Winter brings a serene and often magical transformation to our landscapes as snow blankets the earth. However, for cactus gardeners, the start of winter can be a time of concern. Cacti, with their reputation for thriving in arid desert conditions, may appear ill-equipped to handle the harshness of cold weather. Yet, with the right care and precautions, you can safeguard your cherished plants from the dreaded winter burn damage that can occur during frigid months.
So, how do you protect your cactus plants from winter burn damage? You can help your cactus plants adapt to winter conditions by watering them less frequently, sheltering them, using mulch, moving them indoors, or making a frost blanket.
Read on for more details.
How Does the Cold Damage Plants?
Extreme cold affects plant tissue in two main ways. The first relates to plant biology.
Like any other organism, there’s an ideal temperature for all cellular processes that plants require to thrive. The colder the plants get, the harder it becomes for them to keep up with these processes.
Most plants become dormant at this point, just as deciduous trees do in winter. However, dormancy cannot last forever because plants cannot repair tissue damage or grow in this state.
Freezing is the other risk associated with extremely cold temperatures and is destructive for plants.
When the temperature drops to the freezing point, water crystalizes into ice. If you have ever left a bottle of water in the freezer, you know that ice expands after crystallizing.
The combination of sharp water crystals and expansion raptures plant cells. That explains why frozen plants become mushy and discolored.
How Cactus Plants Adapt to Freezing Winter Temperatures
Fortunately, not all plants are affected by cold. Cactus is a good example.
Cactus plants adapt in several ways to survive during winter, and regulating water is the reason behind all these adaptations.
Cacti usually go dormant during winter when temperatures tend to drop below freezing point. They reduce their cellular activity and stop growing, which allows them to survive on minimal water.
This is among the best adaptations of most desert plants, but also one that prevents cactus plants from dying when frost covers the ground.
When a plant has less water, it is less likely to crystalize due to freezing.
The low water content means other compounds in the plant cells are abnormally concentrated. The high concentration makes them work as a natural antifreeze, thus protecting the cactus.
The cactus could move water into the interstitial spaces between cells if the water level fails to go low enough to trigger this natural antifreeze.
Even if bigger crystals form here, they cannot harm the plant’s cells. Certain proteins found on the cell surface help repel those large crystals.
These adaptations are only partially failsafe, but their impact is impressive. Some cacti species can withstand temperatures below -30°F.
Normally, plants can’t endure such frigid conditions for long, but the hardy cultivars won’t be deterred by one or two freezing nights in the middle of winter from regenerating when the warm weather sets in again.
What Species of Cactus Pants Can Freeze?
Despite having a reputation for thriving in hot climates, some cactus species grow naturally in colder northern regions. Some cactus types are even native to Canada. Here are some of the cold-resilient cacti species:
Prairie hedgehog cactus
These little mounded cacti, native to the Great Plains and American Rockies, are hardy and attractive.
They can withstand any winter conditions but thrive better when covered with snow or mulch during colder months.
Fishhook barrel cactus
This species is unique because it can endure extremely high and low temperatures.
It grows in arid regions of the southern United States and northern Mexico, where daytime and nighttime temperatures vary considerably. Water moderately for optimum growth.
Texas barrel cactus
Texas barrel cactus resembles a bird’s nest made of thorns because protruding spines cover it.
It is mostly found in the Chihuahuan Desert and can withstand freezing up to 5°F. Temperatures below this can damage the plant.
Santa Rita prickly pear
Prickly pears come in different cold-hardy species, with the Santa Rita being one of the most common.
When not in the active growing phase or just mildly stressed, its pads turn a spectacular dark purple that adds color to the landscape all year round.
Although it is frost-hardy, Santa Rita can grow up to six feet tall, making it difficult to protect when cold weather approaches.
Eastern prickly pear
This cactus species is native to the United States and often found in the central and eastern states.
It is widely picked for food, like many other prickly pear cactus plants, since the pads and the fruits are edible.
However, the eastern prickly pear shrivels as temperatures drop, eventually lying flat on the ground. It comes back to life during spring.
How to Protect Cactus from Winter Burn Damage
Water less frequently
Help your cactus plants gradually adapt to the cold weather as temperatures drop. One way to do this is watering your plants less often, down to once every six weeks for most species.
Reducing watering frequency encourages cacti to enter dormancy, enabling them to survive through winter.
Shelter your cactus from cold air
Avoid waiting until the frost is severe to protect your cactus plants from the cold air. If your plant is small and potted, you can move it to a sheltered location, like behind a wall or away from strong winds.
Old furniture is another alternative you can use to protect your cactus. You can place a chair over your cactus to help trap some of the heat.
If your cactus is small, you can turn plastic containers upside down over the plant but leave some space for air to enter.
Use mulch or stones
Sometimes, the soil loses its heat faster as the weather cools. Fortunately, you can protect your cactus by covering the ground with materials to help retain the heat.
Some darker stone varieties are excellent for trapping the soil’s heat. Black lava or brown and red rocks can help retain the warmth in the soil, depending on the environment.
You can also use mulch to cover the soil as an alternative to stones. Mulch will keep your cactus comfortable by retaining heat.
Avoid using too much mulch because it might trap moisture and cause your cactus plants to rot since they cannot tolerate excess moisture.
Move your cactus indoors
It could be better to move your cactus indoors if you reside in an extremely cold climate.
But when doing this, be careful not to cause shock to your cactus by changing the temperature, light, or humidity abruptly because this might affect its normal adaptation process.
When moving your cactus indoors, place it in a spot with adequate sunlight or add a cactus-specific grow light to your plant room.
Also, ensure that no dust or obstructions are on the plant’s surface so that it can absorb enough sunlight.
Remember to adjust the room’s temperature and humidity to match the outdoor weather conditions.
Make a frost blanket
This is a quick and effective technique for protecting your cactus from freezing. You can do this in various ways.
There are high-quality, special frost blankets that retain heat in the air layer surrounding the cactus. You can also use plastic sheets, burlap, and other materials.
A frost cloth, especially white, allows sunlight to pass through, and burlap allows airflow. However, you should leave space for air if using a plastic sheet.
The most important thing is to ensure the blanket does not touch the cactus in any way.
The heat produced this way comes from the layer of trapped air, so if the material touches your plant, it might cause a drop in temperature and create room for frost damage.
Use a sturdy object like a chair to support the blanket and prevent it from shifting. You may need to use several layers of cloth if where you are is extremely cold.
How to Revive a Frozen Cactus
Even after doing all this, your cactus may still suffer winter burn damage. Or perhaps your cactus got damaged by the frost because you had no idea how to protect it.
Either way, you can still revive it, so there’s no cause for alarm.
When frost harms your cactus, you notice mushy tissue around the damaged parts. These damaged parts turn white at first. Do nothing at this point and wait for the cactus to repair itself.
The damaged parts will soon turn purple and eventually black. If it turns black, that means the tissue is damaged beyond repair.
At this point, prune the cactus and remove all damaged black areas to prevent further damage.
Cactus plants are highly adaptable to survive extremely hot and cold temperatures. But if you live in areas prone to freezing temperatures, you can protect your cactus plants from winter burn damage by following the simple techniques outlined above.
Last update on 2023-10-05 / Affiliate links / Images from Amazon Product Advertising API