The Content Of The Article:
- Appearance and growth
- Location and ground
- Cacti overwinter
- Diseases and pests
Cacti, short for cactus plants (Cactaceae), are succulents, meaning they can store moisture in their tissues and survive even in periods of extreme drought. So-called stem succulents store the largest amount of water directly in their spherical, columnar or cylindrical main shoots. Root succulents, on the other hand, collect the water in their bulbous thickened roots. Cactuses of the genus Pereskia, for example, are among the leaf succulents that can store water in their thick-fleshed leaves.
Of course, cacti are found only on the American continent and here especially in the dry areas. Ideal conditions can be found in steppes, semi-deserts and deserts - and in tropical rainforests. There they grow as epiphytes, similar to orchids, wild on trees.
Appearance and growth
Depending on the growth form, the cactuses are subdivided into three subfamilies. The Pereskioideae are thorny, shrubby plants that frequently climb and are not unlike trees. They belong to the original cacti and have real, fleshy leaves. Although the Opuntioideae also have real leaves on the shoot axis, they are quickly thrown off. The flowers are always bowl-shaped. The Cactoideae form the most species-rich subgroup of the cactus plants. They no longer bear leaves and can vary greatly in shape and appearance.
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The most famous cactus species
Cephalocereus senilis, in German "Greisenhaupt", comes from Mexico. The dense white hair makes a cuddly impression, but underneath are pointed thorns
Euphorbia ingens, also called columnar cactus or cowboy cactus, actually belongs to the milkweed family. Although the plant is from Africa, it is the star in many Westerns
Echinocactus grusonii is also known as the "mother-in-law's seat". Its golden yellow thorns can be up to five centimeters long on large plants.
Schlumbergera, the Christmas cactus, belongs to the leaf cactus and is characterized more by its rich flowering from November to February, than by sharp thorns.
The Mammillaria native to Mexico comprise about 180 species. Together they have the spherical shape and the beautiful, colorful flowers.
The genus Echinopsis or "sea urchin cactus" needs a lot of sun and just as much water. For a rich flowering, the plants must be overwintered at about ten degrees.
So that not a drop of water is wasted, most cacti carry thorns instead of leaves. The vital evaporation takes place exclusively on the outer skin of the thickened trunks and shoots. With their thorns, the plants in deserts and other hostile areas protect themselves from hungry herbivores.
Location and ground
Cacti are very popular as easy-care and idiosyncratic houseplants worldwide. They need a very bright and well-ventilated location, but usually tolerate no drafts. Some species can also be kept outdoors. Robust as they are, cacti also survive in clay- and humus-rich substrates, but well-drained, mineral earth still prefers most of them. In the open air, the soil should ideally be slightly acidic (pH 5.5 to 6.5) and usually needs to be well prepared, as it must not be wetted in winter. Indoors, you can simply use special substrate for cacti from the specialized trade.
Prickly pears (Opuntia) grow compact when they get a lot of sun. Therefore, they like to spend the summer outside, in winter they are cool and do not pour
Basically, cactuses are extremely frugal plants. Dryness is no problem for them, in contrast to just about all other plants - wet already. Even too little light they tolerate only very bad, which is not surprising in their origin. For cactus care, it is therefore important to ensure that the location is as bright as possible and to comply with large casting distances. Cacti are best placed directly at the south window, in the bright winter garden or - in summer - outside on a sunny, rain and wind protected place. Pouring is done once and then not until the substrate is almost dried out. The following applies: the smaller the plants, the shorter the casting time. Large plants usually only need water every four to six weeks, small specimens on the windowsill once a week. Use only cactus fertilizer for fertilizing during the growth phase in summer.
Tip: Put on gloves to repot cacti or use a noodle or barbecue tongs! The small spines drill easily into the skin, then break off and cause unpleasant inflammations.
Cacti are not only individually, but also combined in bowls to their best advantage. Choose cacti with similar care claims
For those who are annoyed about having to graze in the autumn, they can grow hardy cacti. Many of the North American cactus species survive well in our winter temperatures. Garden parties are some species of Opuntia, for example Opuntia imbricata, fragilis, phaeacantha or polyacantha. Also species of the hedgehog cactus (Echinocereus coccineus or triglochidiatus) or representatives of the genus Escobaria (Escobaria missouriensis or sneedii) are hardy, but more sensitive to moisture than most Opuntia.
Optimal for garden cacti is a floor-warm, covered location for protection against waterlogging. The soil should be a mixture of potting soil, sand and expanded clay or lava. Garden cactuses can be planted all year round except during frosty weather. To be cast in the garden practically not at all. Attention: In winter, cacti look shriveled in the garden. They have stored less liquid as cold protection to increase the mineral concentration in the cell sap. From April, the appearance normalizes itself again.
Prickly pears (Opuntia) can grow up to ten meters, depending on the species. Their fruits are edible
It is very easy to sow cacti yourself: All you need is a small greenhouse with plastic cover. Particularly suitable for sowing are Mammillaria, Echinopsen or Rebutia species. Fill the box with cactus soil and sprinkle on top a thin layer of lavagrus against fungal infestation. Lightly squeeze the cactus seeds into the ground and pour rainwater into them. Soon the little green balls will appear. Once the first thorns form, the cover can be removed. Separate too close cactus children in extra pots. The miniature cacti can stand outside in a warm place in summer, but avoid the blazing midday sun! After two to three years, you can look forward to the first flowering.
The propagation of cuttings works very well in almost all species with segmented shoots such as the Opuntia. Simply cut off a segment with a sharp knife, let the interface dry for a few hours, and then place it in nutrient-poor potting soil. A film hood or a room greenhouse ensure that the engine does not dry out. If the air in the room is not too dry, you can even do without a cover. Only the soil should always be kept slightly moist.
The strawberry cactus (Echinocereus enneacanthus) is a special breed. It consists of a green base and an attached red or yellow cactus
Diseases and pests
Although their thorns protect cacti from most larger predators, they are not immune to small pests. Often, cacti are attacked by lice and lice, which feed on the cell sap of the plants. Under the dense hairiness of some cactus species, the pests can also hide very well.
Spider mites leave brown cork calluses on the plants. Root lice sometimes hide in the pot. If poured too often, cacti begin to rot from below and often a gray mold is added. Caution: Use chemical crop protection products even in room cacti only in exceptional cases, because many cacti are extremely sensitive to this. The best way to prevent sucking pests is to use beneficial insects such as lacewings or ladybirds.