In order to successfully grow cacti, there are 3 main environmental factors to consider – light, water and soil. Cactus soil is an important part of the plant care process. The first important question for beginners who decide to grow prickly plants is what kind of soil is suitable for cacti? We will look at this question in detail.
In order to get healthy and beautiful plants, it is extremely important to choose the optimal soil composition. There are quite a few options for creating such soil mixes, we suggest familiarizing ourselves with the most popular solutions for optimal cactus cultivation.
The role of cactus roots in desert living conditions
The root system of any plant plays a key role in its development.
Learning how the root system of a cactus has adapted to extreme conditions will tell us why we need to prepare soil that dries out quickly after watering.
The roots of different cactus species absorb and retain moisture in two ways:
- The outer layer of roots absorbs quickly and prevents moisture loss in the soil.
- Using an extensive system of shallow roots spreading in different directions from the plant. This maximizes water consumption from a large area.
Cactus roots are also capable of rapidly adapting to uneven periods of soil moisture. After moisture hits the ground, new roots sprout and the old roots begin to absorb moisture more intensively.
In times of drought, the old roots dry out and the sprouted roots fall away. This creates air pockets in the ground to help prevent the roots from losing moisture. The rate of water absorption by the root system of cacti is also very important to the existence of prickly plants, because any moisture that enters the desert soil evaporates quickly. The rare seasonal rains are short-lived, and cacti must make the most of this moisture.
The root system of cacti has evolved into a quick and efficient “collector” of moisture. But if there is too much water, the underground part of the plant begins to rot. This is especially common in home care when succulents are frequently watered and not allowed to dry out the soil. It’s not just the root system that gets damaged from this. The tissues of cacti that store water will also become saturated if the plant frequently absorbs moisture from the soil.
What are the soil requirements for cacti
Optimal soil mix for cacti should not be wet all the time, otherwise root rot will start and kill them. A good nutritious soil for your cactus should be easy to deplete. This is why all-purpose soil is not suitable for it.
It’s important to understand that each species has special preferences for soil composition. Therefore, you should understand a few important nuances before buying a soil mixture:
- Cacti have a preference for loose and ventilated soil;
- All desert plants require a slightly acidic substrate, and a pH of 5 to 6 is considered optimal;
- If you want to get blooms, you will need to add nutrients to the substrate;
- Do not use nitrogen-based fertilizers in the soil, since the plants will react very badly to them.
The soil should be low in organic matter and high in sand or gravel to replicate the environment in which cacti are normally found. Cactus roots like an airy, well-drained soil mixture that drains well and is easily moistened. Don’t forget the importance of transplanting plants immediately after purchase. Regardless of which pot the plant is in, the best soil for cacti is the one you personally mix. Often cacti don’t grow well in general purpose soil.
What soil is suitable for different groups of cacti
The cactus family is conventionally divided into two groups – common (growing in the desert) and epiphytic cacti (living in rainforests).
What are the soil requirements for desert cacti
Cacti are commonly referred to as desert plants and the conditions are quite harsh. It requires a soil mixture based on fine stone, sand, porous material to provide excellent drainage and aeration. Properly prepared soil should dry quickly after watering the plant and have a minimum of organic matter. The mix should also be able to meet the nutritional needs of the cactus. When you water a cactus, it takes all the water and nutrients it needs. Consequently, there is a need for well-drained soil so that it can get rid of excess moisture. This will prevent root rot and fungal infections.
What kind of soil is needed for epiphytic cacti
Epiphytic cactus species do not root in soil like many plants. They sprout on large branches in rainforests, using their roots to cling tightly to their “host.” Epiphytes need a well-draining environment with plenty of air space, as the roots will naturally be exposed to air. These cacti also need a nutrient medium of more organic matter, but their roots should not dry out completely, as their desert relatives do. The soil for these plants should consist mostly of organic matter – you can add peat moss to your epiphytic cactus substrate.
What ingredients should be in Cactus Soil
The simplest and most popular version of preparing a soil mixture is based on mineral substrates with the addition of gravel. Zeolite is very suitable, it is especially good as an additive to the soil mixture. Zeolite is able to slowly release macronutrients important to plants, such as potassium. This improves root health as moisture gradually evaporates. Plants in large pots with this substrate may not need to be replanted for a long time.
Often in soil mixes for cacti, sand is used to ensure good drainage. However, coarse-grained materials such as perlite and pumice are better at preventing soil compaction and promoting rapid air and moisture exchange. Perlite is inexpensive and widely available in garden centers, pumice (along with other types of lava rocks) retains its structure longer and is rich in trace elements.
If we talk about the proportions of how to make soil for cacti, it is optimal to use 10 parts gravel and 2 parts porous mineral. Here it is extremely important to avoid excessive moisture. An excellent porous material would be pumice.
Another option where you can plant cacti is Acadama, in other words, half-baked clay. The disadvantage is that after 2 years the composition breaks down, so regular replanting of crops will be required.
How to prepare soil for indoor cacti
Universal soil for cacti is not always suitable for the conditions in which these desert plants must grow. Therefore, you should approach the question of making a soil mixture on your own. Making soil for repotting cactus is easy enough.
We suggest familiarizing yourself with how to make soil for cacti, so that these succulent cultures will be most comfortable to grow. To prepare a mineral loose substrate, ordinary soil and a loosener are used. The latter will act as perlite, pumice, lava, stone chips.
Important! Do not use bulk wood chips, tree bark, avoid peat.
Pumice is an excellent volcanic rock that is quite porous. If you can not use pumice, then use substitutes – perlite, fine pebbles for growing algae, Zeolite.
The purpose of adding such components is to provide the soil mixture with minerals that will allow water to easily pass through the mixture, but leaving it “airy”.
Another component that can be used is coir (coconut fiber). It can be found wherever terrarium grounds are sold. It is quite fibrous and coarse raw material, while being slow to decompose. The main purpose of using coir is to help retain air and moisture, this will provide a good substrate structure. Since coir is sold in compressed brackets, it will need to be manually loosened.
A mineral loosener will also be needed. Any fine textured material will do.
You can easily check the texture of your soil. To do this, moisten it a little and squeeze it with your hand. If the mixture sticks together, you need to add a little more pumice or perlite. An optimal cactus potting soil mixture should be coarse and disintegrate when squeezed.
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