Orchid diseases: causes, treatment and prevention

We generally buy orchids with their flowers already in bloom. The variety of colors in their blooms attracts admirers of this aristocratic beauty. Flower stalks decorate your home for 2-3 months after purchase. Then they fade, and the next blooms take a while to appear. With proper care, your orchid will soon delight you with repeat blooms; the key is to protect it from diseases and pests. A diseased orchid will be unable to form buds, will wither, and is highly likely to die.

Orchid flowering problems

Before attempting to stimulate flowering, it's important to understand the reasons for its absence. There could be several possible causes, including adaptation to a change in environment, a lack of phosphorus, excess nitrogen, a natural break in flowering, or a fungal disease.

The orchid does not bloom

Hybrids begin to bloom after two years. Flower stalk formation begins after 6-8 leaves appear. The number of buds on a single branch ranges from 6 to 35. Sometimes an orchid produces a stalk in the first year of its life; when this occurs, it lacks the strength to maintain its flower stalks and sheds them. You can determine the symptoms by examining the plant, then identifying the problem and finding a solution. If it's a disease, begin treatment; if it's a nutritional deficiency, fertilize; if it's root rot, it's best to remove the plant.

Improper care:

• dry air;
• lack of light;
• disturbed during a period of rest;
• drafts;
• low air temperature;
• wrong substrate;
• high humidity.

Orchid buds are wilting

Flower buds wilting is not uncommon. Orchids are very sensitive to environmental changes, temperature fluctuations, drought, and lack of light. The room temperature should be 21-25°C. During dormancy, keep it at least 13°C. Humidity should be 70-80%.

Reasons for wilting buds:

Garden soil is not suitable for growing phalaenopsis. It contains excess moisture and a large amount of minerals. The mixture should contain only peat, pine bark, coconut fiber, a little sand, and agroperlite.

Dark spots on flowers

Black spots on orchid leaves can appear as a result of sunburn. Orchids are best placed in areas with indirect light. Dark spots on orchid leaves can also indicate late blight. This fungus is dangerous for the orchid and can kill it. The spots initially appear purple, then darken. Frequent watering is the cause.

Chlorosis can also cause blackened leaves. When leaves darken, they curl. Fungus also actively develops within the plant tissue.

Black-brown lesions, convex in shape, with a pattern in the form of rings, stripes, mosaics - symptoms of viral diseasesThe spots may turn yellow, then the orchid's leaves turn black and the leaf blade is destroyed.

The only solution is to destroy the plant. The virus is incurable, but there's a high risk of widespread infection, which can easily spread to neighboring flowers. Aphids carry the virus, so insect control is essential.

Along with the black spots, yellow spots appear. These appear when sunlight hits the leaves. To eliminate the problem, move the plant to a safe location.

Bacterial diseases of orchids

When buying a plant in a store, you need to examine the entire flower carefullyIf you notice any stains, mold, light or dark circles, or deformation, it's best to leave the item on the counter.

Brown bacterial rot

Brown spots appear in rooms with high humidity and low temperatures. The fungus gradually affects all parts of the plant. Bacterial rot covers the leaf blade. The spots become water-soaked, gradually darken, expand, and merge. The infection most often affects young leaves.

If the damage is small, the plant can be helped. To do this, cut out the infected areas with a clean knife down to healthy tissue. Sprinkle the cut with charcoal. If the infection is extensive, treatment will not help; the plant should be removed and the soil replaced.

Root rot

High temperatures and high humidity encourage fungal growth. Leaves become covered in brown spots, the rhizome becomes soft, and the orchid's white roots begin to turn black at the base.

The roots and soil are treated with a 0.2% solution of Fundazol or 0.2% Topsin. The treatment is repeated three times every two weeks. You can also immerse the container with the flower in the solution for a few minutes. As a preventative measure, the substrate is disinfected before planting.

Gray rot

A gray, fluffy coating on the foliage indicates a gray mold infection. Brown spots appear on the orchid flowers. This can be caused by excessive nitrogen application, low temperatures, or excessive moisture.

Affected areas are removed, and the plants are sprayed with fungicides. The substrate and container are also treated.

Black rot on an orchid

Heat-loving flowers can become infected with black rot. Orchids' leaves turn black due to hypothermia. The fungal infection affects the lower part of the plant, including the roots. Black spots appear on the leaves, and this condition is more common in plants with weakened immune systems. Other diseases or pests can also reduce the plant's vitality.

The orchid needs to be repotted immediately into a new container with clean potting mix. Before repotting, cut out any diseased spots with a knife, remove any black roots, and treat with Bordeaux mixture. The orchid requires careful care. If the rot has spread to a large part of the plant, it must be destroyed. There is a high risk of infecting neighboring orchids.

Fusarium rot

When the room is not ventilated and the humidity is high, fusarium occurs. The leaves are turning yellow, become soft, curl over time, mold appears on the roots and a pink coating appears on the leaves.

Treat the foliage with Fundazol (0.2%) three times daily; continue to use the treatment throughout the course of the disease. Temporarily stop watering and avoid drafts.

Orchid diseases and their treatment

Diseases should be detected promptly, noticing any changes in the plants. The key is not to miss the window of opportunity to help the flowers. Small affected areas can be treated. In case of a large-scale infection, the orchid should be destroyed. If preventative measures have been taken, the disease is not life-threatening.

Anthracnose

Stagnant water on the leaves and high humidity contribute to the development of anthracnose. Dark brown, circular spots with clear borders appear on the leaves. Over time, the damage increases, developing a pink or black coating.

Reduce room humidity to 40-50%. Ventilate the room thoroughly and avoid exposing foliage to water. Remove diseased leaves, and treat cuts with ash or charcoal. Move the orchid to a dry location, regularly draining the water from the tray. In severe cases, use chemical treatments such as Ridomil, Skor, Topsin-M, and Mikosan.

Bacterial leaf spot

During hot weather, there's a high risk of infectious disease. It appears as dark, sunken spots with a yellow border. Bacteria enter through damaged leaf blades. The leaf tips are damaged first, and then the entire leaf blade becomes moldy. Bacteria can be introduced through soil, water, or pests.

The spots are cut out, the cut is dusted with charcoal, and coated with brilliant green and iodine. The orchid is temporarily isolated from neighboring plants. If dark spots have not appeared within 7-10 days, the orchid is returned to its original location.

Powdery mildew treatment on orchids

White spots appear on the leaves. White mold on the orchid covers all parts of the plant, as if it had been dusted with flour. White spots on orchid leaves appear in high temperatures and high humidity. Plants become overheated and rot, and mold appears in the orchid pot.

Powdery mildew can be prevented by spraying the orchid with Fitosporin. Treatment is carried out with Skor. Spray the medication on the parts of the plant where the white spots appear, excluding the flowers. Another option is to use colloidal sulfur, applying it strictly according to the instructions.

Rust

Rust is a rare disease for orchids. It is caused by a fungus that thrives on weakened plants. A rusty tint appears on the underside of the leaf.

The affected areas are cut out, and the cut is treated with a 25% alcohol solution. The infected plant is treated with Mikasan, Ritomil, or Skor. The products are sprayed onto the plant parts.

Sooty (black) fungi

Pests (scale insects, aphids, and mealybugs) that infest orchids block light from reaching the orchid. They clog the entire base of the leaf. The mealybug is the most dangerous, as it feeds on the plant's sap and secretes a toxin. Black spots appear on the flower's sensitive areas, and when the leaf turns black, it falls off. The plant weakens and dies. Infestations most often occur in winter or when there is an excess of nitrogen.

A 0.3% foundation solution or a 0.2% benlate solution will help treat the plants. The orchid is completely immersed in the mixture for several minutes. Intervals between treatments should be 15 days. As a preventative measure, neem oil can be used, or the soil can be watered with warm water (50-55 degrees Celsius). Pests die at 40 degrees Celsius.

Fungal diseases of orchids and their treatment

Fungal spores thrive in humid environments. High temperatures and moisture encourage fungal growth. A white coating on the roots and trunk, darkening of the leaves, and various spots appearing on the orchid are signs of a fungal infection.

Preventative measures and proper treatment help get rid of mold on orchids. The sooner the problem is detected, the faster the plant will recover. Chemicals that help quickly get rid of mold are available in stores. At-home treatments include Fundazol, Fitosporin, Bordeaux mixture, Quadris, Mikasan, Skor, Ritomil, Chistotsvet, and Fozalon.

Rules for treating fungal leaf diseases:

• isolating the diseased bush from other plants;
• removal of all infected parts;
• disinfection of the cut, treatment with coal, ash, alcohol, iodine, cinnamon, chlorhexidine;
• the plants need to be treated with fungicides;
• replacing the pot and substrate;
• After processing, the instruments are calcined over a fire and treated with alcohol.

In addition, reduce watering, ventilate the room, and avoid drafts. Water only when the substrate dries out early in the day.

Non-infectious diseases of orchids

Non-infectious damage occurs as a result of heat exposure or sunburn. The plant can be damaged by both sunlight and cold air. Proper care at home is essential.

Leaf deformation

Fractures occur as a result of mechanical action. However, there is another type of leaf blade deformation caused by a lack of moisture or severe hypothermia. Some areas of the leaf become irregularly shaped and appear crushed. This can be caused by overfertilization with nitrogen. fractures and cracks appear, color change.

You need to reconsider the temperature regime, increase watering, and avoid nitrogen fertilizers. Remove the plant from the pot, rinse the roots, and then repot it in a different medium.

Leaf burn

Burns can be caused by heat or sun. Colorless lesions with a brown border appear in spring or summer during intense sunlight. Evaporative burns are caused by water droplets on the foliage. Thermal damage occurs from low-mounted lamps during backlighting, resulting in dry streaks or spots on the foliage.

Sun-loving species should be gradually acclimated to sunlight starting in spring. Radiant heat can also cause burns when leaves hang low over a radiator. Burns are caused by heat and are not a disease. Damaged leaves should be removed. Place the plant in a location with indirect light or shade a window.

Frostbite

Frostbite occurs in late autumn or winter when phalaenopsis Standing near an open window or touching the window glass, wrinkles and bumps appear on the leaves, which eventually turn into spots.

Damaged leaves do not recover and are trimmed off. The bush is moved to a warm, draft-free location. Leave the plant undisturbed for about 8-10 days without watering or fertilizing. If a growing point is frostbitten, remove it. This orchid will only reproduce from a basal cutting.

Tips and Prevention

After purchasing a new orchid, it needs to be quarantined. Place it in a separate room. After the stress, the plant will need a month to adapt to its new location. Treating the rhizome and leaves with tetracycline is acceptable, although this doesn't always help.

Adviсe:

1. It's best to mist the plants twice a day, avoiding the flowers. In summer, water once or twice a week; in winter, water once or twice a month. Avoid watering with cold water, as this will rot the roots. Warm the water to 35-40 degrees Celsius.
2. To soften the water, place a piece of peat in a bucket wrapped in cheesecloth at a ratio of 10 g per 10 liters of liquid. Use purified water for irrigation; melted snow or rainwater is acceptable.
3. Good drainage must be ensured.
4. Temperature fluctuations should not exceed 4 degrees; the norm is 20-24 *C. Fertilize the orchid 1-2 times a month.
5. For planting, use lightweight containers; holes are made in the pots for ventilation; holes are needed on the walls and bottom of the pot.
6. You can maintain humidity using an aquarium; simply place orchids next to it.
7. As a preventative measure, the orchid is sprayed once every 30 days with a solution of copper sulfate.
8. Feeding plants with potassium will strengthen the plant's immunity.
9. It's better to buy a ready-made orchid mixture from a store; the substrate goes through all the processing stages.
10. To combat moss or algae, wrap the pot in foil and place a dark planter inside.

To induce flowering, place the orchid pot in a dark place with a temperature of 15°C (59°F). Add phosphorus fertilizer and increase the humidity in the room. Then, place the pot in a dark corner for 5-6 days. After 3 weeks, buds will appear and will bloom for a long time.

Don't discard an infected orchid immediately until you've exhausted all treatment methods. Strengthening the immune system is the key to fighting disease. A healthy plant will resist many infections. If you're buying an orchid for the first time, you should consult with a specialist about how to care for it to ensure the young plant stays healthy and blooms for a long time.