Magnolia Tree Diseases

Magnolia is one of the largest genus of flowering plants with almost 200 species and numerous hybrids. These plants belong to the family Magnoliaceae and as per archaeological evidences, some species of magnolia existed before 95 million years. These plants are considered to be one of the tough ones as they are naturally immune to most of the diseases. However, there are some diseases, that affect these trees. An insect called magnolia scale can also attack the tree and cause damage. Read on, to know more about magnolia tree diseases.

Diseases of Magnolia Trees

As mentioned above, magnolias are among some of the oldest trees on the earth. It is said that these trees possess strong immunity to resist many diseases. While, most of the magnolia tree diseases can be prevented with good care, there are some that require treatment. Let us take a look at some of the common magnolia tree diseases and treatment.

Leaf blight

Leaf blight is a common plant disease, that is caused by a type of fungus. While, established plants may not suffer much from this disease, young magnolia plants can be damaged extensively. One of the initial symptoms of leaf blight is the thread-like formation on the back side of the leaves, which develop a matted appearance with time. The leaves may stick together, as the disease spreads. Most often, pruning of the affected parts will be enough for treating this disease. Use pruning tools dipped in anti fungal preparations. Take care to prune the entire affected branches, that has to be burnt immediately. Disinfect the pruning tools after that.

Magnolia Scale

Magnolias scale (Neolecanium cornuparvum) is one of the most common pests in magnolia trees. These insects suck out the sap from the young branches of magnolia trees, that become weak. These branches may either die or produce underdeveloped leaves. Such branches are often found to be attacked by black mold. There may not be any early symptoms of scale attack and most often, it gets noticed, only when the branches turn weak and develop black sooty coating (mold). The most common treatment for this condition is to spray the branches of the tree with a mixture of horticultural oils, soap and water (during spring). It is also recommended to use chemical pesticides during late summers to curb the action of crawlers.

Leaf Spots

Like leaf blight, leaf spots is also caused by fungus. In some rare cases, some types of bacteria can also cause this magnolia tree disease. In this type of fungal infection, the leaves of magnolia trees develop small black, yellow, brown or purple-colored spots. With time, these spots get larger in size and develop white color on the center. Such leaves fall off within some time. Overhead irrigation is found to be one of the reasons for this magnolia tree disease, which is favored by the moist conditions of the foliage. In case of leaf spot disease, the affected foliage is pruned and destroyed. You may also cut the intertwining branches so as to arrest the spread of this disease. It will be better to spray fungicides on young magnolias to prevent this condition.

Now, you have a basic idea about some of the common magnolia tree diseases. Apart from the above said conditions, another fungal disease called verticillium wilt can also occur in magnolias. In this case, the fungus lives in the soil, where the tree is planted. The leaves and branches of the tree start wilting and eventually die. The only solution is to dig out the tree with roots and destroy it. You should not plant another magnolia tree in that location. Before digging the tree out, try some nitrogen-rich fertilizer. If it does not work, dig out the tree. In short, check for the symptoms to identify the disease. Timely treatment is required to save your magnolia tree from damage. Above all, take all precautionary measures to prevent the occurrence of these diseases.