How to Grow Outdoor Ferns in Your Garden
Written by MasterClass
Last updated: Jun 7, 2021 • 5 min read
Whether you plant them in a hanging basket or grow them as a groundcover, ferns bring tropical ambiance to any home shade garden. As long as you have a moist and shady environment, ferns provide an easy way to spruce up your garden with layers of green texture.
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6 Types of Ferns That Are Ideal for Outdoor Gardens
There are numerous species of fern plants that will thrive outdoors in your garden with minimal effort.
- 1. Christmas fern: Polystichum acrostichoides is an evergreen ornamental fern with leathery, dark green fronds that are two to three feet long. Its fronds resemble the needled leaves of a pine tree, which is how it gets its name. Christmas fern is easy to grow in a wide range of environments, though full shade or partial shade are ideal.
- 2. Boston fern: Also known as sword fern, Nephrolepis exaltata is an evergreen perennial herbaceous plant. The arching branches of this tropical fern make it ideal for placement in a hanging basket. Although often grown indoors as a houseplant, Boston ferns flourish outdoors in the right conditions. Boston ferns require a cool environment with partial shade or full shade, as their fern fronds are easily scorched in direct sun. Boston fern cultivars ideal for outdoor growing include Tiger Fern (Nephrolepis exaltata ‘Tiger Fern’) and Lemon Buttons (Nephrolepis cordifolia 'Lemon Buttons').
- 3. Lady fern: One of the more low-maintenance ferns due to its tolerance to sunlight, Athyrium filix-femina has lush bright green foliage with frond stalks in various shades of purple, red, and green. This perennial fern grows two to five feet tall, depending on the type, and while it prefers moist soil, it becomes increasingly drought-tolerant as it matures. Its rhizomes and emerging fronds are poisonous when raw, so avoid planting lady fern if you have an outdoor pet. Cultivars that are good for outdoor growing include the Japanese painted fern (Athyrium niponicum pictum), Lady in Red (Athyrium filix-femina 'Lady In Red'), Silver Falls Japanese painted fern (Athyrium niponicum 'Silver Falls'), and ostrich fern (Matteuccia struthiopteris).
- 4. Maidenhair fern: Featuring dark stripes and bright green, delicate fronds, maidenhair ferns require a humid climate and moist soil rich in organic matter. They're extremely sensitive to direct sunlight and should only be planted in full shade locations. Types of maidenhair ferns suitable for outdoor growing include the American maidenhair (Adiantum pedatum), northern maidenhair (Adiantum pedatum aleuticum), and southern maidenhair (Adiantum capillus-veneris).
- 5. Osmunda fern: One of the tallest varieties of ferns available to home gardeners, osmunda ferns thrive in moist, shady, swamp-like areas such as the Ozark region in Missouri. Types of Osmunda ferns recommended for outdoor growing include the cinnamon fern (Osmunda cinnamomea) and interrupted fern (Osmunda claytoniana).
- 6. Wood fern: One of the most adaptable varieties of fern due to its tolerance of various light conditions (full shade to indirect light), this medium-sized hardy fern is also drought-tolerant once mature, which makes it a great choice for first-time fern growers. Types of wood ferns ideal for outdoor growing include the autumn fern (Dryopteris erythrosora), crested buckler-fern (Dryopteris cristata), leatherleaf fern (Rumohra adiantiformis), and marginal wood fern (Dryopteris marginalis).
How to Plant Outdoor Ferns
Most varieties of ferns share the same planting requirements, but there are some types that only thrive in certain climates or light conditions. Use these instructions as guidelines, but make sure you look up the planting requirements and suitable USDA hardiness zones for your specific type of fern.
- 1. Choose a planting time based on your climate zone. Typically, the best time to plant ferns is in early spring after the last frost, but you can also plant during the summer without much trouble. In temperate climates, you can even plant ferns all year round.
- 2. Choose a shady location. The majority of ferns thrive in partial to full shade conditions. If your specific species of fern does happen to tolerate partial sun, make sure it gets extra water to compensate for the heat.
- 3. Plant ferns in moist, slightly acidic soil. In their natural environment, most ferns grow in humid forests or on the bank of a water source, so they generally require very moist soil. Even fern varieties that become drought tolerant as they mature usually require moist soil at planting time.
- 4. Enrich your soil with organic compost. Spread a few inches of organic compost on the soil surface and use a gardening tool to mix it eight to 10 inches deep. Rich soil with will help jumpstart your fern's growth.
- 5. Plant your ferns. Dig a hole as deep as the fern's rootball and twice as wide. Gently remove your young fern from its pot, being careful not to disturb its root system, and place it in the planting hole. Fill the hole with soil. Space ferns at least two feet apart from each other.
- 6. Spread a two-inch layer of mulch over your soil. Organic mulch, such as pine bark or leaf mold, will lock moisture into the soil, keep the temperature cool, and suppress weed growth.
How to Grow and Care for Outdoor Ferns
Most ferns are relatively easy to maintain, but if you run into any issues, these growing tips will help you keep your ferns healthy.
- Water ferns regularly to avoid dry soil. You never want sopping wet soil, but consistently keeping the top five inches of your soil moist is the key to a healthy fern. If natural rainfall isn't doing the job, make sure you provide your fern with sufficient water during its growing season.
- Fertilize as needed. Many ferns don't require fertilizer, but if you're not seeing the desired amount of new growth, you can try using a slow-release fertilizer in the spring.
- Monitor for pests. Ferns aren't bothered much by pests in comparison to most other plants, but slugs may damage fern fronds. To deter slugs, try creating a barrier around your ferns using crushed eggshells or diatomaceous earth.
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