What are the tips for growing roses? Why are there black spots on the leaves?

There are three possible causes of black spots on the leaves of roses. One is excessive watering, it has drought tolerance, too much watering can not absorb it, there will be stagnant water, easy to root roots, resulting in the normal delivery of nutrients to the branches and leaves, and the leaves will leave black spots after a long time. The second is that the light is too dark, and photosynthesis cannot be carried out normally in a cool or too weak place, and black spots will be left after a long time.

The third is that he is infected with black spot disease. Once found, the diseased leaves should be cleaned up and sprayed in time.

First, the breeding environment.

1. Soil: Choose the soil suitable for the growth of roses, and generally use loose, well-drained and well-aerated soil.

2. Watering: You don't need to water the roses too much, if you water frequently, there will be rotten roots, especially in rainy weather with high humidity, you must control the amount of watering.

3. Fertilization: It should be given light fertilizer, if it is given a thick fertilizer, it will burn the roots, water a light water fertilizer once in about 15 days, you can use Bika foliar fertilizer or fermented rice water, generally the leaves are bright without fertilization.

4. Light: Roses need sufficient light to grow, give it more than 4 hours of light every day, if it is placed in a poorly ventilated place for a long time, the leaves will turn yellow, and it is best to put it indoors by the window when the temperature is low.

Second, the method of reproduction.

1. Sowing and propagating: put the collected seeds in a bag filled with sandy soil, warm to 20 after a month, and sow seeds after germination, and then plant when the seedlings grow 3-5 leaflets.

2. Divide and propagate, cultivate the roots of roses, let each branch grow a new root system, and cut the side branches that grow new roots when changing pots, and it will become a new plant.

3. Common pests and diseases.

1. Scale insects: once they appear, it is difficult to deal with, usually put it in a well-ventilated place, properly cut off excess branches, strengthen ventilation, potting soil can not have stagnant water, when there are spots on the branches, it should be scraped off in time, and the whole branch will be cut off if the disease is serious, and at the same time spray with pesticides.

2. Powdery mildew: After being affected by the disease, the leaves will be raised, and there will be powdery powder, and a layer of mold will appear in the buds and branches of the disease, so it is necessary to spray the agent regularly, and the branches and leaves of the disease should be cut off immediately, which can reduce the chance of the spread of the source of the disease.

Choose the right location: Roses prefer sunny, well-ventilated, well-drained environments, so choose to plant in a place with plenty of sunlight and be careful to avoid damp and watery areas.

Control the amount of watering: Roses need the right amount of water, but too much water can lead to root rot and germ growth. Therefore, it is necessary to control the amount and frequency of watering, generally once a week, and water thoroughly each time.

Fertilization: Moderate fertilization can promote the growth of roses, but excessive fertilization can lead to problems such as yellowing of leaves and withering of flowers. In general, fertilize once a year in spring and autumn, and do not fertilize in summer.

Pruning: Pruning promotes the growth and flowering of roses, while also facilitating ventilation and pest control. In general, a moderate amount of pruning can be done in both spring and autumn.

Also, regarding the black spots on the leaves, it may be due to rose black spot disease. This disease is caused by fungi and can cause black spots to appear on the leaves and even cause the leaves to wilt. Ways to prevent and ** this disease include:

Prevent excessive moisture and avoid dampness of the leaves.

Remove fallen leaves and dead branches regularly to reduce the growth of germs.

Use drugs to spray or apply, such as chlorothalonil, Pythium, etc.

Avoid pruning and pruning during the germ-prone season to avoid infection of the wound.

The solution to the black spots on the leaves of the rose is to use 75ml of quick net, 15ml of garlic oil, 25ml of foliar fertilization, 15kg of spray mixed with water, once every 3 days, and use it 3 times in a row.

Rose black spot is an important disease of roses and moons, and it is also one of the common diseases, and the damage is serious. It mainly damages leaves, petioles, twigs, peduncles and flowers. The leaves are infected with small brown spots in early spring, which are purple-brown to black-brown, round or irregularly shaped lesions after expansion, with a diameter of 2-15 mm or larger, radial edges, and sometimes the lesions cover a large area of surrounding mesophyll tissue and turn yellow.

Dark spots on the leaves of roses may be overwatered, or too dark, or infected with black spot. Once found, the diseased leaves should be cleaned up and sprayed in time.

1. Overwatering.

Dark spots on the leaves of roses may be overwatered. It is a shallow-rooted plant and is also drought tolerant. If it is watered too much or too often, it is easy to accumulate water, easy to rot roots, it can not deliver nutrients to the leaves, and the leaves are easy to grow black spots after a long time, and even fall off.

In this case, it is recommended to remove the pot and repot, and in the process of changing the pot, it is necessary to trim the roots, disinfect, dry the wound and replant. In the later stage, pay attention to reducing the amount of water, do not dry and do not water at will.

Second, the light is too dark.

Roses prefer to grow in a well-lit environment. If it is placed in a cool place or a low-light place for a long time during the management period, it will affect the photosynthesis of the leaves, resulting in poor growth, and the leaves are prone to dark spots. In this case, move to the light as soon as possible and let it bask in the sun.

The daily light exposure time should be more than 6 hours in order to maintain normal growth. Pay attention to slowly increase the light intensity, and do not directly expose to strong light to avoid injury.

3. Infection with diseases.

Dark spots on the leaves of roses can also be infected with black spots, especially between July and September. Once infected with this disease, it will seriously damage the leaves, easily lead to defoliation, and also affect flowering. Diseased leaves should be removed in time and completely destroyed.

It is also necessary to spray drugs, with chlorothalonil or zebze, and with Bika foliar fertilizer, spray once every 7-10 days, and spray three or four times in a row.

The causes of the blackening of the leaves of potted roses are mainly divided into two categories: physiological causes and pathological travel causes

1. Physiological reasons: First, due to Hu Zhenbo's poor management of the water content of potted roses, and the location of the potted plants is not well ventilated, the leaves of potted roses will be black and curly in the later stage of white powder; The second is due to the lack of phosphorus in the substrate for cultivating roses.

2. Pathological causes: Fungal diseases of plants cause the leaves of plants to turn black in the form of soot.

Rose black spot is an important disease of roses and moons, and it is also one of the common diseases, and the damage is serious. It mainly damages leaves, petioles, twigs, peduncles and flowers. The leaves are infected with small brown spots at the beginning, and after expansion, they are purple-brown to black-brown, round or irregularly shaped lesions, 2-15 mm in diameter or larger, with radial edges, and sometimes large areas of mesophyll tissue around the lesions turn yellow.

In the later stage, black, shiny blister-like protrusions appear on the lesions, i.e., the conidia disc. The petioles and shoots are oblong to strip-shaped, purple-brown to black-brown, slightly depressed, and the surrounding tissues are slightly wrinkled. The peduncle and calyx infection lesions are small and inconspicuous.

When the condition is severe. A large number of leaves fall off, resulting in bare branches, weakened trees and even the death of the whole plant. The main insect pests are aphids, red spiders, leaf-cutting wasps, caterpillars, scale insects, leaf mites, and inchworms, etc., all of which do not have black grains on the back of the leaves.

Yellow leaves are also a late symptom of brown spot disease, and it is also related to the fact that you wash them with soap.

In the middle and late stages of the disease: use 75ml of Sujing + 15ml of garlic oil + 25ml of foliar fertilization, spray with 15 kg of water, once every 3 days, and use it 3 times. After the disease is controlled, it is switched to a prophylactic regimen.

Prevention plan: 50ml of Oli-gram (quick net) mixed with 15 kg of water, 1 time in about 7 days. **Scheme: 50ml of Ao-Li-gram (quick net) + 15-20ml of garlic oil, 1 time for 3-5 days, 2 times in a row.

Strengthen management, timely and reasonable fertilization, and enhance plant disease resistance; Prune in time to improve ventilation and light transmission conditions between plants, reduce humidity, and avoid foliar water storage. Remove diseased fallen leaves at any time and burn them intensively, and completely prune diseased branches in autumn.

Potted flowers often have yellowing leaves due to improper cultivation management, which affects the normal growth and development of potted flowers. There are many reasons why leaves turn yellow, how do you know the cause of yellowing? It is mainly judged by the yellowing of the leaves.

Wet yellow: the apical heart of the new shoots is atrophied, the young leaves are pale yellow, and the old leaves are also darkened yellow. The reason for this is that the soil is too wet due to excessive watering, resulting in dust destruction and lack of oxygen, and some fibrous roots rot. In terms of prevention and control, appropriate control of watering amount can be taken to strengthen the loosening of soil.

Dry yellow: The apical and new leaves are normal in color, and the lower leaves gradually dry and yellow upwards fall off or are scorched. The main reason is dehydration or not watering for a long time, causing the lower branches and leaves to die of old age. In terms of prevention and control, it can be properly watered to ensure that the potted flowers are kept moist and moist.

Fat yellow: the new leaves are thicker and shiny, the leaves are wavy and concave and convex and not stretched, and the old leaves are yellowing and falling off. In terms of prevention and control, fertilizer should be stopped immediately, and the amount of watering should be increased at the same time.

Hungry yellow: potted flowers appear with tender branches, thin leaves, and long nodes. The reason is that the pot has not been changed for a long time or the plant is large and the pot is small, the fertilizer and water are insufficient, the fibrous roots in the pot are senescent or too dense, and the sun-loving flowers are not enough light. In terms of prevention and control, it is necessary to pour pots in time, gradually increase water and fertilizer or enhance light.

Alkali yellow: alkali yellow often occurs in flowers that like acidic soil, such as rhododendron, white orchid, gardenia, camellia, etc., especially in the north potted plants, due to the alkaline water and soil, causing the leaves to gradually fade and turn yellow or fall off. The control method is to change the peaty soil or the culture soil with sulfur powder for cultivation.

Ferrous sulfate can also be poured once a week. At the same time, it also has a certain prevention effect to loosen the potting soil and drain the branches.

Aging yellow: such as white orchid, hibiscus and other flowers, after germinating new branches, the old leaves are yellow; After transplanting, yellow leaves and fallen leaves appear due to nutrient disorders or dense branches and leaves in the outer layer of the canopy, and insufficient light in the inner chamber. In winter, some deciduous flowers have yellowed leaves after frostfall, withering and withering, which is a normal phenomenon. But I can't help you with the black spots, forgive me.

Black spot feast liquid disease, irregular small black spots appear on the leaf surface of the affected plants, and the diseased leaves are yellow and fall off, and the disease is serious in case of autumn rain. Pay attention to ventilation and humidity, and spray 1000 times the "killable" powder or the equivalent Bordeaux liquid once a week. After the rose is dormant in the summer, it begins to grow vigorously and should be fertilized weekly.

According to the time of pruning (such as New Year's Day, Christmas, Valentine's Day) and other arrangements to promote germination and flower branches, the number of days from germination to flowering varies depending on the variety and temperature, the balance is usually 40-60 days, and the winter core type roses begin to cut flowers on the market this month.