Will My Petunias Die at 29 Degrees?

Petunias are hardy plants that require very little special care. However, these plants have a temperature threshold where even healthy petunias will freeze and die. Some petunia varieties will die at 29 degrees Fahrenheit, but others can withstand temperatures as low as 25 degrees Fahrenheit.

Types

• There are many types of petunias. Most "Supertunia Surfinia" petunia varieties will survive at 25 degrees and above. These varieties include common red, white and lime "wave" petunias. Almost all other petunias die when the temperature drops to 30 to 35 degrees Fahrenheit.
  

  Significance

• Petunias are annuals — they complete their life cycle in just one year. However, petunias self-seed, and new petunia plants can regrow in the summer. If the petunias freeze before they naturally germinate and die, there is no chance of regrowth.
  

  Prevention

• Petunias have a shallow root structure. Dig to about 4 to 6 inches deep and remove your petunias from the garden before it gets too cold for them. Place them in indoor pots to prevent cold damage, and make sure you place the pots near a window with at least six hours of direct sunlight.