Overview
Dryopteris submarginalis (Langsd. & Fisch.) C. Christens. is a fern species that belongs to the Dryopteridaceae family. This plant is commonly known as the Coastal Wood Fern or Marginal Shield Fern.
Origin
Dryopteris submarginalis is a native fern species in North America. You can find it on the east coast of the United States and Canada, where it grows in moist or wet forests, rocky stream banks, and on mossy rocks.
General Appearance
Dryopteris submarginalis grows in a clumping habit, where it can reach up to 100 cm (39 inches) in height and 60 cm (24 inches) in width. The fronds are leathery, glossy, and can grow up to 80 cm (31 inches) in length and 20 cm (8 inches) in width. The leaf color is bright green, and the texture is bipinnate, which means that the leaves are divided into secondary leaflets. The underside of the leaflets has a few scattered scales and sori.
Uses
Dryopteris submarginalis is commonly used in landscaping as a groundcover or as a low-maintenance accent plant in naturalistic or woodland gardens. The plant prefers shade to partial shade and thrives in moist, well-drained soils. Because of its leathery texture and glossy foliage, it is resistant to rabbit and deer browsing.
Growth conditions for Dryopteris submarginalis
Light: Dryopteris submarginalis thrives in partial to full shade. It prefers indirect sunlight or dappled shade to direct sunlight. When grown under bright light conditions, the leaves may scorch or wilt due to excessive transpiration.
Temperature: The optimum temperature range for growing Dryopteris submarginalis is between 15°C and 25°C. Lower temperatures can prolong dormancy periods, while high temperatures can lead to wilting or yellowing of leaves. The plant can tolerate occasional frosts but is not frost hardy.
Soil: Dryopteris submarginalis prefers moist, fertile, well-drained soils with a pH range between 5.0 and 7.5. The soil should be rich in organic matter and have good water-holding capacity without being waterlogged. Sandy or clay soils with poor drainage should be amended with organic matter prior to planting.
Water: For optimal growth, the plant requires consistent soil moisture. The soil should be kept moist but not wet. Overwatering can lead to root rot, while under watering can cause wilting and yellowing of leaves. The plant can tolerate periods of drought, but prolonged dry periods can lead to stunted growth or death.
Fertilizer: Dryopteris submarginalis benefits from regular fertilization during the growing season. A balanced fertilizer with equal amounts of nitrogen, phosphorus, and potassium can be applied in early spring and mid-summer. Alternatively, slow-release fertilizers can be added to the soil during planting.
Humidity: Dryopteris submarginalis prefers moderate to high humidity levels. In dry indoor environments, it may benefit from misting or a humidifier to increase moisture levels. Outdoors, the plant can benefit from surrounding plants that offer shade and increase humidity levels.
By providing the appropriate growth conditions, Dryopteris submarginalis can thrive and add a lush and unique foliage display to any garden or indoor space.
Cultivation
Dryopteris submarginalis is a well-known fern that grows in damp places. It is adaptative and can thrive in various climatic conditions. It prefers partly shaded areas with moist, moderately acidic, and rich soil. The plant is propagated by spores, which are sown on a mixture of sphagnum moss and perlite. It is recommended to keep the spore tray in a warm and humid place until the spores start to germinate, usually after two to three weeks.
Watering Needs
Dryopteris submarginalis thrives well when the soil is moist but not waterlogged. The plant thrives in areas with consistent moisture, and it is advisable to water the plant weekly or whenever the topsoil dries out. During the hot months of the year, it may require more watering to prevent the soil from drying out. Overwatering can lead to root rot and fungal diseases, which can be destructive to the plant.
Fertilization
Dryopteris submarginalis thrives in nutrient-rich soil. However, providing the fern with too much fertilizer can lead to leaf scorch or even kill the plant. It is advisable to use slow-release fertilizers that release nutrients over an extended period. The best time to fertilize the plant is during the growing season to promote healthy and vigorous growth.
Pruning
Dryopteris submarginalis is a low-maintenance plant that requires minimal pruning. However, regular removal of dead or yellowing fronds can foster new growth. Dead fronds can be cut off at their base with sharp pruning shears or scissors. Overcrowded areas can be thinned out to prevent fungal diseases and pest infestation.
Propagation of Dryopteris submarginalis
Dryopteris submarginalis, also known as woodland shield fern, is a fern species that can be found in North America. Propagation of this plant can be achieved through various methods such as spores, division, and tissue culture.
Propagation by spores
Spore propagation is a common method for propagating ferns. To propagate Dryopteris submarginalis using spores, you need to wait until the spores mature, which typically happens in the fall. Harvest the mature spores by cutting the fronds and placing them in a paper bag to allow the spores to dry and be collected. Sow the spores on a surface moistened with distilled water and sterilized beforehand. Cover the surface with a clear plastic wrap to maintain high humidity levels. Keep the tray in a bright, warm, and humid location, and after some time, you should see little ferns beginning to form.
Propagation by division
Division involves separating an established plant into two or more parts and transplanting them into individual containers. To propagate Dryopteris submarginalis through division, carefully dig out the plant and separate the rhizomes, ensuring each piece has a growing point. Replant the separated rhizomes into individual containers filled with well-draining soil. Water the newly transplanted ferns and keep them in a shady location until they are established.
Propagation by tissue culture
Tissue culture is a modern method of propagating plants that involves the growth of plant cells or tissues in a sterile environment. To propagate Dryopteris submarginalis by tissue culture, take a small part of the plant, usually a leaf, and sterilize it by treating it with bleach and ethanol. Place the sterilized plant tissue in a culture medium containing nutrients and plant hormones. Keep the tissue in a sterile environment at a specific temperature, light, and humidity level. Once the plant tissue has grown sufficiently, it can be transplanted into soil or directly into a container.
Disease Management
Several diseases can affect Dryopteris submarginalis, including:
- Rust: This disease causes the leaves to develop small yellow to orange spots. Over time, these spots can enlarge and/or merge, forming large, irregular rusty patches. Rust can be managed by removing infected leaves and improving air circulation around the plant.
- Bacterial soft rot: This disease causes the crowns of the plant to become soft and mushy. If left unchecked, the entire plant can rot and die. The best way to manage bacterial soft rot is by removing infected plants and not planting new ferns in the same location.
- Leaf spots: Various fungi can cause brown, black, or grayish spots to develop on the fronds. Infected leaves should be removed and destroyed, and the ferns should be kept free of debris and given adequate spacing to promote good air circulation.
Pest Management
Dryopteris submarginalis is relatively pest-free, but there are a few pests that may pose a problem:
- Spider mites: These tiny pests feed on the underside of the leaves, causing yellow spots to develop on the upper surface. Infestations can be controlled by spraying the ferns with a strong jet of water or with insecticidal soap.
- Slugs and snails: These mollusks can eat large holes in the fronds of the ferns. They can be managed by handpicking, using traps such as beer traps, or by applying a slug and snail bait.
- Deer: These herbivores will readily graze on ferns. The best way to manage deer is by using fences or repellents.
