One of the keys to having beautiful indoor plants that are healthy and full of life is to choose the best potting soil for each plant. Potting soil is a product of decomposition of organic matter, or regular soil mixed with decomposed animal or vegetable matter. Each plant evolves in a clean environment with different growing conditions. The quality of the soil must, therefore, be adapted to each species of plants to allow them to quickly adapt to their new growing environment.
Here are our tips to choose the right potting soil for your indoor plants:
How to choose a good potting soil?
The potting soil is the growing support on which plants grow. It is composed of 2 main types of ingredients:
- Solid materials (like pebbles or sand) which ensure good rooting of plants as well as good hydration and aeration of their roots since they provide spaces in which water and air can infiltrate.
- Organic matter (such as midden or compost), which is the essential nutrient for plant health and growth.
Indoor plants generally require a sufficiently rich substrate to ensure their development in a reduced volume of soil; you should also choose a well-draining potting soil to avoid stagnation of water which leads to the degradation and rotting of their roots. The water retention capacity is therefore crucial for fertility, the roots drawing their food in the form of dilute mineral salts. However, the potting soil should not turn into a swamp, aeration being necessary for the oxygenation of the roots. The most important thing when choosing a substrate for your indoor plants is therefore to find a balance between aeration and water retention.
The pH of the soil has an influence on the assimilation of nutrients and trace elements by a plant. Most trace elements dissolve better under moderately acidic conditions (pH about 6.5) but a large proportion of the plants grows happily in any normal soil, which can range from slightly acidic to slightly alkaline.
However, not all indoor plants have the same nutritional requirements, so finding the ideal potting soil composition can be difficult. To simplify your task, there are many different types of potting soil, specially developed to meet the needs of each type of plant.
It is recommended to change the potting soil every year for two reasons in particular:
– Over time, the plants eventually exhaust the minerals contained in the substrate.
– Agents carrying diseases brought by water, air or shifting can settle in the soil.
It is also preferable not to make potting soil yourself with the soil from the garden; often too dense, it can also contain pathogens and weeds harmful to the development of your indoor plants.
Best potting soil for Succulents and Cacti
The succulents and cacti are qualified as resistant plants as they flourish on poor and dry grounds. The special cacti compost, therefore, has a composition rich in solid ingredients to ensure perfect drainage.
The use of universal potting soil is also possible by adding two-thirds of coarse sand or clay balls (these can eventually break, this will allow small roots to sink more easily into the support).
Cacti and succulents are more resistant to drought than excess water! Always wait until the substrate is completely dry before watering them.
Best potting soil for Orchids
Orchids are epiphytic plants that cling to trees to develop. Their roots have the ability to capture nutrients at the air level and therefore do not require support such as potting soil to grow. The special orchid potting soil is specially developed to imitate these growing conditions. It mainly consists of maritime pine bark mixed with peat, rock wool or even perlite.
Repotting orchids in a brand new potting soil is done every 2 to 3 years. Be careful not to choose a pot that is too large, the roots of these plants prefer to be cramped.
Best potting soil for herbs and flowers
For potting green plants (ficus, philodendron, palm tree …) or flowering plants (Cyclamen, Fuchsia, Begonia …), a universal potting soil is generally sufficient. It provides all the nutrients necessary for the proper development of your indoor plants and quickly rewets while ensuring good water draining.
The special indoor plants’ potting soil, enriched with fertilizers, is also an excellent substrate, both for planting and for repotting. If your plants are too developed to be repotted without risk, do a surfacing: remove as much old soil as possible and replace it with new soil.
Best potting soil for Bonsai
Bonsai trees are generally grown in flat pots containing a small volume of soil. The nutritional elements of the substrate are therefore quickly exhausted and potting is imperative for the health of your miniature tree or shrub.
When the roots threaten to invade the pot or come straight out, it’s time to repot your bonsai!
A good bonsai potting soil should be rich in nutrients and well ventilated to let the roots breathe and grow while retaining water to ensure proper hydration.
Choose a special – ready to use – bonsai potting soil. In addition to the organic matter necessary for good growth, these soils incorporate draining materials (sand, pozzolan, etc.) and water-retaining materials (clay).
Best potting soil for Carnivorous plants
Carnivorous plants are plants that thrive in very humid areas, where the substrate is poor in nutrients. Hence the fact that they have developed such a special nutrition system.
The ideal would be to pot them in a soil made up almost exclusively of blond peat. However, peat being a non-renewable resource, we advise you to use a special potting soil for carnivorous plants, consisting of blond peat, sphagnum and pozzolan.