Cacti – care, propagation & overwintering

• Spherical cacti
• Columnar cacti
• Exuberant and group-forming cacti
• Hanging cacti
• Bulbous or jointed cacti
• Climbing cacti
• Leafy cacti and some more.

Cacti are exotic plants, which certainly contributes to their popularity. Their appearance is very different from other indoor plants. In addition, you can plant several different varieties together if they have the same requirements. What other houseplants does this work with?

Cacti are often confused with euphorbia. They look similar, but have very different needs when it comes to care. They can be distinguished by the plant sap. Euphorbias are spurge plants. The sap is white, milky. The flowers of the euphorbia are also smaller.

Cacti are quite undemanding and most are also very easy to care for. In principle, anyone, even people without a green thumb, can cultivate cacti at home. There are a few things to consider, but nothing complicated.

Care of the cacti

Not all cacti have the same care requirements. This is mainly due to where they have their natural range. In some things they are very similar, in others they are quite different. Some conditions can be generalized, others need to be evaluated specifically. We have put together a lot of general and specific tips here. Continue reading!

location

The location requirements of cacti are quite different. Many of them, especially young plants, grow in their home in the shade of the surrounding plants and therefore prefer partially shaded locations. However, all cactus species need a certain amount of light for photosynthesis.
A distinction is also made between summer and winter quarters. If cacti are to bloom, you have to accommodate them differently.

• Cacti need a bright spot, almost all right by the window.
• An east or west window is ideal. Most species like that.
• Only a few, on the other hand, tolerate the blazing midday sun of a south-facing window.
• Desert cacti need full sun
• Rainforest cacti prefer shade or partial shade.
• In summer, the cottages like to be outside, but protected from the rain.
• Here, too, east or west sides are ideal.
• Without rain protection is usually not a problem, as long as the summer is not too cool and too wet.
• When clearing out the winter quarters, the cacti must first be slowly accustomed to the sun again!!!

plant substrate

All cacti require a well drained substrate that allows for good drainage and air circulation. There is special cactus soil on the market. It usually consists of equal parts sterilized clay, crushed peat and coarse-grained sand, mixed with a slow-release fertilizer. You can use these. It is not ideal because peat is good at storing water. Depending on the type of cactus, additions may be necessary. Normal potting soil is not suitable, it contains too much nitrogen fertilizer.

You can also mix cactus soil yourself. This is often the better choice.

• Add about ¼ of coarse aquarium sand (grain size 2 to 3 mm) to standard cactus soil.
• This mixture is suitable for most of the cacti.
• For cacti that like an acidic substrate, add some rhododendron earth.
• For those who like a mineral-rich substrate, you mainly use aquarium sand (half), plus a quarter of cactus soil and lavalite and clay.

plant

If you plant several cacti together, you have to make sure that they all have the same care requirements. Newly acquired plants should be repotted immediately. Since cacti are prone to root pests, check the root for infestation. Otherwise only repot every two to three years! The best time to do this is at the end of the dormant period, from early March to early May.

• Pots made of plastic or clay are ideal
• Clay has the advantage that the material releases too much water through the outer walls.
• However, the vessels dry out severely in high heat and suck all the water out of the ground. This is unfavorable for cacti during the growing season.
• The vessels should be neither too big nor too small. A space of 1 cm between the cactus and the edge of the pot is ideal.
• Flat flower bowls and balcony boxes are also suitable.
• There is always drainage at the bottom, which protects the roots from waterlogging.
• Wear thick gloves when planting! Beware of the spikes.
• Don’t pour right away. Better to wait two weeks. Before a cactus can absorb water, new roots must first grow.
• Cacti with beet roots need narrow and deep vessels.
• Cacti with fine roots like shallow bowls.

temperature and humidity

Almost all cacti do well with room temperatures in summer and a minimum temperature of 5 °C in winter. However, there are many species that require slightly different temperatures during the dormant phase in winter.

• Desert cacti in winter 8 to 10 °C
• Species from extremely hot areas 15 °C.
• In spring, a daily high of 22 to 27 °C encourages flowering and growth of most desert cacti
• In the case of rainforest cacti, the temperatures before and during flowering should never drop below 10 °C. Because of the high air humidity required, they should be regularly sprayed with lukewarm rainwater from above!

watering and fertilizing

You have to be very careful with the watering. Too much moisture leads to black rot. Without fertilizer, on the other hand, growth is delayed and the flowers look rather weak.

• During the growing season until mid-autumn, water early in the morning or late in the evening.
• Pour Penetrating!
• Then the soil has to dry out properly before you add water again.
• On hot and dry days, you can simulate dew formation by gently spraying with water in the evening.
• From October the watering doses will be reduced.
• During the dormant period in winter, almost all cacti can do without water.
• Soil from plants that are kept in warm, centrally heated rooms all year round should be moistened occasionally
• Jungle and rain forest cacti must be kept moist all year round
• At the beginning of spring (end of March) it is watered again. Water very sparingly at first, increase watering
• The amount and frequency of watering is increased until summer
• During the holiday season, the cacti manage without water. They then use their memory.
• Fertilize about every 4 weeks during the growing season.
• Only use diluted fertilizer with nitrogen, potassium, potash and important trace elements
• Nitrogen (N) = 1
• Phosphor (P) =2
• Potassium (K) = 2
• You can use regular cactus fertilizer
• Flower fertilizer contains too much nitrogen

To cut

Cacti are not pruned regularly like other plants. But if they get too big, many of them can easily be shortened. Bulky, spherical cacti don’t like pruning. Columns and limb cacti usually have no problem with it.

• Sharp and clean tools are important!
• Always disinfect!
• Hold cactus with kitchen tongs!
• Only cut at the narrowest point!
• Cut straight!
• Sprinkle the interface with charcoal powder!
• The separated part can usually be used for propagation.

hibernate

Cacti need a rest period in order to form flowers. This is at least 16 weeks. They should not grow during this time and put all their energy into flowering. Therefore it is important not to water the plants! This only works at temperatures between 4 °C and a maximum of 12 °C. At this temperature, hardly any water evaporates.

• A frost-proof, unheated room is ideal. It doesn’t have to be overly bright.
• A cool basement room, which is illuminated with fluorescent tubes mounted 20 cm above the plants, is also practical.
• A warm place to hibernate is unfavorable.
• The plant cannot produce flowers.
• Without water, she struggles to survive.
• With water it grows instead of blooming.

multiply

Most cacti can easily be propagated by cuttings or side shoots. Sowing is also possible

propagation by cuttings

• To obtain a cutting, part of the plant body is cut off at the narrowest point with a sharp knife.
• The best time for pruning is from mid-spring to mid-summer.
• Slightly sharpen the cutting at the cutting point.
• Leave the cutting in a warm, dry place until the wound has healed. This takes at least 2 weeks, but can also be months.
• Store the cutting in the planting position.
• Then it is planted in well-drained soil, in coarse sand, perlite or vermiculite.
• Pour extremely carefully. There are no roots yet that can absorb water.

sowing

• Sow seeds in small, shallow containers, preferably plastic.
• watering!
• Cover with glass!
• Always keep the potting soil slightly moist!
• Temperatures between 21 and 32 °C
• Protect the seedling from the blazing sun!

Side rung (Kindel)

• Kindel, which already form roots on the mother plant, are ideal for propagation.
• You separate them from the mother plant, preferably by turning them carefully.

Diseases

Unfortunately, cacti are quite often attacked by fungal spores. This is often due to too much moisture or a weakened plant. A cactus infected with fungal pathogens can often no longer be saved. That is why prevention is particularly important.
prevention

• Absolutely avoid moisture in connection with cool temperatures!
• Ventilation is important!
• Compost soil often contains fungal spores!
• Avoid injury to the plant. Fungal spores can penetrate there.
• Viral and bacterial diseases also occur. But they are rare.

pests

Cacti are also attacked by pests. This is unfavorable, as the plants often react very badly to pesticides. Beneficial insects are much more suitable for combating them. Reading and washing up are also good alternatives.

• Spider mites – tiny yellowish to reddish-brown pests that are difficult to detect. Cacti first appear pale, later turning yellowish or brown. Spider mites form spider webs, which become visible when they are lightly sprayed with water. Spider mites like low humidity. So the plants are properly misted with water, packed in an airtight plastic bag and everything is sealed for days. After a week repeat again for the second generation pests.
• Mealybugs and mealybugs – recognizable by the cottony white webs and the honeydew, the sticky excretions. Mechanical removal is best, i.e. carefully remove the white deposits with a toothpick! A magnifying glass is ideal. You have to check for weeks and rework if necessary! Lacewing larvae or Australian ladybirds are natural enemies.
• Root lice – can only be seen when repotting. You can see webs and cocoons, similar to mealybugs. If infested, all soil must be removed. The root is carefully washed. However, the wax excretions of the lice are water-repellent. So being too careful is not a good thing either. Then carefully pot again.

Conclusion
Cacti are fascinating plants. Although I’m more of a friend of euphorbia, I also have a cactus and although I hardly notice it, it blooms every year. It is in a pot with an irrigation system, so it takes its own water in the summer when it needs it. In winter it stays dry. The location is south, but not directly in the window, but behind a curtain. Fertilizers are rare and irregular. The shoots (hanging cactus) are over a meter long and there is no end in sight. A very decorative and easy-care plant. I can recommend it to anyone who doesn’t want to overdo it with plant care.