River Birch (Betula Nigra) trees are deciduous trees. These trees are known for their bright white-gray bark. Once they mature, the barks peel away to give a curled appearance with salmon-red color.
The leaves of the tree grow linearly from the main and side branches. River Birch trees have five to seven trunks arising from a central point and are one of the best trees for landscaping. A healthy tree can live for at least 40 to 50 years. Once the tree is infested with pests and insects, it requires immediate care.
River Birch Tree Repair
River Birch trees are attacked by two insects, namely, Bronze Birch Borer and Birch Leafminer. The Birch Borer is a small beetle that lives on the weak branches of the tree and slowly reduces its foliage. A heavy infestation can weaken the ability of the tree to fight the Bronze Birch Borer. The Birch Leafminer reduces the aesthetic appearance of the tree by turning the leaves brown.
Bronze Birch Borer
The damage caused by the Bronze Birch Borer can be repaired by watering the tree heavily and deeply on a regular basis. Insecticides must be applied to the bark to prevent new attacks. However, this does not kill the insects already residing within the bark. The insecticides can be applied thrice during the spring and summer months.
Leafminers can be controlled by applying insecticides to prevent excess loss of leaves. This can be done in three ways:
- Foliar Spray: The spray should be applied within two to five days of the appearance of yellow spots on leaves. The spray should be applied before the spots become large brown blotches. If brown blotches appear, applying the insecticide becomes ineffectual. Watering and mulching is required to prevent further damage.
- Soil Application: Insecticides that work systemically can be applied to the soil, from where they get absorbed by the root and are transported to the leaves. The insecticide should be applied in early spring to prevent damage.
- Bole painting: Systemic insecticides can also be applied directly by painting or brushing the chemical on the tree trunk, just below the lower branches. The best time for painting is in spring before the leaf expansion starts.
Pruning the dead branches also helps repair damage and improves the appearance of the tree.
River Birch Tree Pruning
The tree should be pruned in late spring after the leaves have attained their full size. If the tree is pruned before the leaves develop, the sap bleeds, which depletes the sugar and moisture content of the tree. Late summer pruning is also not advisable as the unhealed cuts start to bleed once the sap develops. Pruning should be avoided between May and August, as fresh wounds attract the Bronze Birch Borers.
While pruning, the cut should be made at a point where the tree limb will be lost naturally at the branch collar. The cuts should be made outside the swelling in order to leave the branch collar intact. Flush cuts do not heal completely and can result in structural damage to the tree. Unhealed cuts increase the chances and rate of infestation.
It is important to mulch, water, fertilize, and prune the River Birch trees regularly. Mulching and watering makes the soil moist and cool. A River Birch tree requires constant attention and care for healthy and sustained growth.