Flower Seed Storage Methods and Diagnosis and Treatment Techniques for Yellow Leaf Disease in Potted Flowers

Yellowing leaves on potted flowers can be caused by many reasons, and it is also a problem flower growers often encounter. If not discovered and treated in time, it can cause the flowers to die. The main reasons are as follows.

1. Yellow leaves from too much water and waterlogging: Long-term excessive water and waterlogging in the potting soil cause the flowers' roots to rot, so they cannot normally absorb water and nutrients, resulting in yellowing, falling off and death of leaves. The remedy is to stop watering and fertilizing as soon as yellow leaves are found. Loosen the potting soil and place it in a ventilated, dry place to speed up water evaporation. The watering standard is to let the potting soil dry before watering and stay moist after watering, watering thoroughly each time, and never watering lightly in scattered amounts.

2. Dry yellowing from lack of water: If the flowers lack water and the leaves droop, immediately spray water on the leaves so it is absorbed quickly. Then water the pot, taking care to water lightly so the soil is just moistened; never water too much.

3. Yellow leaves from strong light and sunscald: In summer, strong sunlight and sunscald cause yellow leaves with yellow spots (sunscald disease). Spray water promptly to cool them down and increase humidity. Add a shade net so the flowers can grow normally.

4. Yellow leaves burned by too much fertilizer: Applying too much concentrated fertilizer means the flowers cannot absorb it, the roots are burned, and they cannot absorb water, so the leaves turn yellow and fall off. In summer, apply a dilute fertilizer once a week; never apply too much concentrated fertilizer. If too much fertilizer has been applied, water more to flush the fertilizer out.

5. Thin yellow leaves from lack of fertilizer: With a lack of fertilizer, the flowers' leaves turn yellow, thin and weak, and the branches are slender, yellow and tender. Fertilizer should be applied immediately, with results seen within a week. Fertilize on schedule so the flowers grow normally and bloom more.

6. Yellow leaves soaked by too much alkali: Because potted flowers are watered over a long period, salt and alkali accumulate in the potting soil. In severe cases, an alkali crust forms on the potting soil, causing the flowers' leaves to fall off. This is especially true in the north, where both water and soil contain alkali. The method is to replace the soil or apply ferrous sulfate solution to neutralize it.

7. Yellow leaves from lack of acid: Southern flowers prefer acidic conditions, growing normally at a pH value of 6.0. If the pH value exceeds 7, the new leaves at the branch tips first turn yellow between the veins, and the edges of the old leaves wither, yellow and fall off and die. Apply ferrous sulfate once a month for normal growth.

8. Yellow leaves from too much acid: When applying ferrous sulfate, follow the stated ratio; never apply too much. If too much is applied and the leaves also turn yellow (without falling off), appropriately water with a little alkaline water to adjust it.

9. Yellow leaves from a large flower in a small pot: Because a large flower has many roots and needs more water and fertilizer, a small pot cannot meet the flower's growth needs. The old leaves are dry, yellow and lusterless, and the young leaves are yellow, thin and small. Change to a suitably sized pot, and add 30% humus to the soil so the flower grows normally.

10. Yellow leaves from cold wind: Because flowers are taken outdoors too early in spring and exposed to cold wind, or because of cold in autumn, the flowers suffer freezing damage and their leaves turn yellow. They should be brought indoors and kept moist.

11. Yellow leaves from disease: During the growth process, flowers must be constantly watched for disease prevention, with timely spraying. Common diseases include "powdery mildew," in which the undersides of leaves look powdery white, causing the leaves to wither, yellow and fall off; "brown spot," in which there are black spots on both the front and back of the leaves; and gray mold, among others. The main causes are poor light and poor ventilation.

12. Yellow leaves from insect pests: In summer, high temperatures make flowers prone to insect pests, so spraying should be done in advance for prevention. Common ones include aphids, whiteflies, red spider mites, and mites. They suck nutrients and water from the undersides of the flower leaves, causing the leaves to wither and yellow. Eliminating the pests in time allows recovery. (Source: Xingyang Municipal Forestry Bureau)