What Is the Best Soil for Growing Flowers? A Detailed Guide to Flower Potting Mix Techniques

Spring has come around again, and flowers, grass and trees have all begun new growth. Quite a few people have also started planting flowers and plants, so what is the best soil for growing flowers? Many people still do not know, so today the editor will introduce the various soils used for growing flowers.

1. Peat soil

Peat soil, also known as turf soil, was formed in the Quaternary period and contains large amounts of thoroughly decomposed plant material, humus and some minerals. Peat soil has an organic matter content as high as 70%-80% and humic acid of 40%-50%. Internally, peat soil has a fibrous structure; it is loose, porous and airy, and can effectively store nutrients and water. Generally, unless the peat soil you use is labeled for acid-loving plants, it has been artificially adjusted to a pH value of (5.5-6.5), making it suitable for growing the vast majority of plants.

2. Perlite

Perlite is a natural aluminum silicate compound, made by crushing magmatic rock and firing it at a high temperature of over 1000 degrees, producing an expanded material with a porous structure. It has the advantages of being clean, light in texture, and free of pathogens and insect eggs. At the same time, perlite has good drainage and air permeability and is widely used to improve soil aeration. It is a good substrate for ecological horticultural cultivation. Peat soil is cheap and easy to use; its drawback is that because it is light in texture, it easily floats everywhere during mixing, and it also tends to float up when watering.

3. Vermiculite

Vermiculite is a layered magnesium-containing hydrous aluminum silicate, similar in appearance to mica. It is the product of the weathering and alteration of natural minerals such as biotite, occurring in block, flake and granular forms. Its interlayer water molecules volatilize when heated at high temperature, and its volume increases 18-25 times, turning golden yellow or silvery white. Vermiculite has a relatively high layer charge, so it has a relatively high cation exchange capacity and strong cation exchange adsorption ability (that is, vermiculite has a certain fertilizer-retaining property and can release certain nutrient elements, whereas perlite does not have this characteristic). Vermiculite is commonly used in horticultural potting mixes; added to the medium, it can loosen the soil, improve aeration and retain water and fertilizer. It is an important component of lightweight soilless horticultural media. Used for covering seeds after sowing, it provides good moisture retention, and combined with seedling peat it is the best combination for cuttings and sowing.

4. Akadama soil

Akadama soil is a cultivation medium formed from volcanic ash, volcanic rock and pumice left over from ancient volcanic eruptions in Japan, and is known as the “all-purpose soil”; it is a loose, airy volcanic mud, sterile, with a slightly acidic pH value, and has good water retention and drainage. It is suitable for cultivating various succulents, orchids, Acorus gramineus and other higher plants. Akadama soil is a very convenient and clean high-quality planting material; it has all the advantages of perlite and none of its drawbacks, and can be mixed with other soils for planting.

5. Maifan stone

Maifan stone is a volcanic rock formed after volcanic eruptions. It is clean, sterile, free of impurities and contains large amounts of mineral elements (potassium, phosphorus, rare trace elements, etc.). It is a mineral with many functions and can increase beneficial trace elements in the soil. It is hard in texture and not easily broken, and has strong adsorption and ion exchange properties. It effectively adsorbs harmful substances in the medium and water, releases beneficial elements, promotes root growth, has a very good function of purifying water quality, can effectively promote plant growth, and makes plants more upright and richer in form. At the same time, Maifan stone is also a good soil conditioner that activates minerals and can be reused.

6. Rainbow stone

Rainbow stone is made by mixing media such as pumice, zeolite, volcanic stone and slow-release fertilizer. It is a new type of inorganic mineral mixed medium with good air permeability as well as good water-holding and fertilizer-retaining capacity. It is an excellent product for succulent soil improvement and potting media, and can be used alone, or for top dressing or mixing.

7. Pine bark

Pine bark is a new type of organic cultivation medium made from pine bark as the raw material, processed through crushing, composting and fermentation and other steps. It has good air permeability, retains water and fertilizer, and has a high organic matter content. It is cheap and easy to use, and there is no trouble with it floating everywhere. Because it is a natural product, after decomposition by microorganisms it can also provide nutrients to plants. Pine bark can be used to grow orchids, Dendrobium officinale, succulents and epiphytic plants, and can also be spread on the surface of the soil for decoration, water retention and weed prevention. Placed at the bottom of a flower pot, it helps with drainage, water flow and aeration.

8. Diatomaceous earth

Diatomaceous earth is an excellent substrate component, and its water absorption and water retention performance are both superior to vermiculite and perlite. Using it as a base soil, its water absorption, water retention and fertilizer retention capacity are all stronger than other substrate formulas. For cultivating succulents, orchids and other flowers, the physiological and morphological indicators are better, and root rot is less likely. Diatomaceous earth powder or granules can be mixed into the planting material, or scattered on the surface of the potting soil. Mix the powder into the soil and scatter the granules on the surface of the potting soil; this can prevent and kill fungus gnat larvae and root mealybugs.

9. Expanded clay pebbles

Expanded clay pebbles used for growing flowers are made by firing at high temperature. They are porous, airy, sterile, pollution-free, light in weight, easy to carry, high in surface strength, not easily broken, reusable, and have good water-retaining and fertilizer-retaining performance. The internal pores of the pebbles are filled with air when there is no moisture; when there is sufficient moisture, they absorb part of the water while still maintaining part of the gas space. When there is insufficient moisture around the roots, the moisture inside the pebbles diffuses through their surface into the pores between the pebbles, for the roots to absorb and to maintain the air humidity around the roots. They are widely used for growing hydroponic plants and for bottom drainage.

The above is the editor's introduction to the soil used for growing flowers. Different types of plants have different requirements for soil, so when using soil you should decide according to the specific variety.