Potting soil is a mixture used to grow plants, herbs and vegetables in a contained garden

Garden

A garden is a planned space, usually outdoors, set aside for the display, cultivation, and enjoyment of plants and other forms of nature. The garden can incorporate both natural and man-made materials. The most common form today is known as a residential garden, but the term garden has...

 environment. The first recorded use of the term is from an 1861 issue of the American Agriculturist.

The most common ingredients used in potting soil are peat moss, composted bark and/or other plant materials, sand

Sand

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

, and perlite

Perlite

Perlite is an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian. It occurs naturally and has the unusual property of greatly expanding when heated sufficiently...

 (for drainage). Some potting soil mixtures contain particles of vermicompost

Vermicompost

Vermicompost is the product or process of composting utilizing various species of worms, usually red wigglers, white worms, and earthworms to create a heterogeneous mixture of decomposing vegetable or food waste, bedding materials, and vermicast...

, while other contain vermiculite

Vermiculite

Vermiculite is a natural mineral that expands with the application of heat. The expansion process is called exfoliation and it is routinely accomplished in purpose-designed commercial furnaces. Vermiculite is formed by weathering or hydrothermal alteration of biotite or phlogopite...

 for water retention. Most commercially available brands of potting soil have their pH fine-tuned with ground limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

, and some contain small amounts of fertilizer

Fertilizer

Fertilizer is any organic or inorganic material of natural or synthetic origin that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of crop yields are attributable to commercial fertilizer use...

 and slow-release nutrients. Despite its name, little or no soil

Soil

Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

 is used in potting soil because it is considered too heavy for growing houseplants.

Some plants require potting soil that are specific for their environment. For example, an African violet would grow better in potting soil containing extra peat moss while a cactus

Cactus

A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...

 would thrive in potting soil that contains material for sufficient drainage, most commonly perlite or sand. But potting soil is not ideal for all contained gardening. Insectivorous plants, such as the Venus flytrap

Venus Flytrap

The Venus Flytrap , Dionaea muscipula, is a carnivorous plant that catches and digests animal prey—mostly insects and arachnids. Its trapping structure is formed by the terminal portion of each of the plant's leaves and is triggered by tiny hairs on their inner surfaces...

 and the pitcher plant

Pitcher plant

Pitcher plants are carnivorous plants whose prey-trapping mechanism features a deep cavity filled with liquid known as a pitfall trap. It has been widely assumed that the various sorts of pitfall trap evolved from rolled leaves, with selection pressure favouring more deeply cupped leaves over...

, prefer nutrient-poor soils common to bogs and fens while water-based plants thrive in a heavier topsoil mix.

Commercially available potting soil is sterilized, in order to avoid the spread of weeds and plant-borne diseases. It is possible to reuse commercial potting soil, provided that the remnants of plant roots, fungus, weeds and insects are removed from the mixture through heating before new planting can take place. Packaged potting soil is sold in bags ranging from 5 to 50 lb (2.3 to 22.7 ).

As with garden soil, potting soil can attract insects. For example, the fungus gnat

Fungus gnat

Fungus gnats are small, dark, short-lived flies, of the families Sciaridae, Diadocidiidae, Ditomyiidae, Keroplatidae, Bolitophilidae and Mycetophilidae , sometimes placed in the superfamily Mycetophiloidea, whose larvae feed on plant roots or fungi and aid in the decomposition of organic matter...

 is often found around houseplants because it lays eggs in moist potting soil.

Legionella contamination

Infections dduis to potting mix have been reported in Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, the Netherlands, and the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

.

On June 13, 2000, the U.S. Centers for Disease Control and Prevention

Centers for Disease Control and Prevention

The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...

 (CDC) reported that a woman in Washington was hospitalized with pneumonia that was triggered by Legionella longbeachae,yah the bacterium associated with Legionnaires' Disease. The CDC also confirmed the presence of Legionella longbeachae in soil in Australia and Japan.

See also

• Compost
  Compost
  Compost is organic matter that has been decomposed and recycled as a fertilizer and soil amendment. Compost is a key ingredient in organic farming. At its most essential, the process of composting requires simply piling up waste outdoors and waiting for the materials to break down from anywhere...
  
  
• Mulch
  Mulch
  In agriculture and gardening, is a protective cover placed over the soil to retain moisture, reduce erosion, provide nutrients, and suppress weed growth and seed germination. Mulching in gardens and landscaping mimics the leaf cover that is found on forest floors....
  
  
• Good agricultural practice
• Container garden
  Container garden
  Container gardening is the practice of growing plants exclusively in containers instead of planting them in the ground. Pots, traditionally made of terracotta but now more commonly plastic, and windowboxes have been the most commonly seen. Small pots are commonly called flowerpots. In some cases,...
  
  
  • Category: Garden vases
  • Sub-Irrigated Planter
    Sub-Irrigated Planter
    Sub-irrigated planter is a generic name for a special type of planting box used in container gardening and commercial landscaping. A SIP is any method of watering plants where the water is introduced from the bottom, allowing the water to soak upwards to the plant through capillary action...