How To Recognize Hydrangea Diseases?

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

The beautiful hydrangea has taken root in our gardens. It is noteworthy that if these beautiful flowers are grown in open ground, then they are affected by all kinds of ailments much less often than plants growing in protected ground. However, it is also impossible to completely exclude the possibility of infection. Most often, hydrangea is affected by gray rot, powdery mildew, white sclerocial rot, tracheomycotic wilting, as well as ascochitous and septoria spots. How do you recognize their main symptoms?

White sclerocial rot

When affected by this ailment, the roots of the hydrangea first rot, as a result of which the flow of nutrients to the plants almost completely stops. Beautiful flowers stop growing and, turning brown, gradually dry out. If a harmful attack covers young plants, then the leaves and growing shoots on them will turn brown, begin to rot and abundantly cover with a cotton-like and fairly dense whitish bloom, in which, after some time, black sclerotia with irregularly shaped black sclerotia with light inner parts will form.

Powdery mildew

This attack manifests itself on young leaves of hydrangeas in the form of individual specks, covered with a cobweb powdery coating of a grayish hue. After a while, the spots begin to grow, and the plaque darkens noticeably and in some areas is often completely erased. And the infected tissues of the leaf blades are painted in reddish-brownish tones and slowly dry out in the form of rather large brownish specks. Prematurely dried leaves fall off quickly. And on a number of hydrangea varieties that are especially susceptible to this infection, growing young shoots are very strongly affected. First, tiny specks of rapidly disappearing grayish plaque form on them, and then the bark begins to necrotize, which is covered with extremely unpleasant reddish specks. The shoots are deformed rather quickly and overwinter very badly, in most cases they freeze too much.

Tracheomycotic wilting

Initially, the roots of hydrangeas are affected by the unfortunate ailment - they quickly turn brown and gradually rot. A little later, the infection also penetrates into the conducting vascular system, completely filling it with an extremely unpleasant biological mass. The influx of nutrients to the plants completely stops, and the beautiful flowers begin to wither from the upper young shoots. Subsequently, they turn yellow, and after a while they turn brown and dry out. For most leaves of adult plants, brown leaf veins are also characteristic, and on the cuts of roots and cuttings, you can almost always notice an unpleasant bloom of mycelium.

Gray rot

The stalks of hydrangeas are covered with depressed spots of a brownish color. These spots grow rather quickly. And on the leaves of plants, zonal brownish specks appear without bordering. When dry weather is established, the dead tissue of the specks cracks and gradually falls out, leaving characteristic numerous holes at the lesion sites. If heavy rainfall begins to fall, then all infected parts of plants with lightning speed will become covered with a fluffy mycelium of a smoky gray color. Spores of this mycelium will in the shortest possible time re-infect all neighboring leaves with petals.

Ascochitous spot

On the leaves of hydrangeas, rapidly growing spots of irregular shape appear, painted in yellowish-brick tones and framed with brownish thin edges. Gradually, the formation of small and convex brownish fruiting bodies of the wintering stage fungus begins in the necrotic tissues. And yellowed leaves always fall off prematurely.

Septoria spot

This ailment manifests itself in the form of countless chaotically scattered and rounded specks of dark brownish shades. All necrotic tissues brighten in the center, however, the characteristic thin brown rims do not disappear anywhere. After a while, the formation of tiny black mushroom fruit bodies begins in them. In the case of a particularly severe lesion, the spots often appear on young stalks with petioles. The defeat of the leaves significantly reduces the overall decorative effect of beautiful flowers and noticeably worsens the ripening of the shoots.