Why cactus need a special soil, the best soil for cactus in pots and instructions for mixing yourself can be found here.
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Cacti (Cactaceae) are plants that one either loves at first glance or only appreciates with skeptical looks. But those who have given themselves to the love of cacti do everything so that the favorites on the windowsill lack nothing. Here the focus is not on the regular watering and fertilizing of the prickly plants, but on the soil in which the roots are embedded.
Because of their special requirements, special cactus soil is available in stores. The properties of this soil are suitable for most types of cacti. But if you have mixed the soil yourself, especially with unusual specimens, nothing comes close, because this way you can meet the very individual needs of the cactus species. We have the right recipes for you.
Properties and Peculiarities of Cactus Soil
Not only the exterior of cacti is unique, their demands on the soil and its composition are also something very special. This is because cacti belong to the family of succulents. That means they are adapted to locations where there is no water at least seasonally. Cacti easily overcome the dry spells by storing water and nutrients in their thickened trunks or leaves. Their roots are also adapted to the local, rather barren soils and spread out flat just below the surface of the earth. This provides information about the special demands that cacti place on their soil in pots. Therefore, special cactus and succulent soil is also offered in specialist shops. This soil should have the following properties.
Optimal properties of cactus soil
- Loose, for good water and air permeability and root penetration
- Retains moisture even after drying out completely
- Nutrient rich
Best Soil for Cactus in Pots: Buyer's Guide
When buying cactus soil, particular attention should be paid to its composition. This provides information about whether the substrate can also meet the above conditions. Humus should be included as a source of nutrients. Loam or clay creates a slightly acidic pH that most species of cacti are happy with. Sand loosens the structure of the earth and ensures good water drainage. Do not save on the substrate for your cactus, after all, the well-being of your prickly friend depends more on the structure of the soil than with other plants.
Bonsai Jack Succulent and Cactus Soil, for example, has proven itself. With a balanced dose of nutrients and a long-term stable soil structure, which includes particularly good permeability and drainage, this substrate offers an ideal basis for a healthy cactus plant.
Making Your Own Cactus Soil: Instructions and Recipe
If you prefer to use the personalized variant, you can simply mix your cactus substrate yourself. Mixing it yourself has the advantage that you can adapt the composition to the species. Cacti from desert regions such as Echniocactus, Astrophyllum and Lophophora prefer purely mineral substrates that are modeled on the barren, nutrient-poor soils of their home. They also prefer particularly good drainage properties:
- 3 parts clay (lightly grind)
- 2 parts perlite (2 – 8 mm)
- 2 parts of expanded clay (2 – 4 mm and broken) or expanded slate
- 2 parts lava gravel (2 – 4 mm) or pumice (2 – 4 mm)
- 1 part vermiculite
However, since not all species are adapted to extreme conditions, there are cacti that need a little more nutrients and water. Mineral-organic substrates are used here. These are more nutritious and better at storing water:
- 2 parts of potting soil
- 1 part silica sand
- ½ part of pumice
- ½ part perlite
The proportions of organic and mineral components can be adapted to the species, because there are species that prefer the organic content to a greater or lesser extent. Another advantage of self-mixed cactus soil is that the pH value can also be perfectly adapted to the species. With some species an individual adjustment is even necessary.
Note: Use high quality silica sand and not play sand. This usually has too high a calcium content and brings one or two pests with it.
For more in-depth article on the best type of soil for cactus, read “What kind of soil do cacti need“.
Repotting Cactus Soil
The substrate or soil in which the cacti are located should be replaced approximately every two to three years. The background is that the mineral aggregates gradually accumulate salt, which are caused by the watering water as well as by fertilizers. It is also recommended to supply freshly purchased cactus plants in a larger container with fresh and optimal soil. Unfortunately, many cacti from plant centers and DIY stores are only supplied with normal potting soil, which in the long run can damage the sensitive root system of the prickly plants.
Frequently Asked Questions
What is in cactus soil?
Like most plant soils, many cactus soils consist of organic and mineral components. Organic components are substances caused by the degradation or by waste products of plant, animal and microbial organisms. Often these are simply referred to as humus. Materials such as compost, animal manure or plant residues can increase the humus content in the soil.
On the other hand, there are mineral aggregates, which can have a direct influence on the structure, texture and physical properties of a soil or substrate. Some of these additives can, for example, have a positive effect on the water storage capacity or the pH value of the entire substrate, while others can be a valuable source of important trace minerals . The most common additives in the manufacture of cactus soil are:
- Expanded clay
- Expanded slate
- Quartz sand (silica sand)
- Lava gravel
- Pumice gravel and pumice sand
Occasionally, other additives such as brick chippings or biochar or charcoal are used.
Can you plant cactus in potting soil?
If you want your cactus to thrive, then it is not recommended to plant it in normal potting soil. The 5 reasons below are why potting soil is not a good choice:
- Potting soil tends to retain water. This increases the chance of rot in cacti.
- Potting soil contains too much organic matter. Cacti are not accustomed to such rich soils.
- Potting soil contains too much nutrients. These nutrients can burn or damage the cactus.
- Potting soil is often dense and compact. Cacti need well-aerated soil for the roots to grow and spread.
- Potting soil offers poor drainage. Cacti needs well-draining soil to reduce the risk of rot.