Which potting soil should I choose for my houseplants?

It's not easy for an orchid or a Monstera to move from the rainforest to your living room. To help the little one adapt to your apartment, choosing the right indoor plant potting soil is just as important as exposure and watering. But with so many products on the shelves of garden centers and on the web, how do you know what to choose?

Let's start with the obvious: for a potted plant, potting soil is a growing medium. It replaces the soil in which the plant grows naturally. It must perform the same functions:

Potting soil is composed of organic matter (sphagnum moss, peat, green waste, compost, etc.). Manufacturers add ingredients to improve its properties. Mineral materials (sand, perlite or vermiculite) lighten the soil and promote drainage, while fertilizers stimulate growth and flowering.

Deprived of the resources provided by rain or the natural environment, houseplants need a rich substrate. The potting soil must also compensate for over- or under-watering by regulating the water content in the pot.

For potted plants, avoid universal potting soil. Contrary to its name, this product is not suitable for all plants. It is used in the garden to loosen or modify soil structure. Its enriched version, horticultural potting soil, is also used for outdoor cultivation, for vegetable gardening or flowering plants, rather than indoors.

Most of the species we repot at home are happy in potting soil for green plants and houseplants. This is true of ficus, philodendron, Sansevieria and Monstera. It's also ideal for flowering plants such as anthurium andreanum, Saintpaulia and moon Flower.

But some houseplants, like orchids, have specific requirements for their growth. As epiphytes, they take their nourishment not from the soil, but from the air. They need aerated, organic matter-free soil. Products made from bark and plant fibers are available on the market under the name of orchid potting soil. Orchid nurseries make and sell mixes adapted to each variety (Phalaenopsis, Cymbidium, Cambria...). Some even offer delivery to your door.

With your Crassula, Haworthia, heart chain, Saguaro, ball cactus, euphorbia or Christmas cactus, it's all about drainage. Potting soils for cacti and succulents combine organic matter for nutrients and mineral matter to optimize water drainage. But their use isn't limited to succulents. They are ideal for potting Hoya or Peperomia.

In their small pots, bonsai can only rely on fertilizer and a limited amount of potting soil to grow. To meet their nutritional needs, manufacturers have developed products that optimally combine nutrients with water and gas circulation. This avoids the need for frequent repotting.

For other plants with more specific requirements, you may need to mix different products:Calathea or Alocasia appreciate repotting in a potting soil for green plants with sand or perlite.

Finally, you can adapt the potting soil not to the plant, but to its intended use. Potting soil for seedlings and cuttings is lighter and more aerated, favoring the development of young roots and seedlings.

Potting soil for flowering plants, citrus potting soil, organic potting soil, potting soil for carnivorous plants, potting soil for aromatic plants, potting soil for Mediterranean plants, heather soil... Faced with a profusion of references, are you afraid of making the wrong decision and ending up with ten liters of useless potting soil on your hands? Put your trust in the Monstera application. In our care sheets, we tell you which substrate to use for potting. We even explain how to improve the soil so that your green plant can flourish.

Now that you know which type of potting soil to choose, you'll have to choose between the various products on the market. But how can you be sure you're buying good quality potting soil?

Rather than looking at the price, check the PH of the potting soil. This number indicates the acidity of the soil. For potted plants, unless otherwise indicated, it's between 5.5 and 6.6.

Quality potting soil can be recognized by its appearance. Its color should be dark, dark brown, almost black. Its consistency should be fine and homogeneous. It should not contain too much undecomposed debris, or form a ball when handled. The final indication of product quality: it should be odorless.

But chances are you won't be able to open the bag to see, touch and smell the merchandise before use. So you'll have to read the label. It's easier than it sounds. First of all, check that the potting soil carries the NF U 44-551 label. This guarantees that the product complies with French legislation. The words "biologique" (organic) assure you that the fertilizers used in the mix comply with organic farming requirements.

Secondly, you need to know whether you're buying soil or... Water! The label indicates the dry matter, i.e. The weight of the product when the water is removed. The higher the dry matter content, the less water the potting soil contains. Next, look at the organic matter content of the potting soil. This is what binds nutrients and water, and enables plants to grow. Its rate is expressed either in relation to dry matter, or in relation to the bag as a whole.

If you're hesitating between two brands of potting soil for your Areca palm, compare the weight of dry matter and the rate of organic matter to determine the most nourishing product for your houseplants.

Still can't decide? Determine the composition of the substrate. Fertilizer, coconut fiber, sphagnum moss, peat moss, clay... Does the product you have in your hands meet your plant's needs?

If the answer is no, and you can't find what you're looking for anywhere, all you have to do is make your own potting soil for houseplants. One third sand, 20% heather soil, two grams of coconut fibre, ten millilitres of fertilizer... Some plant-addicts turn into Walter White when it's time to repot. How about you? Share your best recipes in the comments!