Good soil is the basic ingredient every garden needs to showcase beautiful and bountiful plants. A soil is judged by the texture. Soil can be clay, sand or silt, or a wonderful balance of the three, called loam. If the garden soil is not the type needed by the plants that are envisioned for the location, improvements can be made with organic matter. These improvements not only change the texture of the soil, but pH levels can be adjusted, nutrients added, and the ability of the soil to store and release the nutrients enhanced.
Soil with the largest particles is sand. The particles, with their sharp edges, can easily be seen. Sand allows water to pass easily and does not compact, but the moisture is not retained for long. Working organic materials into soil that is made up mostly of sand will bind the particles. The improved soil mixture will hold onto moisture and nutrients longer, while still giving the root systems the ability to spread out, and absorb water and nutrients from a large area. Columbines and snapdragons are examples of plants that prefer well-drained, sandy soil.
The size of silt particles falls between the size of sand and clay. The texture of silt is smooth, without the sharp edges of sand. Wet silt doen't feel sticky like clay. Puddles often form on the top of silt soils and become compacted, making it harder for roots to become established and spread. The soil can be broken up to allow for proper drainage, but without other improvements, compaction and drainage issues will reoccur. Verbena and zinnias do well in soils made up mostly of silt.
Clay soil holds moisture and nutrients. If the moist soil sticks to the garden shovel, it likely has high clay content. When the soil is squeezed to release the water content, clay soil will stick together and can be formed into a tight ball. Even though clay soil has poor aeration and holds excess water, it also holds onto fertilizer. To improve the drainage of heavy clay soil, work topsoil and compost into it. Hollyhocks and geraniums are amont the plants that will tolerate clay soil.
Rich looking loam soil is composed of a mixture of clay or silt, sand and organic matter, and is the soil type gardeners work to achieve. When the moisture is squeezed from loam, it will form a ball, but the ball will easily crumble. Loam will absorb and retain moisture depending on whether is sand- or clay-based. Clay- and silt-based soil will retain moisture longer than sand-based soil. Loam soil promotes a healthy garden that needs less watering and other maintenance. Loam also helps gardens survive drought. A garden site of loam will make almost any plant thrive.