14 common diseases in houseplants

It can take a long time and patience to understand the needs of a particular plant. But if you’ve tried lots of options and the flower still doesn’t look good, take a closer look: it could be due to a disease.

Below is a list of the most common indoor plant diseases. Of course, control measures and the chance of victory strongly depend on the degree of infestation. But if it is small, you can do with simple and safe for household means.

The main diseases of plants: how to identify and what to do

bacterial blotch

Bacterial spotting

  • Factors of development: high temperature and humidity of the environment
  • Signs: small dark embossed spots
  • What to do: get rid of the affected plants and conduct a fungicide treatment



  • Causes: low temperature and high humidity environment
  • Signs: large yellow spots on leaves, gradually changing color to brown
  • What to do: Get rid of the diseased plants and make sure the remaining specimens are not standing too close together

bacterial wilt

Bacterial wilt (brown rot, brown bacteriosis)

  • Causes: contaminated soil or weeds
  • Signs: leaves fading during daylight hours, gradually changing color from green to yellow
  • What to do: Get rid of the affected plants and replant the rest in new disinfected soil

black leg

Blackleg (black root rot)

  • Causes: damp soil and holding temperatures below 12-18 degrees (depending on species)
  • Signs: stunted above-ground part of the plant and appearance of black spots on the root system
  • What to do: Use fungicide as a preventive measure



  • Attracting factors: warm environment and high nitrogen content during the active growth stage
  • Signs: small green or yellow insects on leaves and stems
  • What to do: Wash the plants with a soapy solution or rub them with rubbing alcohol (don’t forget to protect the earth so as not to damage the roots); treat them 3-4 times at intervals of 5 days

cucumber mosaic virus

Cucumber mosaic virus

  • Causes: Aphid infestation
  • Signs: yellow spots or streaks on leaves
  • What to do: Get rid of the infested plants and thoroughly check the remaining ones for aphids

grey rot

Gray rot

  • Causes: withering or damaged plant parts – leaves, petals
  • Signs: dark or light brown rot around the lesions
  • What to do: Remove and get rid of the diseased parts of the plant and treat with fungicide

false powdery mildew

False powdery mildew

  • Causes: high humidity for a long period of time
  • Signs: white powdery mildew, mostly on the underside of leaves
  • What to do: get rid of the affected plants and keep the rest far enough away for normal air circulation

cylindrocladium rot

Cylindrocladium rot

  • Causes: high humidity and excessive watering
  • Signs: usually dark brown spots on leaves
  • What to do: Get rid of the affected plants and replant the rest in sterile soil

angular leaf spotting

Angular leaf spotting

  • Causes: seeds and cuttings from infected plants, close to greenhouse conditions provoke the development of the disease
  • Signs: oily spots on leaves, followed by holes in their place
  • What to do: Take seeds and offspring from healthy plants and lower the moisture level


Rhizoctoniosis (black scab)

  • Causes: warm, excessively moist soil
  • Signs: rot on the root part of the stem with brown or red areas of lesions
  • What to do: Get rid of the affected plants and conduct a fungicide treatment

spider mite

Spider mite

  • Attracting factors: high temperature
  • Signs: thin cobwebs on the underside of leaves
  • What to do: isolate the diseased plant, remove the diseased leaves and wash the windowsill and above-ground part with a soapy solution or insecticide every 3 days until the signs of infestation disappear



  • Causes: seeds and cuttings from infected plants
  • Signs: Leaf tips turn yellow and then brown
  • What to do: Remove damaged leaves and keep watering more moderately

powdery mildew


  • Attracting factors: excessive watering and high nitrogen content in the soil
  • Signs: small white insects with a white fluffy plaque
  • What to do: Once every 7 days, remove the worms with absorbent cotton or cloth soaked in rubbing alcohol or insecticide until the signs of infestation are gone

A few words about fungicides

Fungicides are very effective as a preventive measure against the development of diseases, especially – for plants with low resistance to fungi. If you do not want to deal with chemicals, there are natural alternatives:

  • Milk and water in a 1:1 ratio is sprayed on leaves when affected by powdery mildew.
  • Also used as a fungicide is a mixture of 1 teaspoon of baking soda, 1 teaspoon of vegetable oil and a couple of drops of dishwashing detergent.