Wilted And Diseased Orchid Plant
(Image credit: Fabian Loeffelmann)

Orchids may be one of the most feared houseplants in the arsenal; gardeners everywhere have heard how fussy they are about growing conditions and all the problems growing orchids other people have experienced. The truth is that orchids are relatively sturdy, have few serious problems, and many grow quite easily in an indoor environment. It helps to know a little more about common orchid problems before you buy your first plant. Read on to prepare for your orchid adventure.

Problems Growing Orchids

Even with the best of care troubles can occur. Common orchid problems include environmental issues, a few pests, and diseases.

Environmental Problems

Environmental issues with orchid plants are the most common complaint of first-time growers. People try to treat these plants like other houseplants, resulting in chaos. Most orchids are epiphytes, plants that grow in the branches of trees in very little soil using their roots both to cling to trees and respirate; many even have photosynthetic organs located in their prop roots. Because of this, orchids are very sensitive to environmental changes.

  • Bud blast - Bud blast is a common sign of problem conditions. If your buds dry up and die without any sign of pests or disease, your orchid may need higher humidity or brighter lighting. Incorrect watering can cause this problem, along with distorted or wrinkled foliage.
  • Poor light conditions - Orchid foliage changes color in response to lighting conditions, and too much light may cause yellowing of tissues or a purple cast, depending on the species. Not enough light usually causes dark foliage to develop.
  • Potting mediums - Proper potting is also vital for success. Orchid roots must be able to breathe in their containers, which is why orchids normally come packed in moss. As the medium or moss ages, it breaks down, squeezing the air pockets between areas ever smaller, reducing orchid growth and giving plants a generally unhealthy look. Repotting is as important for orchid health as fertilizer and consistent temperatures.

Orchid Pests

Most orchids are grown indoors, limiting the pest problems they experience, but the pests that tend to plague other houseplants also affect orchids. Keep your eyes peeled for mealybugs, spider mites, scales, and thrips on your plants. Sap-suckers like mealybugs, spider mites, and scales can blend into the background, but leave foliage covered in yellowing spots that seem to increase over time.

  • Mealybugs and scale - Mealybugs and scale are generally immobile pests that grow cottony or waxy covers to protect themselves.
  • Spider mites - Spider mites are hard to see with the naked eye, but often leave fine webs where they've been feeding.
  • Thrips - Many thrips species feed on pollen and can be observed running around on blooms.

No matter which of these pests is bugging you, a thorough coating of insecticidal soap will kill them on contact. Continue checking and spraying your orchids weekly until the pest problem is gone.

Orchid Diseases

Fungal and bacterial diseases of orchids are common because of the high levels of humidity they need to survive. Fungal agents cause problems like root rot, leaf spots, leaf blights, and spots on flowers.

  • Root rot - Root rot may present as a general yellowing of the plant, but if you inspect the roots you'll see that they're black or brown and mushy. Remove these damaged roots and reduce waterings - orchids should never be in standing water. Instead, increase humidity by raising them above the water level with small stones.
  • Leaf spots and blights - Many fungal leaf spots and blights can be treated with neem oil.
  • Bacterial rot - Bacterial rot causes damaged leaves and crowns to turn to mush and collapse. Even a tiny bit of damage may be enough to allow bacteria to penetrate leaves when your orchid is living in a warm, wet area. Use a copper-based spray to treat your plant after removing severely damaged leaves with sterile tools.
Kristi Waterworth

Kristi Waterworth was a regular contributor to Gardening Know How for many years, answering countless queries on plant pests and diseases.