Improving Sandy Soil: What It Is and How to Amend Sandy Soil

Ed Wike
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What is Sandy Soil?

Sandy soil is just about as bad as you can get for gardening. It looks, feels, and behaves like sand. In many cases, it’s identified as such. This is because of the two principal components that make up the soil. The first is silt, which is mainly sand that is 100% smaller than sand. The second is clay, which is mostly rock that is less than 100% smaller than sand.

Like a beach where the sand is mostly made of silt, there is nothing living in the soil. As a growing medium, it is entirely void of nutrient and organic matter, so nothing germinates and grows on the surface, at the very least nothing that you want.

The challenge with sandy soil is that it drains water very quickly. If that drainage isn’t halted by dense material or otherwise altered, it becomes an issue with just about any type of landscape garden. The drainage usually becomes an issue during a rainy spell before the seedling or young plant has time to develop the anchor roots to maintain a firm hold.

Once the moisture and the soil has drained into the soil below, the plant is now off balance. Roots will begin to grow in a downward spiral, compromising the plant’s ability to hold itself up to grow.

How to Tell if You Have Sandy Soil

Soil texture is commonly used to differentiate between sandy soil and other types of soil. Textural classifications are based upon several parameters, but the most predominant distinguishing characteristic of sandy soils is the presence of a high percentage of sand-sized particles.

Sandy soils have particles ranging from very fine sand, to fine sand, to the larger sand and can be further subdivided based on the proportion of these particle sizes. Sandy soils tend to drain easily, whereas clay soils hold more water and are considered to be heavier. The various sedimentary particles found in most sandy soils include quartz, mica, and feldspar grains. Sandy soils are generally lacking in clay, which contributes to the structure, color, density, and composition of a given soil.

How to Improve Sandy Soils

Sandy soils are low in organic matter and nutrients. Some plants, such as many trees, require a high percentage of organic (carbon-rich) material in order to grow properly. These trees may grow, but they will not grow as large as they could, or could have, in a more fertile soil.

Water and air exchange in sandy soils is slow and is further impeded by the presence of a hardpan or pan lining the surface. Pans form when the clay particles in the soil become cemented by a layer of organic matter, and the water wicked into the soil does not leave. This can be caused by poor drainage or overwatering.

Some plants, particularly deep-rooted ones, need a porous soil to grow effectively.

These trees and shrubs do not thrive in sandy soils. Sandy soils hold plant nutrients, nutritional water, and oxygen poorly, in that order.

Here's a great idea that will help you amend your sandy soil and help ensure your plants are getting what they need.

Don't overlook the obvious. Organically rich compost makes sandy soils better. Adding compost is like adding a layer of fertile topsoil to sandy soils. It's a great way to make poor soil better.

But do not add more than twenty percent organic matter at one time.

If the soil is very sandy, add mulch.

Work In Lots Of Rich Organic Materials

Sandy soil might be easy to work with, but it drains rapidly and it is low in nutrients. This is because sandy soil is made up of small particles that are unable to hold on to water or fertilizer. What it does hold on to are large amounts of sodium from salt that has blown onto it over the years. The easiest way to improve drainage is to add lots of organic materials.

Organic soil improvers are a great way to make your soil looser and more nutritious. When you add organic matter to your sandy soil, you increase its bulk and shrink its particle size. This prevents water from running straight through your soil and gets nutrients and water right where they are needed.

The best organic soil improvers are things like manure, coffee grounds, grass clippings, and leaves. You can also add other things like leaf mold (leaves accumulated into a thick layer

Of the forest floor), pumice, peat moss, and composted kitchen scraps.

Layer On The Mulch

Many people believe that sand is just sand. However, that's not always the case. Exposed to wind and the elements, sand may be scooped up and end up in different areas. If the soil lacks organic matter and bacteria sand may not hold nutrients.

To improve sandy soil in your garden, mulch the area.

Mulch is any organic material or fabric placed on bare soil to keep grass and weeds down.

Using a variety of mulch materials specifically made for garden use will help you fight the effects of sand. Regardless of the type of mulch you choose, use about two inches of the material. Don't spread a thin layer of mulch. Otherwise the mulch will only help suppress weeds, not in enriching the soil.

You can also add organic matter to sandy soil.

A layer of compost or mulch can help improve any sandy soil.

Mulch and compost are more effective done together, for they work together to keep in moisture, improve drainage, and also add organic matter.

Together, they will help your sandy soil to hold nutrients and the water needed for roots to grow.

A layer of compost or mulch will keep the sandy soil from flying away, all while feeding it.

You can add your organic matter to the sand, but it's best to lay it over the soil.

Grow Cover Crops

Cover crops are typically plants that are cultivated either before or after the main crop harvest is obtained. A cover crop can be planted simply for the purpose of controlling weeds and providing ground cover, or it can be grown for the dual purpose of giving fertility back to soil that has been depleted as a result of the main crop.

Sandy soils are just that – sandy. A sandy soil is composed partly of sand and partly of silt. It is very loose and free draining.

The easiest way to improve sandy soil is to add organic matter to it. The organic matter will help to improve the texture, aeration, and fertility of the soil.

Using a living cover crop is the best, most organic way to improve sandy soil. The roots of the plants will aerate the soil, and they increase the fertility. At the end of the growing season that will be added to the soil then, as well as the cover crop biomass itself.

How to Fertilize Sandy Soil

Amending sandy soil is important for plants that have limited root structures. In fact, the problem is so prevalent that a lot of gardeners will suffer through a couple of years of growing just to build up the dirt and make a good ground base.

Because the nutrients are available to the plants, the growing process will probably feel easy. Then watch out! The plants are going to think they're in an over-crowded jungle and go into competition mode!

The problem is that you are witnessing the competition for nutrients at its weakest form. Hundreds of years from now, your grandchildren are going to wish their garden was in an over-crowded jungle. When that happens, my advice is that you toss the garden and start over.

The cycle continues until the plants cover themselves and you can't tell any of them apart. Then you'll have to dig up the competition for whatever reason, and it is then, that you'll gleefully notice that no one plant grew much larger than a few inches.

So the point is that sand is bad for your plants because it doesn't offer the nutrients, but it is good for their health because they're not fighting.

Sandy soils do have good qualities, too. Plants will establish their roots easier in sandy soil, and it won't take long to finish off the competition, at which point the plants grow pretty fast.

How to Water Sandy Soil

Sandy soil is soil that has a relatively high amount of sand, compared to the amount of clay and other components. Sandy soil is fertile, and so it has a high amount of nutrients and organic matter. However, sandy soil is also less porous than other types of soil, and this makes it more difficult for water to penetrate. Additionally, sandy soil drains very quickly, meaning that once the rain stops, it can take a long time for the water in the soil to filter down to the roots. As you might expect, this can make it difficult for plants to grow in sandy soil. It's possible to improve a sandy soil to make it more like other types of soil. If you're a gardener, this is going to make life easier for you, as it will make it easier for you to start plants from seeds and get roots established. It also means that you'll be able to water your plants effectively, as the soil will be easier for water to penetrate.

Best Vegetables for Sandy Soils

So what is sandy soil? Sandy soils have a lot of free time because they are composed of large particles. That said, a sandy soil is a nice place for your vegetable garden.

Sandy soils are easy to work with, when during the winter you must do nothing to the soil. A sunny site will help your plants to make the most of your sandy soil.