The Uses and Properties of Loam Soil

When growing a garden, you're initially at the mercy of whatever type of soil is indigenous to your location. Very few areas of the country, perhaps with the exception of the Great Plains, have naturally occurring loam soil. Loam soil is the soil with the most fertility, and is also the most suitable for growing garden food crops, flowers and roses. It is possible to improve clay or sandy soil with the addition of organic matter, such as peat moss, compost and well-rotted manure. This must be done over a period of several years to be effective, according to Purdue University Consumer Extension specialists. Counter-intuitively, sand added to a heavy clay soil will not improve its structure, especially if it is very heavy clay. Sand turns clay into concrete.

Properties

Loam soil is considered the ideal type of soil in which to grow vegetables, small garden fruits, flowers and roses. This is based on its composition--loam soil contains just the right amount of clay, silt, sand and organic matter to facilitate the growth of plants. It allows water to drain freely, but not too fast. It holds in moisture, but not too much. It allows air to penetrate the soil, which is beneficial to plant roots. The organic matter increases the soil's fertility, thereby growing healthier plants that produce crops in greater abundance than sandy or clay soils. Loam soil holds together when you squeeze a handful and the handful breaks apart when you poke it with your finger. Sandy soil will not hold together when a handful is squeezed. Clay soil will not break apart when you poke it with your finger after squeezing a handful.

Food Crops

Even under ideal climatic conditions with adequate rainfall and consistent sunshine, sandy or clay soil will not grow food crops with a higher yield than those grown in loam soil. Even under less than favorable weather conditions, crops grown in loam soil will still out-yield those grown in sandy or clay soil. The organic components that increase fertility, along with the well-draining yet moisture-retaining structure of loam soil, produce the healthiest plants. Healthy plants are better able to resist infestations by insects and infections by disease organisms than plants that are stressed by less-than-ideal soil conditions.

Flowers and Roses

Flowers--annual or perennial--and roses grow strong and produce copious blossoms when grown in rich, loamy soil. Some flowers, and most roses, will not grow in clay soil at all; this type of soil simply retains too much water for the plants' roots to breathe. Sandy soil doesn't hold enough water to adequately hydrate roses and most flowering plants, and they will struggle to produce flowers. Loam soil has just the right balance of large sandy particles which helps water drain without puddling, yet enough microscopic clay particles to hold enough moisture for the roots. As with food crops, flowers and roses will grow, if coddled, in sandy or clay soils, but they are much more healthy and produce many more flowers if grown in rich, loam soil.