Cactus Frost Damage

Depending on where you live you may have to deal with below freezing temperatures. When a Cactus or Succulent freeze it generally manifests on the growing tip, like this;

Think of it like frostbite on a person, it happens on the extremities such as fingers and toes. Plants from different regions will have different temperaturs thresholds. For example: The picture above is Mexican Fencepost and it showed this damage after one morning at 29°F. On the other end of the spectrum Opuntia humifusa is hardy to at least -25°F.

Some Cactus and Succulents present more dramatic color on their flesh when they are showing signs of cold stress. This presents itself in winter and is more dramatic as the plant gets closer to its lowest cold tolerance.

Heres an example of my seed grown Stenocereus gummosus showing signs of cold stress.

The popular Purple Prickly Pear Cactus (Opuntia violaceae var. santa rita) is a great example of this. The more exposed to the cold the more dramatic its purple coloring.

And Firestick (Euphorbia tirucalli - 'Sticks on Fire') is another great example.