What to do if the leaves of Cognac jasminoides turn yellow

During the growth process, the leaves of Gardenia often turn yellow, and the reason is mostly due to improper cultivation and management. Too much or too little water, too much or too little sunlight, too much or too little fertilizer will cause the leaves to turn yellow, but the yellowing situation is different, and the reasons should be carefully observed and analyzed to correct them.

Water yellow: The young leaves are dark yellow and dull, the old leaves have no obvious changes, the branches are small and yellow-green, and the new shoots shrink and do not grow, indicating excessive watering. Remove the flowers from their pots and place them in a ventilated, cool place where the soil will dry and then put them back into the pots.

Drought yellow, water-deficient yellow is different from water-rich yellow. Water-deficient yellow means that the leaf tips or edges become dry and dry. The old leaves wither and turn yellow and fall off from bottom to top, but the new leaves grow more slowly. normal. Pay attention to watering enough and thoroughly.

Scorching yellow: Strong sunlight shining directly on some shade-loving flowers (such as spider plants, hostas, etc.) can easily cause the leaf tips and leaf edges of the flowers to wither, and yellow spots to appear on the sunny parts of the leaves. Just move it to a shaded place.

Light-deficiency yellow: If the leaves are placed in a shaded environment for a long time, the leaves will not receive enough sunlight and cannot form chlorophyll. The entire leaves will turn yellow and then fall off. This disease can be avoided by supplementing the light.

Fat yellowing: yellowing of flowers caused by excessive fertilization or excessive concentration, which is manifested in the appearance of dry brown at the tips of new leaves. Generally, the leaves are thick and dull, and the unevenness is not stretched, and the old leaves are brown and fall off. Fertilization should be stopped immediately, and part of the fertilizer should be rinsed with a large amount of water if necessary.

Fat-deficiency yellow is manifested in that the young leaves become lighter in color and appear yellow or light green, while the old leaves are relatively normal or gradually turn from green to yellow. Check the pot soil. If it is dry, replace the soil. Apply thin fertilizer frequently and pour some alum water in a timely manner.

Cultivation of Gardenia

1. Soil: Gardenia is an indicator plant of acidic soil, so the slightly acidic environment of the soil is the key to determining the growth of gardenia. . The culture soil should be a mixture of 70% slightly acidic sandy red soil and 30% leaf humus. It is appropriate to control the soil pH value between 4.0-6.5.

2. Temperature: The optimal growth temperature of gardenia is 16℃-18℃. Low temperature and direct sunlight are extremely detrimental to its growth. Therefore, in summer, gardenias should be maintained under a sparse forest or shade shed with good ventilation, high air humidity and light transmission. In winter, put it in an environment where it can see sunlight and the temperature is not lower than 0℃, and let it sleep. Too high temperature will affect the flowering in the next year.

3. Water: Gardenia likes moist air, so watering should be increased appropriately during the growth period. Usually when the potting soil turns white, water it thoroughly. Summer is hot and dry, so spray the leaves 2-3 times a day to increase air humidity and help the plants cool down. But after the flowers appear buds, watering should not be too much to avoid causing buds to fall off. It is better to water on the dry side in winter to prevent water damage and root rot.

4. Fertilizer: Gardenia is a plant that likes fertilizer. In order to meet its demand for fertilizer during the growth period and maintain a slightly acidic environment in the soil, ferrous sulfate can be mixed into the fertilizer solution in advance. Fermentation. After entering the peak growth season in April, topdressing can be done every half month (it is best to add more water when fertilizing to prevent burning of flowers). This can not only meet the gardenia's demand for fertilizer, but also keep the soil environment in a relatively balanced slightly acidic environment to prevent the occurrence of yellowing disease. harm.

5. Propagation: Although there are many ways to propagate gardenias, the easiest and fastest is the floating water planting method. First, find a foam board, drill holes in it, and place the gardenias Cut off the half-ripe branches of the current year and insert them into the holes of the foam board. Then put the foam board into a bucket filled with water. Place the bucket in an environment that can both shade the driftwood strips and allow sunlight to shine on the bucket. If the water temperature is controlled between 18°C ??and 25°C, gardenias can grow roots of more than 3 cm in one week. This method is used to cut gardenias, and the survival rate is 100%.

What to do if Cognac japonica does not form buds?

(1) Improper water and fertilizer. During the growth period of gardenia, excessive water and fertilizer will cause leggy branches. Nutrients are mostly used for the growth of vegetative organs (roots, stems, leaves). The reproductive organs (flowers or seeds) lack nutrients, which affects the formation of flower buds, resulting in no or very slow flowering. If it is too small, even if it can bloom, it will easily fall off the flowers and buds. This phenomenon often occurs when too much nitrogen fertilizer is applied and there is a lack of phosphorus fertilizer. Due to insufficient phosphorus fertilizer, the formation of flower buds will be affected. Therefore, during the flower bud differentiation period, attention should be paid to adding flower fertilizer containing more phosphorus fertilizer or 0.2% potassium dihydrogen phosphate solution, which is beneficial to the formation of flower buds and bud pregnancy. Fertilizing too much during the budding period and watering too much or too little can easily cause flowers and buds to drop. During the flower growth period, lack of fertilizer and water will result in poor plant growth, thinness and short stature. It can also easily cause few blooms or small flowers with poor flower quality.

(2) The lighting temperature is not suitable. (Gardenia prefers semi-shade in summer and full sun indoors in winter.) Due to the different origins of flowers, their ecologies are different. Some prefer light and some prefer semi-shade; some prefer warmth, some prefer coolness, and some They like warmth and moisture, and some are drought-tolerant. If their respective living conditions are not met, it will easily cause flower and bud drop.

(3) The soil contains high salinity and alkali content. Gardenia likes slightly acidic environment but is afraid of salt and alkali. Even flowers that are more tolerant to salt-alkali, such as geraniums, roses, etc., will affect their growth, development and flowering when the soil salt content exceeds 0.1% and the pH exceeds pH7.5. This is because the soil has the best nutrient availability under the slightly acidic pH range of 6-7, so it is most suitable for the growth and development of flowers.

Acidic soil doesn't just affect flowering. In severe cases, plants may die.

(4) Years for pruning. If cultivated gardenias are not pruned and reshaped for a long time, the branches will be messy, which will not only affect the appearance, but also consume a lot of nutrients due to many unnecessary branches, affecting the formation of flower buds, which is also one of the reasons for no flowering or little flowering.

(5) The room temperature is too high in winter. Gardenia is dormant or semi-dormant in winter, and the optimal room temperature is about 5 degrees. Even for some flowers that like warmth, such as Milan, Glass Cui, etc., the room temperature should generally not exceed 12°C. Pomegranates, roses, walnuts, potted grapes, figs, etc. are suitable for low temperatures (around 0℃). If the room temperature is too high, it will affect the full dormancy of flowers and trees or premature leaf budding, which will consume a lot of nutrients. The next year's growth will be weak, no flowering or the flowers will be thin and easy to wither.

(6) Infestation by diseases and insect pests. During the growth and development of gardenias, they are often susceptible to damage by diseases and insect pests, which damages their growth and affects nutrient accumulation. This is also a reason for flower and bud drop.