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Garden Soil Basics

Soil is one of the most important aspects of any vegetable garden for a variety of reasons, and thankfully, it is something you have a considerable amount of control over. Soil is the foundation of your garden and it supplies the plants with primary and secondary nutrients, retains moisture, and provides the air circulation they need to reach maturity. If you want to grow a thriving vegetable garden it is essential to make every possible effort to improve the quality of your soil. Keep in mind that most gardeners start out with less than ideal soil and getting it to ideal conditions will happen over time. This article is designed to show novice gardeners how to take the steps necessary to put together a bountiful vegetable garden.

The Structure of Soil

Soil is made up of four basic parts which include soil particles, organic matter, water, and air. It is necessary to have a healthy balance of these 4 factors to ensure that your soil can support your garden.

  • Soil particles  - are can be defined as the minerals, or simply dirt, that has been broken down into fine pieces. A good soil will be rich in primary nutrients (also known as macro nutrients) which include nitrogen, phosphorus, and potassium. Most soil will be lacking these minerals initially,  especially if you are gardening near other large trees.
  • Organic matter -  is simply dead and decaying organisms within the soil, which is mostly comprised of dead plant matter.
  • Air Flow -  Can be defined as the ability of oxygen and carbon dioxide to penetrate the soil. Fairly loose soil will do a great job of allowing air to flow freely through the soil. Highly compacted or clay soil will not allow air to flow freely and may not support a garden.
  • Moisture – is the ability of the soil to hold and drain soil. When water penetrates the soil it will cause the essential nutrients to dissolve which will allow the plants roots to absorb them. However, you do not want the soil to become oversaturated with water because it will restrict air flow in the soil, which is essential for the plant’s growth. You can avoid oversaturation by watering less or improving the drainage.

Look at the Weeds to Determine Soil Type

Sometimes you can simply look that weeds growing near your garden to get an indication of the type of soil that exists there. Just like vegetables, weeds need specific soil conditions to grow well. A quick examination of the weeks is a quick and easy way to start testing your soil.

Weeds that require nutrient rich soil include: ground ivy, lamb's quarters, pigweed, and burdock.

Weeds that indicate poorly drained soil include curly dock, hedge bindweed, sheep sorrel, and smartweed.

The Four Basic Types of Soil—Sand, Clay, Silt, and Loamy

Soil Particle Size Chart

Sand

Sandy soil is made up of… well, sand. It does not have a solid structure and will fall apart easily, which can tend to cause problems in vegetable gardens. Most notably, sandy soil does not hold water very well because the soil particles are solid and deflect water. This type of soil is almost guaranteed to be lacking in the nutrients needed to grow a successful garden. However, sandy soil can be gradually improved over time by simply adding organic matter to the soil at least once per year. A hefty dose of organic compost, manure, or just dead leaves will do wonders for improving the nutrient quality. The organic matter will help the soil retain water more effectively and allow your plants roots to absorb the much needed nutrients.

Sandy Garden Soil

Clay

There are several disadvantages to working with clay soil, and it is the most difficult soil vegetable gardeners have to work with. The drainage of clay soil is often very poor, which can cause the vegetables to get oversaturated. In addition, the temperature of clay soil is low which will cause slowed growth in most vegetable varieties. On the bright side, you will not need to water clay soil as frequently and it is usually rich in primary and secondary nutrients. It is highly recommend to add organic compost, manure, or just dead leaves to the soil to improve drainage and air circulation. Within a couple years it is very likely to turn clay soil into an optimum vegetable garden soil. When you’re first starting out with clay soil, you might consider starting your vegetables in containers. You can spend the first year getting the soil in better shape, then transplant your vegetables in the next growing season.

Clay Garden Soil

Silt

Silt is uncommon in most areas, but you may find it if your garden is near a river or some other body of water. Silt is made up of particles that are smaller than sand, but larger than clay. The drainage quality of silt is excellent, but it lacks the nutrients needed to grow a thriving garden. You can improve silt soil by mixing in organic materials, such as compost. After adding organic materials you should have excellent starting soil to start your garden.  

Loamy

Loamy soil is the type of soil that gardeners strive to create. Loamy soil can be defined as a nutrient rich blend of the clay, sand, and silt that provides adequate drainage. Very few gardeners are lucky enough to start their gardens with loamy soil, but it can be achieved after a few years of adding organic materials. In any case, loamy soil will still need to be with organic materials and fertilizers at least once per year. Vegetable plants will suck the nutrients out of the soil and it will require regular maintenance to keep your garden in top form.

More Garden Soil Information

Understanding Soil Nutrients

Testing Garden Soil

Best Vegetables to Grow based on Soil pH Level

How to Improve Soil Texture