10 Most Common Greenhouse Problems

A Greenhouse With Common Problems
(Image credit: Ilse_Innire)

Greenhouses are fantastic tools for the gardener, but the benefits don’t come without their share of issues. There are a number of greenhouse plant growing problems that might crop up, from diseases to insects, as well as problems related to general maintenance. The following discusses the 10 most common greenhouse problems to be on the lookout for.

Greenhouse Issues

Greenhouses allow the gardener to extend the growing season, start seedlings earlier, and overwinter delicate species. Those are just a few of the benefits, but the climate controlled warm and humid conditions preferable to plants also foster insect and disease development. On top of these greenhouse plant problems, there are the general problems with maintenance, most of which are caused by neglect. 

10 Most Common Greenhouse Problems

  1. Likely the biggest issue in greenhouse management is pests. The ideal conditions for growing plants are often also ideal for populations of pests such as aphids and thrips. Both not only damage plants, but also act as vectors for disease. Aphids attract ant populations as well. 
  2. Aphids and thrips aren’t the only pests attracted to the comfortable conditions inside a greenhouse. Other pests likely to be found include fungus gnats, shore flies, bloodworms, whiteflies, leafminers, mealybugs, and mites. Creepy crawlers like cutworms, army worms, loopers and other caterpillars may make their way into the greenhouse, as may snails and slugs. 
  3. Pests are not the only unwelcome guests to plague the greenhouse. Diseases are another greenhouse plant problem. Diseases such as botrytis, rusts, root rots and powdery mildew are fairly common in the greenhouse. All are fungal diseases caused by spores that are moved about by air currents or water droplets. 
  4. A variety of viral infections may afflict greenhouse plants. Greenhouse growing problems may be the result of viral infections such as Impatiens Necrotic Spot Virus (INSV) or Tomato Spotted Wilt Virus, both the result of thrips populations as well as numerous other viruses. 

Additional Greenhouse Issues: Management

  1. Clogged air filtration systems are a common greenhouse issue that can be remedied by changing the air filters on a regular basis. 
  2. Temperature swings can be a major issue in the greenhouse. The structure may become too hot due to inordinately high temps or wild fires. Overly hot greenhouses may use shade cloth or a greenhouse whitewash to control both ambient and radiant temps Greenhouses that tend to stay too cold can be managed with thorough, routine inspections and maintenance of existing heating systems.
  3. Issues with irrigation and/or fertigation systems are another headache for the greenhouse operator. Timely repair or replacement of defective equipment is the key to managing this greenhouse issue. All systems should be flushed and drippers cleaned regularly with a hydrogen peroxide and water solution to minimize clogging. 
  4. Mold issues are yet another issue when it comes to greenhouses. Mold encourages pests and diseases, sometimes to the extent that an entire system needs to be decontaminated. Ideally, you should disinfect systems, including lines and water tanks, after each harvest using a water and hydrogen peroxide mix. 
  5. The accumulation of fertilizer salts in fertigation lines can result in a spike in nutrient solution electrical conductivity. Regularly inspect and clean fertigation lines and injectors to prevent under or over fertilization. 
  6. Lastly, if crops seem to be dehydrated on a regular basis, inspect any related water, timing and cycle controls for clogs or failures to prevent under or over watering. 
Amy Grant

Amy Grant has been gardening for 30 years and writing for 15. A professional chef and caterer, Amy's area of expertise is culinary gardening.