The black leaves of poinsettia are beyond the viewing period.
At this time, the poinsettia can be pruned, and the upper part of the branch is cut off, and only the stem segment with a base of about 5cm is reserved, and 35 buds need to be reserved to germinate again. In order to enjoy poinsettia again, it is necessary to strengthen the management of water and fertilizer, put poinsettia in a place with sufficient sunlight, and keep the temperature within the temperature range, not too high. Prune after autumn, so as to maintain a good plant shape. Keep proper temperature and light in autumn, turn the flowerpot frequently, and you can see the red bracts of poinsettia.
Poinsettia leaves are black, which is caused by black spot.
Black spot disease is mainly a kind of damage to poinsettia bracts. When poinsettia suffers from black spot disease, black spots or mildew spots will grow on the bracts, and the range of spots will sometimes be large, so the leaves of poinsettia are black.
If the black spot disease is confirmed, measures should be taken in time. The incidence of poinsettia is mainly due to wind and rain spreading bacteria, infection with poinsettia plants, poor ventilation, improper lighting, improper water and fertilizer, etc.
To prevent and control black spot disease, we should pay attention to strengthening management, cleaning dead branches and diseased leaves in autumn and winter, paying attention to shaping, strengthening ventilation and light transmission, and reducing the probability of black spot disease of poinsettia. When the disease occurs, it is mainly treated by spraying drugs in time.
What is the reason why poinsettia leaves?
One reason why magenta leaves fall off: the light is too strong.
Poinsettia likes light, and leaves will be redder under suitable light intensity. However, if the sun is too strong in summer and the air humidity increases without timely ventilation, plants will wither and leaves will turn yellow and fall off.
Therefore, poinsettia should be placed in a well-ventilated place in summer, with the spacing between pots being 50 cm, and water should be sprayed on the ground frequently to increase the air humidity, which can effectively control the fallen leaves caused by high temperature drying. Normal lighting can be used in other seasons, but direct blowing of cold air should be avoided.
Poinsettia leaves fall. Reason 2: The temperature is too low.
Poinsettia is not cold-tolerant, and the most suitable growth temperature is 15~20℃. After winter, the temperature should be kept above 15℃ and not lower than 5℃. If you don't move indoors in time and the temperature is not properly controlled, the leaves will fall. In addition, once a cold wind blows in from the window in winter, poinsettia will lose its leaves.
Because low temperature is the cause of poinsettia defoliation, it is necessary to raise the temperature appropriately in winter to keep the plant in a relatively stable environment.
Poinsettia leaves three reasons: improper watering.
Poinsettia likes wet, but is afraid of waterlogging. Pot soil should not be too wet. If you water too much, plants will not be able to carry out photosynthesis well, and plants with poor growth will lose their leaves. Too little watering will cause physiological water shortage of plants and a large number of leaves will curl and fall off.
So poinsettia should be properly watered, not too much. Generally, water is watered once every two days in spring. In summer, when the branches and leaves are flourishing, the plants grow faster and store more water. You can water it once a day to ensure sufficient water, and often sprinkle water to increase humidity. Outdoor culture, in case of heavy rain, should be timely rain.
Four reasons of poinsettia defoliation: improper fertilization
Poinsettia likes fertilizer, and its growth needs various trace elements, especially nitrogen. Without nitrogen fertilizer, leaves are dull and easy to fall off.
Apply sufficient base fertilizer at the bottom of the basin when turning the basin every year. Apply pancake fertilizer every 7 days after pruning, topdressing before flowering, and don't apply fertilizer during flowering, otherwise the buds will be in a hurry. Before entering the house in winter, a small amount of compound fertilizer was applied to help it spend the winter. Be careful not to overdo it when applying fertilizer, so as not to burn the roots.
What if the leaves of Solanum nigrum are black?
Sunflowers are very common. Maybe most people don't know its scientific name, so they usually call it yellow coconut. Sunflower is an evergreen shrub with green overall, no burr on the stem, smooth and slender leaves and high ornamental value. As an evergreen plant, it is also one of the most popular plants in family, work and garden. In fact, the requirements for the environment are very high. Many people often encounter the phenomenon of black leaves when raising sunflower. How did this happen? Let's explain it to you and how to avoid this situation.
First of all, the air is too dry
If you want to plant Solanum lyratum Thunb, you must first understand its growth habits. Sunflowers like warm growing environment, and need to be ventilated frequently to keep semi-cool. Moreover, sunflower is extremely weak in cold tolerance, so it is more delicate. Therefore, if the growing environment is too dry, it will cause the solanaceae plants to lack water, and the lack of overall water supply will easily lead to the overall blackening of leaves.
Therefore, when raising Solanum nigrum, it is necessary to keep spraying water on the leaves and the surrounding growth environment about 4 times a day to improve the humidity of the growth environment once. It should be noted that Solanum nigrum has a dormant period, so don't water it during the dormant period.
Second, the sun is too strong.
Sunflowers like to grow in a semi-shady environment. Too much direct sunlight will easily lead to the leaves turning yellow and drying, which will lead to the overall blackening.
Therefore, it is necessary to avoid too much direct sunlight during the growth period, and the sundew should be placed in the shade.
3. Potted soil is too wet or too dry
Sunflowers like to be wet, so the culture soil is not easy to be too dry, so it is necessary to replenish enough water in time. If you grow in dry soil for a long time, it will also cause the leaves to become black. However, the soil in the basin is too wet, which will affect the growth of roots, easily affect the water absorption capacity of roots and lead to water shortage, thus making the leaves of Solanum nigrum black.
4. Excessive fertilization
No matter what kind of plant it is, there must be a degree of fertilization, not that the more fertilizer is applied, the more vigorous the plant will grow. Too much fertilizer or too high concentration will easily lead to root reverse osmosis, which will lead to the overall water shortage of Solanum lyratum, ranging from burnt leaves to black leaves, and may lead to the death of Solanum lyratum in severe cases.
These situations are easy to avoid. When taking care of plants at ordinary times, we should always observe and maintain them so that plants can grow in a good environment.
I hope everyone can raise green sundew.
Qian Qian konoha black?
Cash cow is adaptable, light-loving and drought-tolerant. Generally speaking, through normal management and ensuring light, water and fertilizer, we can thrive. But many friends report that their cash cow has black leaves, so what should I do at this time?
Causes of leaf blackening of Lysimachia christinae
Winter injury
The incubation period of freezing injury of cash cow is long, so it can't be found in time, and it can only be found in half a month. If there are a few leaves, you can cut them off in time.
brown spot
The most common disease of money tree is brown spot, which is characterized by round or oval spots, turning black in the later period of purple brown, and even turning yellow and falling off leaves in severe cases. The disease is spread by dead leaves or bacteria in the soil through wind and rain, and it mostly occurs in summer with high temperature and humidity and insufficient ventilation.
Improper watering
Too much watering will lead to water accumulation in the soil, lack of oxygen in the roots and black leaves.
Improper lighting
Cash cows should avoid direct sunlight, but they should also pay attention to ensuring adequate illumination.
Insufficient fertilizer
If fertilization is improper, especially when fertilizer is insufficient, it is easy to cause soil nutrient deficiency, resulting in insufficient nutrition of plants and their leaves, and the leaves will turn black.
Control method of black leaf disease of Lysimachia christinae
brown spot
Spray 50% carbendazim wettable powder 600-800 times, 0.5- 10% bordeaux mixture or 50% zineb 1000- 1500 times, or 25% chlorothalonil wettable powder 900 times, once a week 1 time, 2. In addition, reduce humidity and water carbendazim solution when drying.
The problem of water and light
In summer, we should follow the principle of watering when we see it dry, watering when it is dry, and watering when it is watered. You can water it after one month in winter. In addition, it is necessary to move the plant to a sunny place to control the water, then cut off the black leaves and spray chlorothalonil.