Loamy Soil

What Is Loamy Soil, And Why Is It Important?


One can either say loam soil or loamy soil. Both terms mean the same thing. Technically, loamy is an adjective, and loam is a soil type, and would therefore be a descriptive noun. Whenever directions for planting a garden are given, 9 times out of 10 it is recommended to place plants or seeds in a loamy soil. Whenever it’s claimed that a given type of plant can do well in almost any kind of soil, there’s quite often a qualifier – a loamy soil is preferable.


A Good Loam Contains Nutrients


Just what is loam? We often think of it as being regular garden soil to which some compost has been added. That’s not too far off the mark, since one of the characteristics of loan is that it always contains a certain amount of organic material. If adding organic matter was all there was necessary to produce loam, all we would need to have when putting in a vegetable or flower garden would be a few sacks of compost or manure to add to the dirt. In fact, that is sometimes the case. Peat moss works too, as peat moss is organic matter.


A Good Loam Provides Drainage


It’s obvious then that loam provides a good source of nutrients for whatever is being planted, which would suggest a combination of sand and peat moss, or heavy clay and chicken manure, would be just fine. Those two combinations however could not be called loam. Sand does not hold moisture, and even if peat moss is added, the combination still would not hold moisture well. The soil would certainly drain well, a characteristic most plants find necessary, but it would also tend to dry out quickly. At the other extreme, a clay-manure mixture might drain poorly, a condition under which many plants cannot survive. What we want is a soil that contains some organic material, a soil that drains well but still holds moisture, and a soil that allows roots to spread and to breathe.


The Three Main Soil Types


Soil may be divided into three categories or types, sandy soil, silt, and clay, and a loamy soil will be made up of some of each type. The sand in loam, while it does not hold water, provides aeration. It is the sand in soil that allows a plant’s roots to spread and to breathe. Clay consists of much finer particles than sand, and it is the clay in soil that retains water, and helps keep the soil moist. The problem with clay is that its particles are so fine that they tend to compact easily, and when that happens water cannot drain away. If there is too much clay in soil, there will be insufficient aeration.


Silt is somewhat of a happy medium between sand and clay, as its particles are smaller than those of sand and larger than those of clay. Ideally, a soil consisting purely of silt might make a good garden soil, except for one thing, a lack of nutrients.


Buy Topsoil, Or Make Your Own


When planting a garden, one will usually be faced with one of three situations. The first, and the best, is when the existing soil is already nice and loamy, the second is that when it is so poor that it would be better to order a few yards of topsoil, which could be expensive, and the third is to make one’s own loamy soil by working in whatever needs to be added to the existing soil. It’s not necessary to find an exact combination, of sand, clay, and silt. Don’t worry about the silt, there will always be some present in any event. A good loam can really be said to consist of sand, clay, and organic matter.


It’s How It Feels That Counts


How much of each to make a good loam? A good answer would be “enough”. A good loam will feel “loamy” which means it will feel a bit crumbly. It may form tiny clumps, but it won’t compact all that easily, nor does it blow away with the slightest breeze, even though it should feel “light”. In most gardens, a nice loam can be produced simply by adding to existing soil enough peat moss, manure, or compost to achieve the right consistency. If the soil contains lots of clay, it may be necessary to add some sand. Adding only sand to a clay soil is never a good idea. If sand is required to improve aeration and drainage, it should always be added in conjunction with organic matter. Achieving a truly fine loamy garden soil may take up to several years, and is best accomplished by adding a little organic material each year.


A good potting soil is somewhat of a different story, and it may be best to look for a recipe that gives more or less the quantities of each component the soil is to consist of. The main difference between a good potting soil and a good loam for the garden is when making a potting soil, the soil needs to be heated to kill off existing bacteria, bacteria an indoors plant might find harmful.