Cacti are not part of the typical landscape in this country. However, they are often welcome guests in our homes and gardens. They delight with their unusual growth and bright flowers. The variety of varieties knows almost no limits. The passion for collecting quickly ignited. These undemanding plants require little care. But do they love icy winters outdoors? After all, they are known as desert dwellers.
Can cacti tolerate frost?
In our imagination, cacti and desert are inseparable. There, where the sun burns tirelessly and the rain is extremely rare. Where frost is an unknown word. True, some types of cactus actually come from these inhospitable sandy areas, but not all of them. For example, there are leaf cacti that prefer tropical rainforests. However, they also don't know any frost in their homeland. Both desert cacti and the rainforest specimens cannot tolerate sub-zero temperatures, which are an integral part of winter here. They belong in the bucket, and definitely in the house in winter.
But there are still a few survivors from the cactus family that grow in the high Andes or the mountains of North America. These mountain species are used to cold and are therefore frost hardy. We also allow them to grow outside all year round.
Winter-hardy varieties
In the large cactus family there are some beautiful varieties that cope well with frost. Even temperatures down to minus 25 degrees don't bother these desert dwellers much. Provided, of course, that your requirements in terms of location and care are optimally met at all times. The hardy species include hedgehog cacti (Echinocereus), ball cacti (Escobaria) and prickly pear cacti (Opuntia). The following varieties are particularly recommended in this country:
- Echinocereus adustus
- Echinocereus baileyi
- Echinocereus caespitosus
- Echinocereus coccineus
- Echinocereus inermis
- Escobaria missouriensis
- Echinocereus viridiflorus
- Escobaria arizonica
- Escobaria orcuttii
- Escobaria sneedii
- Escobaria vivipara
- Opuntia phaeacantha
- Opuntia fragilis
- Opuntia rhodantha
- Cylindropuntia imbricata (columnar)
variety selection
Overwintering cacti outdoors can only be successful if they are frost-hardy varieties. All other types of cactus would not survive icy winters outside. Even in mild, frost-free winters, caution is advised. Even if the cactus survives the winter, at least growth and flower production will suffer. For anyone who does not have suitable winter quarters, hardy cactus varieties are a must. If you don't know which varieties are growing in your area, you should find out in good time before the onset of winter. For example, you could ask specialist retailers or do research online. In the future, only buy cacti that are hardy for outdoor use.
Note:
When buying new cacti, be sure to pay attention to their “previous life”. Hardy cactus varieties that only live in greenhouses are not hardy enough. The statement “hardy” on the label is of very little use.
Selection of location
For a hardy cactus to survive the cold winter really well, winter hardiness is of course an important criterion. In addition, the prickly desert dweller needs good living conditions all year round in order to develop into a strong, resilient plant. Only then will it be able to withstand the cold and enter the new season unscathed. Good care also includes the optimal location.
- sunny
- protected from wind and rain
- Water must be able to drain easily
- if applicable create a drainage layer
- Planting on a slope also prevents moisture
- a small hill can also be created
Cacti don't like wet feet, then they rot quickly. Waterlogging is particularly dangerous in winter because the frozen water damages the roots.
Tip:
Subsequent location optimization is definitely possible. Either the cactus is transplanted to a more suitable location. Or a drainage layer can be added later.
Rain protection
Some cactus varieties must not be left unprotected from the rain in winter, otherwise they will lose their winter hardiness. These include:
- Hedgehog columnar cactus hybrids
- like octacanthus and viridiflorus
- Cacti from the genus Gymnocalycium
- Crossing Opuntia and Escobaria wild species
These cacti can be planted outdoors and remain there all year round. However, they need a protective roof over their heads that will keep most of the rain away from them.
- A location under a canopy is ideal
- alternatively also a superstructure
- Wooden posts form the supporting framework
- Greenhouse film is ideal as a cover
- two pages should remain open
- this ensures sufficient air exchange
Cover
In autumn, most native plant species are covered with a layer of brushwood or mulch. Cacti, however, require a lot of light even in winter, which is why they should not be covered. Anything that keeps the root area wet should also be avoided, such as dried plant debris nearby. However, snow as a cover is welcome. It protects the cactus from extreme cold and moisture. A layer of snow can safely remain there. Even if the cactus underneath disappears completely. Only condensation can cause problems. It is therefore important that this can always drain easily.
Water reduction
Cacti store plenty of water in their trunks, and sometimes also in their leaves. This is important for the survival of cacti in the warm season. In winter, however, too much water can have catastrophic effects. Water freezes at zero degrees and expands. The bulging cacti would freeze so quickly. Therefore, the water supply must be adjusted early to the approaching winter.
- Start reducing water in August
- water gradually less
- don’t water anymore from September
With each passing day, the cacti will look more and more shriveled and will eventually hang flat on the ground. Now it's time: Don't panic! And don't reach for the watering can! Even if your beloved cacti are not a pretty sight, there is no need to worry. The pitiful appearance is not a result of thirst for water. Rather, it is a successful strategy for surviving the cold winter without suffering from frostbite. In spring, as soon as the temperatures noticeably rise again, the water supply can be resumed. The cacti recover surprisingly quickly from the winter stresses. The new water application irons the wrinkled skin smooth again.
Note:
To protect against frost, cacti store s alt and other substances and thus lower the freezing point. The deposited substances cause the cacti to discolor. This brownish discoloration is not harmful and will disappear on its own in spring.
Fertilizer
The cacti have a kind of hibernation during the cold season. During this time growth stops completely. This must be taken into account when fertilizing.
- Stop fertilizing from autumn
- do not fertilize at all during the entire rest period
- don't start fertilizing again until spring
Note:
By the way, cacti are special plants that usually grow slowly. They need a special fertilizer that meets their needs.
Overwintering cacti in pots
Cacti and terracotta pots are a particularly decorative combination. That's why cacti are often planted in it, but also in all other possible pots. When autumn comes to an end, the potted plants are moved to frost-proof quarters. For most plants, including most types of cactus, this is a life-saving measure. But not for the hardy cacti. For these types of cacti, the cold period is essential for he althy growth. Afterwards the flowering is even more lush and beautiful. If you put them in warm winter quarters, these cacti would suffer.
- hardy cacti can/must overwinter outdoors
- but need protection
- Stop fertilizing and watering
- set up protected from rain and wind
- under a canopy
- Place the bucket on Styrofoam and wrap it with fleece
- Do not wrap the cactus as it needs light
- the protection can be removed again in spring
Tip:
Don't bring the buckets into the house, even in severe frost. The cacti could start to grow in the warmth. This leads to weak and pale shoots. There is also a risk of frostbite if you put it out again, as your adaptation to the winter cold is weakened by the warm “excursion”.
