Origin
Alnus serrulata (Ait.) Willd. var. subelliptica Fern. is a species of tree that is native to North America, specifically in the eastern and southeastern regions of the United States. It can be found in various habitats such as streambanks, wetlands, and floodplains.
Common names
The tree is commonly known as hazel alder, smooth alder, tag alder, or brookside alder.
Uses
The hazel alder has various uses, including erosion control, habitat restoration, and ornamental purposes. As it is a fast-growing tree, it can quickly establish a root system that helps prevent soil erosion in wetland areas. Additionally, its branches and leaves provide shelter and food for various wildlife species such as birds, deer, beavers, and rabbits. Some people also grow this tree for its ornamental value as it produces a dense canopy that can serve as a shade tree or provide privacy.
General appearance
The hazel alder has a shrubby growth habit, typically growing up to 12 to 20 feet tall and 6 to 10 feet wide. Its bark is gray-brown and smooth when young, but it becomes rough and fissured as it ages. The leaves are alternate, simple, and oval-shaped, with serrated margins and a green color. In the spring, the tree produces small drooping catkins that are reddish-yellow and later turn into small cone-shaped fruits. The hazel alder's branches are typically thin and flexible, allowing them to sway in the wind.
Light Requirements
Alnus serrulata var. subelliptica Fern. prefers full sun to partial shade. In full sun, it will grow faster and have denser foliage. However, it can also tolerate some shade, especially in hot climates, as long as it still receives at least 4 hours of direct sunlight per day.
Temperature Requirements
This plant is native to the southeastern United States and can tolerate a range of temperatures. It is hardy to USDA zones 6-9, which means it can withstand minimum temperatures as low as -10°F (-23°C). It prefers mild temperatures between 60-80°F (16-27°C) but can tolerate temperatures as high as 100°F (38°C) if it receives enough water.
Soil Requirements
Alnus serrulata var. subelliptica Fern. prefers moist, well-draining soils that are slightly acidic to neutral (pH 5.0-7.5). It grows best in soils with high organic matter content and can tolerate occasional flooding. It can also tolerate some drought once it is established, but it will grow best if it receives consistent moisture.
Cultivation of Alnus serrulata (Ait.) Willd. var. subelliptica Fern.
Alnus serrulata (Ait.) Willd. var. subelliptica Fern. is a deciduous tree that requires well-draining soil for optimal growth. It grows well in full sun to partial shade and is best suited for USDA hardiness zones 5-8.
When planting, dig a hole that is two times the size of the root ball and mix in compost or other organic matter to improve soil quality. Place the tree in the hole and backfill with soil, making sure to tamp down the soil to remove any air pockets.
Watering Needs
Alnus serrulata (Ait.) Willd. var. subelliptica Fern. requires regular watering, especially during its first year of growth. Water deeply once a week to ensure that the soil is moist but not waterlogged. Reduce watering during the winter months when the tree is dormant.
It is important to note that overwatering can cause root rot and other diseases, so be sure to monitor the soil moisture level and adjust your watering schedule accordingly.
Fertilization
Alnus serrulata (Ait.) Willd. var. subelliptica Fern. benefits from regular fertilization to ensure healthy growth. Apply a balanced fertilizer in early spring before new growth appears and again in late spring or early summer. Be sure to follow the manufacturer's instructions regarding the amount and frequency of application.
It is important to avoid excessive fertilization, as this can harm the tree and lead to nutrient imbalances. Always use a slow-release fertilizer, as this will provide a steady supply of nutrients over time.
Pruning
Pruning Alnus serrulata (Ait.) Willd. var. subelliptica Fern. is necessary to maintain its shape and promote healthy growth. Prune in late winter or early spring before new growth appears.
Remove any dead, damaged, or diseased branches, as well as any crossing branches that may rub against each other and cause wounds. Cut back any overly long or leggy branches to promote a more compact shape.
It is important to use clean, sharp pruning tools to minimize the risk of infection. After pruning, be sure to sanitize your tools with rubbing alcohol or another disinfectant to prevent the spread of disease.
Propagation of Alnus serrulata (Ait.) Willd. var. subelliptica Fern.
Alnus serrulata (Ait.) Willd. var. subelliptica Fern., also known as smooth alder or hazel alder, can be propagated by several methods, including seed propagation, cutting propagation, and layering propagation.
Seed propagation
The most common method of propagating Alnus serrulata var. subelliptica is through seed propagation. Seeds can be collected from mature trees in the fall and should be sown in the spring. The seeds should be stratified for 60 to 90 days prior to sowing in a mixture of sand and peat moss. The seeds should be watered regularly, and germination should occur in 10 to 14 days.
Cutting propagation
Cutting propagation can also be used to propagate Alnus serrulata var. subelliptica. Semi-hardwood cuttings should be taken in early summer, and the leaves should be removed from the lower half of the cutting. The cuttings should be treated with rooting hormone and inserted into a rooting medium of perlite and peat moss. The cuttings should be kept moist and in a warm, humid environment until roots develop in 3 to 4 weeks.
Layering propagation
Layering propagation is another method of propagating Alnus serrulata var. subelliptica. In the spring, a low branch of the tree can be selected and a shallow cut can be made on the underside of the branch. The wounded area should be treated with rooting hormone and covered with soil. The branch should be secured to the soil with a U-shaped stake. Roots should develop in a few months, and the rooted branch can be removed from the parent plant and planted in a new location.
Disease and Pest Management for Alnus serrulata (Ait.) Willd. var. subelliptica Fern.
Alnus serrulata (Ait.) Willd. var. subelliptica Fern., commonly known as hazel alder, is a deciduous shrub that belongs to the Betulaceae family. Although it is a relatively hardy and disease-resistant plant, it is still susceptible to a few diseases and pests that can weaken or even kill it.
Common Diseases
The most common diseases that affect Alnus serrulata are:
- Phytophthora root rot: This is a fungal disease that attacks the roots of the plant and can cause severe damage, including death. Symptoms of this disease include yellowing of the leaves, wilting, and stunted growth. To manage phytophthora root rot, it is essential to avoid overwatering the plant and ensure good drainage. Fungicides may also be used, but they should be applied early in the disease's onset.
- Rust: Rust is a fungal disease that can attack Alnus serrulata during humid weather conditions. The symptoms of this disease include yellowing of the leaves, black spots, and powdery growth on the lower surfaces of the leaves. To manage rust, it is advisable to prune and destroy affected branches or leaves and apply a fungicide to prevent the spread of the disease.
- Canker: Canker is a fungal disease that can attack the bark of the Alnus serrulata, causing it to crack and eventually die. Symptoms of canker include sunken or discolored patches on the bark and oozing sap. To manage canker, it is advisable to prune the affected branches and apply a fungicide to prevent the disease's spread.
Common Pests
The most common pests that affect Alnus serrulata are:
- Alder flea beetle: These are small, black beetles that feed on the leaves of the Alnus serrulata, causing them to become skeletonized. To manage these pests, it may be helpful to spray the plant with insecticidal soap or neem oil.
- Alder leaf beetle: Similar to the flea beetle, the alder leaf beetle also feeds on the leaves of the Alnus serrulata, causing brown patches and holes. To manage these pests, it is advisable to prune and destroy affected branches or leaves and spray the plant with insecticidal soap or neem oil.
- Spider mites: These are tiny pests that can cause damage to the Alnus serrulata by feeding on the leaves. Symptoms of spider mites infestation include yellowing of the leaves and the presence of webbing. To manage spider mites, it may be helpful to spray the plant with insecticidal soap or neem oil.
It is essential to monitor the Alnus serrulata regularly for any signs of disease or pest infestation, especially during the growing season. Maintaining good cultural practices, such as proper watering, fertilization, and pruning, can also help prevent disease and pest problems. If in doubt, seek the advice of a professional horticulturist or arborist for proper management of the plant.
