Origin
Athyrium alpestre (Hoppe) Milde ssp. americanum (Butters) Lellinger, commonly known as American rock-brake, is a fern species that belongs to the family Athyriaceae. It is native to North America, specifically found in the eastern parts of Canada and the United States.
Common Names
American rock-brake is also known as the Southern lady fern, the Great Basin lady fern, inland spinulose wood fern, and the mountain spleenwort. Some indigenous communities use different names for this plant, such as "bebalulch" by the Iroquois and "tsaucun tso" by the Hopi people.
Uses
Athyrium alpestre (Hoppe) Milde ssp. americanum (Butters) Lellinger has several medicinal uses in traditional medicine. Native American groups used it as a poultice or tea to treat wounds, bronchitis, and cough. Additionally, some use it to treat tuberculosis, arthritis, and fever. It is also an ornamental plant and can be used in household decoration.
General Appearance
The American rock-brake is a deciduous plant that grows up to 60 cm tall with fronds that can spread up to 45 cm wide. It has a creeping rhizome, which is the horizontal stem that runs underneath the soil. The fronds are light green and have a lanceolate shape. They are bipinnately compound, which means they have a central axis that produces secondary branches called pinnae, and these pinnae have smaller subdivisions called pinnules. The plant sporulates from July to October and produces spores that are dispersed by wind.
Overall, Athyrium alpestre (Hoppe) Milde ssp. americanum (Butters) Lellinger is a beautiful and useful fern species native to North America with an interesting history of medicinal uses.
Light Requirements
Athyrium alpestre ssp. americanum grows best in shady to partially shady locations. It requires filtered light or dappled shade to thrive. Direct sunlight can be harmful and should be avoided.
Temperature Requirements
The ideal temperature range for Athyrium alpestre ssp. americanum is between 60 to 70 degrees Fahrenheit (15.5 to 21 degrees Celsius). It can tolerate some colder temperatures, but it may not survive harsh winters or extreme heat. During the winter months, it is recommended to protect the plant from harsh frosts by covering it or bringing it indoors if possible.
Soil Requirements
For optimal growth, Athyrium alpestre ssp. americanum requires moist, well-drained soil with a slightly acidic to neutral pH range of 5.5 to 7. It prefers soil that is rich in organic matter and has good water retention capabilities. It does not tolerate waterlogged soil and may suffer if the soil is not well-draining. Adding compost or other organic matter to the soil can help improve its texture and water retention capabilities.
Cultivation
Athyrium alpestre (Hoppe) Milde ssp. americanum (Butters) Lellinger, commonly known as the American alpine lady fern, thrives best in consistently moist, well-drained soil that is rich in organic matter. The plant requires partial shade to full shade and cool, moist conditions, similar to its natural habitat in North America. It is hardy in zones 4 to 8, but it can grow in other zones with proper care.
Athyrium alpestre does well in mixed borders, rock gardens, and woodland gardens. The plant can also be grown in containers, provided the soil has sufficient moisture and drainage.
Watering Needs
Watering is an essential part of growing Athyrium alpestre. The soil around the plant should be kept consistently moist, but not waterlogged. During the growing season, water the plant regularly, especially during prolonged dry spells, to prevent the soil from drying out.
The frequency of watering may need to be adjusted according to the plant's environmental conditions, such as temperature, humidity, and exposure to sunlight. In general, the plant requires more frequent watering in warmer, drier conditions.
Fertilization
Athyrium alpestre does not require heavy fertilization. However, it benefits from occasional feeding with a balanced fertilizer, applied during the growing season. The fertilizer should be applied according to the manufacturer's instructions, and excess fertilizer should be avoided to prevent burning the plant.
Organic matter, such as compost or well-rotted manure, can be added to the soil to improve its fertility and water-holding capacity.
Pruning
Pruning is not typically required for Athyrium alpestre. However, dead or damaged fronds can be removed anytime during the growing season. The plant can also be cut back to the ground in late fall or early spring before new growth emerges.
Removing spent fronds can improve the plant's appearance and may stimulate the growth of new fronds. Deadheading is not necessary for Athyrium alpestre, as the plant does not produce flowers.
Propagation of Athyrium alpestre (Hoppe) Milde ssp. americanum (Butters) Lellinger
Athyrium alpestre (Hoppe) Milde ssp. americanum (Butters) Lellinger, commonly known as American alpine lady fern, is a deciduous fern that is native to North America. The plant is typically grown for its ornamental foliage which is bright green and feathery. Propagation of this fern can be done through spores or division.
Propagation through spores
To propagate Athyrium alpestre (Hoppe) Milde ssp. americanum (Butters) Lellinger through spores, the following steps can be followed:
- Collect spores by removing mature fronds from the parent plant and placing them in a paper bag
- Allow the fronds to dry in the paper bag for a few days until the spores are released
- Spread the spores on top of a mixture of peat moss and perlite in a seed tray
- Cover the seed tray with a clear plastic lid to maintain humidity
- Place the tray in a bright and warm location, but not in direct sunlight
- Mist the tray daily to keep the soil moist
- The spores should germinate in one to two months
- Once the ferns are large enough to be handled, transplant them into individual pots
- Allow the ferns to grow for a year before transplanting them into the garden
Propagation through division
Propagation of Athyrium alpestre (Hoppe) Milde ssp. americanum (Butters) Lellinger through division is a quicker method than propagation through spores, but it requires an established plant. The following steps can be followed:
- Select a mature plant to divide and dig it up
- Using a sharp knife, divide the plant into smaller sections making sure that each section has several fronds and some roots
- Plant each section into a pot or directly into the garden
- Water the plants well and keep them moist until established
- Divisions can be done in the early spring or fall
Disease Management
Athyrium alpestre (Hoppe) Milde ssp. americanum (Butters) Lellinger is mostly resistant to plant diseases. However, the plant may occasionally fall prey to fungal diseases such as rust, leaf spot, and Phytophthora root rot.
Rust usually appears in the form of yellowish-orange powdery spots that occur on the foliage underside. The affected leaves eventually turn yellow and die. To control rust, remove and dispose of infected plant leaves and debris. You can also apply fungicides to protect the plant leaves.
Leaf spot presents itself as circular grey or brown spots on the foliage, then progresses to cause the leaves to turn yellow or brown and wither. To prevent the spread of leaf spot, pluck and appropriately dispose of the infected leaves, and avoid watering the plant foliage overhead. You can also apply fungicide treatments as a preventative measure.
Phytophthora root rot causes root rotting and stunted growth, leading to the eventual death of the plant. To manage this disease, avoid overwatering the plant to prevent waterlogging and increase aeration around the roots by ensuring the plant soil has good drainage. Applying fungicidal treatments can also help to control the spread of Phytophthora root rot.
Pest Management
Athyrium alpestre (Hoppe) Milde ssp. americanum (Butters) Lellinger is generally resistant to pests and insects attacks. However, it may still be vulnerable to mealybugs, spider mites, and slugs.
Mealybugs and spider mites usually form colonies on the underside of the plant leaves, feeding on plant sap and causing the leaves to wither and decline. To eradicate these pests, use insecticidal sprays or dab the pests using an isopropyl alcohol-soaked cotton wool on the plant leaves' underside.
Slugs, on the other hand, mostly compete with the plant foliage for food, causing irregular holes that make the plant leaves appear unpropitious. To manage slugs, set up physical barriers or bait traps to lure them away from the plant, and handpick and dispose of them appropriately to minimize their population.
