The plants that are grown in regular pots or in any other type of containers have only a limited amount of earth to use for growing. As a plus the extensive watering destroys the nutrients inside the soil.
This is why the soil preparation for these plants must be done according to the type of the plant and its natural physical needs. The basic nutrients and the pH of the soil are also specific for each species.
It is very important that the soil in the pots should keep its porosity and water absorption capacity for as long as possible. For this purpose you will have to place a sandy layer on the bottom of the pot so that the soil will be drained and not become compact.
The porosity of the soil must be very high for azalea, ferns, orchids and epiphytes. The African violets, begonias, gardenias and podocarpus also like a high soil porosity, while camellias, hortensias and poinsettias prefer the average porosity. The “juicy plants”, ivy, hibiscus and geraniums do well in a more compact soil.
All apartment plants like a slightly acid soil with a pH between 5 and 6.5. Such a soil is a combination of dirt and good flower compost. Such a combination will help the soil stay light for a longer time and will keep a constant humidity.
Most of the flowers we buy in pots are originally planted in a soil composition where the special flower compost covers at least 1/3 of the entire quantity. The ferns, the orchids, the bromelias and many others cannot do without the special soil composition. So when you move them to a new pot you must respect the soil recipe.
However, a small group of plants like heavier, clay based soil, able to retain the nutritive elements and pass them to the plants without putting the plants in danger. The oleander, asparagus and sanseviera grow beautifully in this type of soil.
The soil mixtures are many and varied so far combinations go. However some of them can replace others with the same good results. When purchasing a plant from the florist shop, make sure you inquire about the type of soil you will need in case you want to move it.
Most florist shops have readymade specialized soil combinations, labeled as fitting certain species of plants. All you have to do is ask and get the right one.