Exotic Plants

• Greenhouses are controlled environments. The owner can raise or lower the humidity using fans, and the temperature can remain almost constant throughout the year. This allows plants to be brought in from other climates, such as a desert or rainforest, and grow successfully. Cacti, birds of paradise and other exotic plants can be grown in a greenhouse and sold to gardeners who want to experiment with a new species of plant.
  
  

Growing Season

• Due to the controlled temperature and humidity of a greenhouse, plants can be grown year-round, which enables gardeners and farmers to maximize their profits. By keeping the environment of the plants stable, they continue growing and producing fruits and vegetables for much longer than outdoor gardens and plants. This is especially beneficial to individuals who intend to eat or sell the fruit produced.
  
  

Mildew

• One of the negative side effects of growing plants in a greenhouse is the increased risk of mildew. If the greenhouse is allowed to remain humid for a long period, it can promote the growth of mildew, which can damage the roots, stems and leaves of plants. Many plants can be so severely affected by mildew that they must be destroyed to prevent spreading the fungus to other plants in the greenhouse.
  
  

Pests

• Greenhouses often have a lower exposure to pests like locusts and other harmful insects because it is a closed environment. Leaving the windows and doors closed prevents most harmful insects from getting into the building. Additionally, greenhouse plants often receive extra attention and care from gardeners and farmers, which makes it likely that a pest problem will be noticed and solved more quickly.
  
  

Size

• Some plants that might grow to be very large in an outdoor setting are trimmed, pruned and kept very small due to the limitations of a greenhouse. Stunting the growth of larger plants can be done in a way that avoids damaging the plant. Larger plants like trees can be grown inside greenhouses, but the effort is much greater and it is more likely that excessive pruning and stunted growth will kill off these larger plants.