To remove excess water from the soil when planting indoor plants, drainage is used. This is done so that the root system can breathe. Drainage is necessary for most indoor crops, with the rare exception of especially moisture-loving species.
If watering is too intense, air exchange is disrupted, harmful microorganisms appear in an airless environment, which has a very bad effect on the roots and growth of the entire plant. In such conditions, the plant withers quickly and may die. Therefore, special holes are made in the pots for the outflow of excess water, and a drainage layer is laid out on the bottom.
Drainage holes
The presence of drainage helps create optimal conditions for the growth and development of indoor plants, they need it to the same extent as proper lighting, watering or fertilization. The quality of drainage depends on the size, shape and material of the pot, as well as the number of drainage holes and their size. In ceramic pots, there is often only one large hole, which is enough, plastic ones are produced without holes at all, and you need to pierce the bottom yourself in the right amount.
Distinguish between fast and moderate drainage. For cacti, orchids, and succulents, a small multi-hole pot filled with substrate with coarse sand, crushed bricks, or others is a better choice to drain water quickly.
Plants that prefer moist soil are planted in a pot with fewer holes and a dense substrate.
Regardless of the size and number of drainage holes, care must be taken to ensure that they are not clogged with soil or root suckers. To prevent clogging, you can lay out large pebbles in a small layer on the bottom. If the holes are still clogged, this can be seen by the water content in the sump immediately after watering. If it is very little or not at all, the drain holes are clogged. You need to put the pot on its side and clean them with a stick. If the holes are regularly clogged, it is better to transplant the plant into another container to avoid root rot.
Some plant species have such a developed root system that it fills the entire space of the pot. In this case, the drainage layer may not be required at all, or it must be very thin. Through the drainage holes, the roots will be clearly visible, and you can easily trace their condition. Instead of drainage, you can use pebbles poured into the pot pan.
Drainage
Having picked up a pot with the necessary holes, you should decide on the type of drainage. The main requirements for it are the ability to pass water and air, low chemical activity. In addition, it should not grow moldy and rot.
The choice of such material is quite wide: expanded clay, crushed stone, charcoal, pebbles, synthetic winterizer, ceramic shards and polystyrene. The thickness of the drainage layer of any kind for pots with holes with a diameter of 0.5-1 cm, if the holes are smaller or not there - 3-5 cm.The soil is added on top, in which the plant is planted.
Drainage types
Expanded clay drainage
One of the common materials used by flower growers is expanded clay. It can be bought at a specialty store that sells plants and related products. Expanded clay is a building material and serves as insulation and sound absorber. It is made of clay, environmentally friendly and has good hygroscopicity.
On sale you can find expanded clay with different sizes of granules - they are large, medium and small. The large size is only suitable for large flowerpots or pots, the small one can get stuck in the drainage holes, so it is optimal to use medium-sized granules with a diameter of up to 20 mm. For very small pots, you can take expanded clay sand, granules up to 5 mm in diameter, it is also suitable as a soil baking powder.
The advantages of expanded clay in floriculture are lightness, the ability to absorb moisture and release it as needed, without letting the soil dry out. Some manufacturers impregnate expanded clay with microelements useful for plants, using its properties. The service life of expanded clay is 5-6 years, after which it collapses, and the drainage must be replaced.
Drainage ceramic
Broken pottery can be used as drainage by placing a few shards on the bottom of the pot with the convex side up. Then a small layer of sand is added, for a larger pot it can be up to 5 cm. Then soil is poured and the plant is planted. The shards should be taken not too large, so that sand does not fall under them, and does not clog the holes at the bottom.
Styrofoam drainage
Waste foam packaging can also serve as drainage. This material has all the necessary qualities - lightweight, moisture resistant, not susceptible to mold. But you need to use it with caution, as plant roots can grow into it, which can be easily damaged during transplantation.
Gravel or crushed stone
They have all the properties for good soil drainage - strength and hygroscopicity, but they do not keep heat well, so it is recommended to place the pots on the south or east side. The disadvantage is their considerable weight, which will make the already difficult flower containers heavier.
Broken brick
It is recommended to grind it before use so that the sharp edges do not damage the roots. Natural material with properties similar to expanded clay.
What should not be used as drainage?
The use of organic materials such as egg shells, tree bark, nutshells is not recommended. They are susceptible to mold and decay, negatively affect the acid composition of the soil and can lead to a number of indoor plant diseases or even death.
It is undesirable to use sand as drainage, both fine and coarse. It clogs the drainage holes, which leads to rotting of the root system. When using river pebbles, you need to wash off the sand from it.
Particularly unsuitable marble chips, when interacting with water, the soil greatly changes the acid composition and becomes sharply alkaline.
