The soil environment provides essential water and nutrients needed for a plant’s growth and overall health. A soil’s texture plays a significant role in its ability to deliver these vital elements to plant structures, though plant type also influences how these materials are received. As a result, some plants may fair better in sand than potted soil and vice versa.
According to the University of Connecticut, a soil environment’s basic functions include providing sufficient support for plant stems, branches and leaves, as well as delivering water and nutrients throughout the plant’s structure. To do this, a soil must be dense enough to support the plant while at the same time it should allow necessary drainage processes to reach the plant’s root system. With all the different plant varieties, sizes vary and water and nutrient requirements can vary from plant to plant. When deciding between sand versus potting soil, the needs of the plant and the structure of the soil can help determine which type of soil environment will best meet the needs of the plant.
Soil texture refers to the size and number of soil particles within a particular environment, according to the University of Illinois Extension. Sand, silt and clay make up the three basic textures found in most soil environments, though each type can appear in varying amounts. The largest particle sizes exist within sandy soils, which allows for ample water drainage to plant root systems. Clay soils contain small particles that tend to compact when exposed to water. This limits the soil’s ability to conduct water to plant roots. Silt textures contain a combination of sand and clay particles, allowing proper drainage and ample support for plant structures.
According to the University of Florida, the steady drainage capacities found in sandy soils can work well for plants, such as cactus, that require infrequent waterings. Unfortunately, this drainage capacity also affects the soil’s ability to hold onto needed minerals and nutrients. As a result, sandy soils contain little to no organic material, which can provide needed nutrients to most plant types. Because of their ability to drain water so quickly, sand environments tend to remain dry, which may not bode well for plants that require an ongoing source of moisture for growth and maintenance.
Potting Soil Features
The availability of water within a soil environment can directly impact a plant’s ability to carry out photosynthesis processes, which directly affect a plant’s growth potential. Plant types requiring ample organic materials and water supplies can benefit from the combination of sand, silt and clay mix found in potting soil mixes, according to the University of Connecticut. Commercial-grade mixes also contain organic materials designed to condition the soil as well as create a fertile growing environment. Many vegetable and flowering plants require a potting-soil type of environment for optimal growth.
According to the University of Connecticut, differences between potting soil and sand environments are also reflected in the soil’s overall pH balance. PH balance refers to a soil’s acidity versus alkalinity, and different plant types may prefer one type over the other. As sandy soils enable ample drainage, pH levels tend to range along the acidic side. Potting soil mixes--with their evenly balanced textures and organic materials--tend to have a more alkaline chemical composition. In terms of pH balance, the plant type can help determine whether a sandy or potting mix soil will best promote plant growth.