What methods are there for identifying pests and diseases of garden flowers?

Garden flowers suffer from many kinds of pests and diseases, and the control methods differ as well. In order to carry out effective control, it is especially important to detect them promptly, correctly identify and diagnose the type of pest or disease, and treat the problem accordingly. Now let's look at the methods for identifying pests and diseases of garden flowers together with the editor of Huinong Network.

(1) Seedlings wither and die, or lodge, leaving gaps and broken rows

This is usually the result of damping-off caused by fungi, oomycetes and similar organisms, or damage by underground pests such as white grubs and mole crickets.

(2) Spots of different shapes and colors appear on the leaves

There are blight spots, brown spots, yellow spots, concentric-ring spots, white spots, mold spots, sooty mold and so on, most of which are diseases caused by fungi. If the spots have a halo around them, and sometimes perforate or cause the leaf to rot, they are often caused by bacteria. Leaf-mining flies and moths can cause blight spots on the leaf surface, but there are usually slender tunnels, with excrement pellets inside the tunnels. Spots caused by sunscald or chemical injury are mostly brown or yellowish-white, and no gray mold or small black dots can be seen on the spots.

(3) Leaf deformity and abnormal color

Swelling, galls, protrusions and curling on the leaves are often formed by the damage of certain fungi, gall aphids or mites. Some viruses can also cause leaf deformity or mosaic patterns. Damage to the leaf surface by some wasps can also produce tumor-like bodies. Viral infection or the lack of certain trace elements can both cause chlorosis, yellow spots, ring patterns, mottling, net-like patterns, blotches and loss of green color on the leaf surface.

(4) A white powdery layer appears on the leaves, new shoots, floral organs and fruits

If small black dots develop within the white powdery layer later on, it is powdery mildew caused by powdery mildew fungi. As shown in Figure 2, this is a crape myrtle infected with powdery mildew, with a white powdery layer on the underside of the leaves.

(5) Leaf defects

These are often the result of damage by leaf-eating pests, while leaves damaged by sunscald, freezing injury, hail and strong wind can also become defective.

(6) Branches and shoot tips wither and die, or the whole plant withers and dies

Pests such as cicadas and branch blight can cause branches and shoot tips to wither and die; root diseases, severe rot and cankers of the trunk cortex, and nematode diseases can cause the whole plant to wither and die.

The above is the identification methods for flower pests and diseases compiled by the editor of Huinong Network. Have you all learned them?

Winter control methods for flower pests and diseases, and overwintering cold-protection techniques for garden flowers

    In winter there are generally fewer pests and diseases on flowers, but some can still appear in rooms with heating or higher temperatures, which affects both the healthy growth of the flowers and their ornamental value, so attention must be paid to pest and disease control. In ordinary households, prevention is still the main approach: maintaining suitable temperature and humidity, good indoor ventilation, and appropriate soil moisture; sterilizing the soil when sowing; and selecting vigorous seeds or introducing flower seedlings free of pests and diseases. These are all effective measures for preventing pests and diseases.
    Common diseases include powdery mildew, anthracnose, root rot, rust, root-knot disease, leaf spot, brown spot and chlorosis. Diseases can occur throughout the entire growing period of flowers, but they are most common in the high-temperature, rainy season from June to August, and a small number of pests and diseases also occur in winter.

Overwintering cold protection for garden flowers: Some families with a courtyard like to grow flowers and plants in the courtyard, but some varieties introduced from the south have poor cold tolerance, so the problem of overwintering cold protection also exists.
    Generally speaking, annual and biennial herbaceous flowers, perennial flowers and some flowering shrubs grown in the open field have strong adaptability, such as chrysanthemum, petunia, stock, red-flowered oxalis, lawn grass, tree peony, Japanese quince, Chinese rose and so on. But some flowers, such as dahlia, canna, banana shrub, banana and osmanthus, though they have a certain ability to withstand cold, cannot tolerate low temperatures. In areas north of the Yangtze River, protection still needs to be strengthened in winter to ensure that the flowers overwinter safely. The following methods are commonly used for cold protection of open-field flowers:
    Method 1: Careful management to enhance the cold resistance of the flowers themselves. When autumn arrives and the weather gradually turns cooler, the flowers enter the late growth stage. At this time, control the application of nitrogen fertilizer, apply more phosphorus and potassium fertilizer, and at the same time limit watering, so that the plants grow sturdy and their resistance to cold is enhanced. After entering the winter dormant period, one intertillage and fertilization can be carried out, applying barnyard manure, night soil or cake fertilizer and so on, to increase the concentration of the soil solution and enhance the cold resistance of open-field flowers.
    Some perennial flowers and overwintering annual herbaceous flowers, such as Chinese peony, canna, dahlia, tulip and edgeworthia, are prone to freezing injury when overwintering naturally in areas north of the Huaihe River. If a cold wave comes, materials such as fallen leaves, rice straw, straw mats or plastic film can be spread on the ground around the root zone of the flowers. This method is simple, effective and very widely used, and it can be removed after the late frost has passed.
    Method 2: Hilling up soil around the plants to prevent freezing during overwintering. Some flowers, when winter comes, have their aboveground parts entirely dormant, with only the roots still growing slowly, such as tree peony, hydrangea and cotton rose. Soil can be hilled up around the roots of the flowers to form a small mound. When the plants begin to sprout in spring, the hilled soil can be opened up.
    Method 3: Wrapping with insulation materials to protect against cold during overwintering. For some larger ornamental flowering trees, because the tree body is relatively large and cannot be buried or covered, methods such as wrapping with straw, wrapping with paper and covering with plastic film can be used for cold protection. For some flowering trees with relatively strong cold tolerance but which fear cold wind, or which have just been planted, the method of setting up a windbreak can be used, that is, building windbreaks with reed mats and other materials on the west and north sides of the flowering trees. This method is commonly used for cold protection when planting deodar cedar in areas north of the Huaihe River.

Ecological control methods for flower pests and diseases

When pests and diseases occur on flowers in the home, using chemical pesticides for control easily pollutes the environment, and improper use can also cause pesticide damage. Below are several methods for controlling pests and diseases that are easy to use at home, low in cost and low in pollution.

Plant ashMix 500 grams of plant ash with 2.5 kilograms of water, soak for a day and a night, filter out the impurities, then spray the affected plants with the clear filtrate, and it can effectively kill aphids.

Ammonia waterWhen garden flowers and trees are harmed by trunk-boring pests such as longhorn beetles, jewel beetles and carpenter moths, during the larval hatching period, before adult emergence and when larvae overwinter, inject 20 to 30 milliliters of 20% ammonia water through the upper hole of the insect tunnel, then seal it with clay or wax for 30 to 40 minutes, and the larvae or pupae can be killed.

Iodine tinctureIf the main trunk of a woody flower rots, scrape off all the rotted part down to the xylem, then apply iodine tincture, and apply it again after 7 to 10 days. This not only completely cures it, but over time, as the scar tissue on the trunk becomes prominent, it increasingly shows an aged and unusual look, with a distinctive charm.

White liquorMix white liquor and clean water at a ratio of 1:5, then apply it to the parts damaged by scale insects and aphids, once a week, and after 3 to 4 consecutive times the pests can be killed.