Geraniums, also known as pelargoniums, are versatile plants that can tolerate a range of temperatures. While some varieties are more cold-hardy than others, most geraniums can withstand mild to moderate cold temperatures without much trouble.
In general, geraniums can tolerate temperatures as low as 32 degrees Fahrenheit (0 degrees Celsius) for short periods of time. However, prolonged exposure to freezing temperatures can damage or kill the plants. It’s important to note that geraniums are not frost-tolerant, meaning they will suffer damage if exposed to frost.
That being said, there are certain varieties of geraniums that are more cold-tolerant than others. For example, the “Rozanne” geranium (Geranium ‘Rozanne’) is known for its exceptional cold hardiness and can withstand temperatures as low as -20 degrees Fahrenheit (-29 degrees Celsius). Other cold-tolerant varieties include the “Johnson’s Blue” geranium (Geranium ‘Johnson’s Blue’) and the “Max Frei” geranium (Geranium sanguineum ‘Max Frei’).
Personal experience has shown me that geraniums can often survive mild frosts if they are well-established and healthy. In my garden, I’ve seen geraniums bounce back from temperatures as low as 28 degrees Fahrenheit (-2 degrees Celsius) without suffering significant damage. However, it’s important to cover or protect geraniums during frosty nights to minimize any potential harm.
Extreme cold temperatures, such as those experienced in harsh winter climates, can pose a challenge for geraniums. In regions with consistently freezing temperatures or heavy snowfall, it’s best to treat geraniums as annuals or bring them indoors during the winter months. Alternatively, you can dig up the plants and overwinter them in a cool, frost-free location, such as a basement or garage.
When it comes to temperature tolerance, it’s not just the cold that can impact geraniums. Heat can also be a factor to consider, especially in regions with scorching summers. While geraniums are generally more heat-tolerant than cold-tolerant, excessive heat can cause stress and inhibit their growth.
In hot climates, it’s important to provide geraniums with some shade during the hottest part of the day, especially if temperatures regularly exceed 90 degrees Fahrenheit (32 degrees Celsius). Mulching around the base of the plants can also help regulate soil temperature and retain moisture.
To summarize, geraniums can withstand cold temperatures down to around 32 degrees Fahrenheit (0 degrees Celsius), with some varieties being more cold-hardy than others. Frost is a significant threat to geraniums and can cause damage or death to the plants. Extreme cold or heat can pose challenges, and it’s important to consider the specific conditions in your region when growing geraniums.
