What is the best potting mix for container gardening? Selecting the right soils not easy! Offers abound, and consumers can quickly lose the basics and usefulness of the soil. Not all potting soil is created equal, far from it! Plants deserve special attention and it is for their proper development that it is necessary to make the right choice. Potting soil is a decomposition product of organic matter or soil mixed with decomposed animal or plant matter. Each plant, each plant evolves in its own environment with different growing conditions. The quality of the soil must therefore be adapted to each of the product families to allow them to adapt quickly to their new growing medium.
Compost must be able to supply plants with nutrients, mainly minerals, and water. He must also breathe, allowing oxygen and other gases to circulate around the roots. Finally, the physical structure of the soil is decisive for allowing good rooting.
Thus, the differentiating elements will be the ability to retain water, to circulate the air, to provide the nutrients necessary for the plants, and the pH level of the mixture.
Do not confuse potting soil, a growing medium, with compost resulting from the decomposition of organic matter, which should not be used pure, but as a fertilizer.
Avoid potting soil made up of peat and composted bark, sometimes with plant crushing residue. Rather coarse, they dry quickly, are difficult to rehydrate, compact themselves and plants do not find enough nutrients.
Prefer specialized “ready-to-use” products offered in bags: soil for roses, soil for bamboos, soil for citrus fruits and Mediterranean plants, soil for containers and planters, soil for trees and shrubs ??.
Characteristics of a good soil
Good soil is a growing medium allowing plants to settle well in their new environment. It is sufficiently ventilated and provides the water essential for plant development. You should know that:
– The ability to regularly supply water to plants is measured by water retention.
A growing medium rich in organic matter (compost, blond peat ??) easily retains water.
– Mineral materials such as clay or pozzolana (porous volcanic rock) allow easy and quick rewetting after a period of drying out.
– The aeration of the soil, facilitating the growth of the roots, is provided by the composted bark, the pozzolana, or the cocoa fiber.
– Finally, the organic matter, provided by the compost, provides the mineral elements essential for the rapid start of plant growth.
The pH level of the soil
The pH of the soil has an influence on the assimilation of nutrients and trace elements by a plant.
Most trace elements dissolve best under moderately acidic conditions (pH around 6.5) but a large proportion of plants grow happily in any normal soil, which can vary from slightly acidic to slightly alkaline.
A neutral pH is around 7.
A pH below 7 is acidic and perfectly suited to heather earth plants for which the pH is between 4.5 and 5.5.
A pH greater than 7.5 is suitable for plants that require soil with a basic tendency for their development ( lavender, boxwood ??).
Aeration and water retention
It is often the soils rich in organic matter which is the most favorable to water retention.
These materials allow the soil to regularly provide water to the plants.
For growing in pots and to compensate for the small volume of the pots, the potting mixes must be able to store a certain amount of water, a bit like sponges. Minerals, such as clay or pozzolan, allow easy and rapid absorption after a period of drying out.
The water retention capacity is therefore essential for fertility, the roots drawing their nourishment in the form of diluted mineral salts. However, the earth must not turn into a quagmire, aeration being necessary for the oxygenation of the roots.
As much as the suffocation of the roots is dangerous for the plant, the lack of water in summer can be just as fatal if it is insufficiently watered while cultivated in a poorly absorbent substrate. The most important thing when choosing a substrate is therefore to find a balance between aeration and water retention.
To improve the aeration of your soil, we can advise you to mix it with clay balls.
The best potting mix for container gardening is depended on the plants to be planted
Mediterranean plants and citrus compost :
It must be light, flexible, permeable, sufficiently retain water, and facilitate soil drainage. Good soil for citrus fruits and Mediterranean plants promotes recovery and growth, increases fruiting and resistance to disease.
Soil for roses:
At the end of the season, it is still possible to plant rustic roses in pots. To do this, it is advisable to use quality soil to promote the vigorous rooting of newly established plants and stimulate the growth of those already in place.
Good soil for roses and flowering shrubs improves seed germination. It must be light, flexible, permeable, sufficiently retain water and facilitate soil drainage and avoid settling during planting.
Soil for containers and planters:
Good soil for containers and planters should allow abundant and lasting flowering of all indoor flowering plants, but also promote the development of rootlets for all flowering shrubs and plants in containers and promote growth and flowering.
It is very important that the substrate is well-draining because bamboos do not support spongy soils. The soil must be fertile, humus, cool. The PH will be located around 7 (neutral ground).
If bamboo likes wet soil, it hates having its feet in water all the time. The soil must therefore be draining with sufficient space for the drainage of residual water.
Soil for trees and shrubs:
The soil for trees and shrubs promotes growth and resumption of flowering. It is specially designed to provide the nutrients required by trees. It is rich in organic matter and provides excellent aeration and drainage while enhancing nutrient retention in your plants. It can be used for all flower and shrub planting, topdressing, and lawn renovation. It will also promote the development of rootlets.
This species of the earth is composed of silica, lime carbonate, hummus, or potting soil. It comes from the decomposition of plants. It is found in places where heather has grown abundantly and naturally for many years. It is composed of the debris of this heather, reduced to the state of potting soil and fine sand.
Heather earth plants like acidic soils and cannot stand the presence of limestone. Ex: azaleas, heather, camellias, hydrangeas, rhododendrons …
To be used for repotting in pots, tubs, and planting in the ground.
It is recommended to change the soil every year for two reasons in particular:
– overtime, the plants end up using up the minerals contained in the substrate.
– disease-carrying agents brought in by rain, air or movement can settle in the soil.
It is also better not to make potting soil yourself with soil from the garden. Often too dense, it can also contain pathogens and weeds harmful to the development of potted plants. I hope this article about the best potting mix for container gardening is useful for you.