring and added to the compost pile. Take care that young fresh fronds are not broken in the process.

Here are some of my favorite ferns for the landscape:

Japanese Painted Fern (Athyrium niponicum Pictum). This is a gorgeous fern with contrasting foliage colors. New fronds are metallic gray with a reddish or purplish blush. The older fronds maintain color very well, and contrast nicely with the newer fronds. Its very cold hardy, doing well from USDA climate zones 4-9. Japanese Painted Fern grows to 10" and goes dormant in winter. Plant in partial to full shade. It is deer resistant.

Hay-Scented Fern(Dennstaedtia punctilobula). It is native to the U.S. The leaves are fragrant, as its name suggests. The deciduous, deep green fronds are triangle-shaped and heavily divided with lacy leaflets. It is very adaptable, doing quite well in poor soil, and it doesn't care whether the soil is wet or dry. As noted before, Hay-Scented Fern is propagated from rhizome cuttings that are about the size of a short pencil. Just prepare the soil, lay the rhizomes horizontally in shallow furrows, cover with soil, and water. View the instructional video below.  Very easy. Mature height is up to 30". Plant in partial to full shade in USDA climate zones 3-8. It is deer resistant.

Autumn Fern (Dryopteris erythrosora). Burgundy colored fronds emerge in spring and turn green as they mature. 'Brilliance' is one of the best. This evergreen fern prefers well-drained soil in USDA climate zones 5-8. Plant in partial to full shade. Mature height is up to 24". It is deer resistant.

Southern Shield Fern (Dryopteris ludovichiana). This evergreen native perennial has a very upright growth habit. The fronds are dark green. It tolerates dry conditions, but prefers moist soil in USDA climate zones 6-10. You can plant it in full sun to partial shade. Mature height is up to 48". It is deer resistant.

Ostrich Fern (Matteuccia struthiopteris). This native fern grows to be a whopper, up to 72". From winter dormancy, dark brown fronds emerge erect in the spring, arch outward from the center and turn dark green. Foliage is lance-shaped. This is the fern that produces that elusive delicacy so loved in the northeastern states. Plant in moist soil in partial to full shade. Though it is said to perform well in USDA climate zones 2-7, it is only marginally successful in zone 7. It is deer resistant.

Cinnamon Fern (Osmunda cinnamomea). Cinnamon fern is widely adaptable from USDA climate zones 2-10. It is native to the U.S. Emerging from dormancy, furry brown fronds unfurl and turn light green. Rust-colored spikes emerge from the center. Cinnamon fern grows to 60" Plant in moist soil in partial to full shade. It is deer resistant.

Royal Fern (Osmunda regalis). Royal fern produces bright green fronds that are mostly erect. Leaflets are broad and oblong. Rust-colored spikes emerge from the center. Royal fern often shares the same habitat as Cinnamon fern. It also requires moist soil in USDA climate zones 2-10. Plant in partial to full shade. Mature height is up to 60". It is deer resistant.

Christmas Fern (Polystichum acrostichoides). It gets its name by the fact that the tough, evergreen fronds were very popular for floral arrangements. Many people used to scour the forests to gather the dark green foliage for themselves or for commercial purposes. Christmas fern has a clump-forming habit. It prefers moist soil in USDA climate zones 3-9. Plant in partial to full shade. If it receives more sun, adequate water is essential. It is deer resistant.

Variegated East Indian Holly Fern (Arachniodes simplicior Variegata). I love plants with variegated foliage, so this one is very satisfying. Glossy, evergreen fronds have yellowish variegation along the mid-rib. It grows slowly up to 30". Plant in partial to full shade in USDA climate zones 7-11. Consistently moist soil is essential. It is deer resistant.

Japanese Holly Fern (Cyrtomium falcatum Rochfordianum). You'll see this bold, semi-evergreen fern all over the southeast. It is especially popular in parks and gardens in such classic cities as Savannah, GA and Charleston, SC. Fronds are deep green and glossy with large, holly-like leaflets. It grows to 30". Plant in partial to full shade in USDA climate zones 6-10. It requires rich, well-drained soil. Like other ferns, it is deer resistant.

Marginal Wood Fern (Dryopteris marginalis). It is also known as Eastern Wood Fern, and is native, as you might expect, to the eastern U.S. This one is evergreen, growing to 20". It performs best in USDA climate zones 2-8. Plant in shade in moist, well-drained soil. Deer resistant.

Tassel Fern (Polystichum polyblepharum). This evergreen fern has glossy, dark green fronds and fuzzy stems. Quite unusual looking. Performs best in USDA climate zones 2-8. Plant in partial shade in moist, rich soil. It grows to 24". This, too, is deer resistant.

Korean Rock Fern (Polystichum tsus-simense). This lovely evergreen fern can even double as a house plant! It has a very compact habit, growing up to 18" tall. Plant in partial shade in rich, well-drained soil. Though it prefers slightly moist soil, it will tolerated periods of dry weather. It is good for xeriscaping. If planting outdoors, it performs best in USDA climate zones 6-8. Deer resistant.

Southern Shield Fern (Thelypteris kunthii). It is a native fern that does well in sun or shade, but always requires wet or consistently moist soil. Its a great choice for planting alongside ponds, streams or bog gardens. Deciduous fronds are erect and form large, spreading clumps. Performs best in USDA climate zones 7-10. Mature height is up to 28". It should come as not surprise that this one is also deer resistant.
For more on deer resistant plants, check out my blog article on that topic.

If you would like to tell us about your experiences with ferns by adding a comment to this blog, please do. We look forward to hearing from you!
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1 comment:

Bambi Rizzoli (Nina Perini Photography) said...

Thank you for the card you sent me expressing your regrets in not having any ostrich ferns at this time (OCT), and for hoping I will remember you in the spring. I definitely will because if you could care enough to handwrite and mail a card to me, I am sure a transaction with you will be a happy one. I bet all your plants are happy too for your loving care.