The Truth About Adding Sand To Your Garden Soil Pros and Cons

There is much helpful information on whether sand should be added to garden soil. After researching the topic, I’ve written this article to weigh the pros and cons.

You can add sand to garden soil, but it has to be mixed to specific proportions. If the soil and sand are mixed incorrectly, it results in denser, heavier soil. For clay soil to become sand and lighter, the soil must consist of fifty percent sand.

We will cover the possible benefits and disadvantages of doing such in the following sections, so read on.

Adding sand to your garden soil

If sand is added to garden soil in small amounts, it will make hardly any difference to the overall mixture. Ideally, the soil should have 50% pore space, and in clay soil, the pore spaces are tiny. Sandy soil, on the other hand, has larger pore spaces.

Mixing the sandy soil and clay soil causes the larger spaces of the sand to be compacted and filled in with the minute particles of clay, and the result is dense, heavier soil with a smaller pore space than either of the materials.

Essentially, all life depends upon the soil… There can be no life without soil and no soil without life; they have evolved together.

Dr. Charles E Kellogg, Soil Scientist and Chief of the USDA’s Bureau for Chemistry and Soils

For the soil to take on the properties of sand, the ratio of the two materials would need to be close to 50:50. This would be impractical and costly in many cases. Still, it is an excellent way to make your garden soil finer and lighter if you have a small garden space or patch of soil.

Clay soil and garden soil, what is the difference

We’ve been mentioning clay soil and garden soil a few times now, and we would like to take this chance to introduce them properly in this article.

Clay soil is considered one of the more prevalent soil types, especially in the United States, and it has tiny particles that allow it to be a very compact type of soil.

While they can hold many nutrients and water, using them to foster plant growth is not advisable. More about them is covered in detail in this article on clay soil and its usage for plant growth, which you can check here.

On the other hand, garden soil is another word for topsoil, contains good nutrients that are very productive for plant growth, especially when well taken care of and often aerated.

They are usually found at the first 2 to 8 inches of soil, and more about their descriptions are described in another article I wrote on garden soil and its components, linked here.

This article covers clay soil extensively and is often mentioned because it is often one of the most prevalent topsoil components. Hopefully, these explanations will lessen confusion throughout the article.

When & why you should add sand to garden soil

Sand can create air pockets, increasing aeration and drainage and generally loosening the soil. This is especially helpful for plants with fine wire roots, such as lettuce.

Essentially, you want to add sand to garden soil to improve drainage, make the mixture lighter, or stop the soil from clumping and being too compact.

Despite its good qualities, you can’t add sand to any soil.

Add sand only to compost and not to native soil.

Pure compost is generally the only type of soil to which you should add sand. Adding sand to native soils isn’t a good idea and can harm your garden.

When sand is used with clay, it will cause the soil to bind and become even more compact. The aeration will then be reduced, opposite to what we desire.

In years gone by, it was standard advice to add sand to garden soil to improve the consistency. As more has been learned about soil structures, textures, and the ways to improve these attributes, it has become clear that there are many more effective ways to help garden soil than adding sand.

Misconceptions about sand in connection to the soil

It’s a widespread misconception that sand is good at breaking up clay. I can see why people would come to this conclusion because the particle size of sand particles is much larger than clay particles. The issue isn’t with particle size, though.

Clay is technically an alkaline chemical bind that includes lime, and the bonded chemicals within the clay are impossible for the sand to break up.

As I mentioned above, and is very effective when used with pure compost. It is essential, however, to be aware of a few things. Because sand helps to improve drainage, a process called leeching can occur.

What is leeching, and what can it do to your soil?

Leeching is when the water pulls nutrients away from your plants. This occurs because most nutrients and minerals are water-soluble, although some exceptions exist. Potassium, phosphorus, and nitrogen can all be found in water-soluble forms.

When it rains or you water the garden, the water begins to pull the nutrients away from the plants.

The added sand into the soil has served its purpose in speeding up the drainage process, but simultaneously the plants have been deprived of nutrition due to the increase in leaching.

Thankfully, there is an easy way to combat this. Fertilizing one or two more times during the season will ensure abundant nutrients and minerals available to the plants. The leeching process won’t be as detrimental to their overall health.

If your soil is organic and nutrient-rich, you probably shouldn’t add sand, as it can exacerbate any existing issues. Pure compost, though, can be an effective way to improve the consistency and drainage properties.

When & why you shouldn’t add sand to garden soil

Now that we’ve established how sand could benefit our garden soil, let’s look at the reverse. In truth, adding sand to garden soil can be equally detrimental as beneficial, depending on the specific circumstance.

Sand minimizes the amount of moisture that the soil can hold. If the volume of sand and clay are equal, this will result in the clay dramatically increasing its ability to retain moisture by around fourfold.

This is a good option for those with a smaller area to fill, but mixing your whole garden to be 50% sand is unrealistic.

Adding sand in small amounts has no benefit to the soil

It would be wise to err on caution when applying sand. Despite much common misinformation stating that it is beneficial, it could further damage your garden soil and impact your garden’s efficiency.

Adding small amounts of sand should be avoided altogether. Doing this has no benefit and will likely exacerbate any pre-existing issues.

With high-quality compost, sand can be helpful when added. In this case, it should be used with frequent fertilizing because the nutrients and minerals may be lost due to leaching.

Comparisons of particles of clay and sand

Despite their small size, clay particles dominate in soil. Thanks to their size, more clay particles can fit into space, so their overall surface area is more significant than any other material within the soil.

Sand particles are much larger than clay, so fewer particles are required to fill the same space that clay would fill with many particles.

The result is that sand has a much smaller overall surface area and, compared to clay, has much less influence on the soil’s properties and characteristics.

Never add sand to prairie soil.

I can categorically say that adding sand to prairie soils is never a good idea. Adding small amounts of sand may seem harmless, but it can be worse than adding larger quantities to your soil. This is due to large sand particles mixing with the minute clay particles, resulting in a concrete mixture.

Remedies for dry clay soil

If your specific reason for adding sand to your garden soil is the soil is heavy and claylike, this section will focus on detailed ways to remedy this problem and prevent it from reoccurring.

We’ve established that sand isn’t an effective way to solve it, but some tried and tested processes will lighten the garden soil and make it better for growing.

Mix organic matter into your clay soil.

The best way to lighten clay soil is to mix it with much organic matter. If possible, you should create a layer of at least four inches consisting of compost, manure, leaf mold or mulch, wood chips, etc.

When the compost, manure mulch, and all those decompose, the resulting humus will create space within the clay particles and allow air.

Water will also move through the particles more efficiently, resulting in lighter garden soil consistency.

Topping up of organic matter in your clay soil is recommended regularly

This is an ongoing process, so you must regularly add organic matter. The case will decompose over time, so you need to keep topping it up.

The results from the first addition of organic matter will positively impact the garden soil. It will become lighter and easier to garden with every addition due to the nutrients from the mulch going into the soil.

Adding soil to soil

If you want a quicker alternative to using sand or organic matter to improve the quality of your garden soil, this might be the method for you.

Instead of wasting time and effort mixing organic matter into hard, heavy soil, you could take a more straightforward approach. Adding a substantial layer of good quality garden soil over the clay soil allows you to use this later for your gardening purposes.  

Benefits of clay soil

As much as I have criticized clay’s ability as a surface soil in this article, it makes a perfect bottom soil (subsoil).

Clay soil has good mineral and moisture-retaining capabilities; it holds onto those and then releases them to the plants above.

Using good-quality topsoil with clay soil as the base can be a highly effective growing environment to improve your garden.

Interestingly, this mixture is likely how your garden was before the house was constructed. When a home is developed, the topsoil is usually removed, leaving soil that is clay-heavy and difficult for plants to grow in. So by adding a layer of high-quality topsoil, you could say the garden is returning to its roots!

More effective alternatives to boosting your garden soil rather than using sand

Thankfully, you can employ other, more reliable methods to solve the issues with your garden soil. These techniques are more efficient than sand and pose less risk if they go wrong.

Let’s look at ways to improve garden soil’s poor draining and aeration properties without sand.

Using mulch is one way of boosting garden soil.

Using mulch prevents the soil from compacting and improves the overall aggregate structure.

Mulch is a handy tool for gardeners and is free! Its use results in less need for weeding, less watering, less frost damage, less compaction of soil, and overall improvement of plant health.

Plant-based, organic mulches will break down into healthy soils as time passes. Simply spreading five inches of organic mulch onto your garden soil will work wonders. Some excellent materials for your mulch mixture are; shredded bark, peat moss, leaves, grass clippings, compost, manure, and wood chips.

Keep your tilling to a minimum to better your garden soil

Avoid tilling your soil too much.

It is true that digging and tilling initially break up the clumps of soil and make the consistency more fluffy, but once the garden soil settles, it will become more compact and cement-like.

The only way to combat this is to add large amounts of organic matter every time you till the soil. Tilling when the soil is wet is hugely detrimental to its consistency and can damage the structure. If possible, gardening without tillage is the ideal scenario.

Look into using peat moss to boost your garden soil

Using peat moss is an effective way to break down garden soil. It works because it is very absorbent and holds water in the soil for longer durations than many other materials.

Be wary, though, if your garden soil is very claylike and thick; adding peat moss could worsen the problem.

FAQs on The Truth About Adding Sand To Your Garden Soil Pro and Cons

What are the different types of sand?
Essentially, sand comprises tiny grains of silica mixed with minerals such as clay and iron. Gravel, called grit sand, makes concrete and paving bases. Building sand, or bricklayer’s sand, is used for mortar for laying bricks, and silver sand is used to lock paving together.

Does grass grow through sand?
Sandy or heavy gravel soil may provide some benefits, such as good drainage, but it is unsuitable for growing grass. The moisture will move through the sand quicker than good quality soil, causing the nutrients to be washed away, depriving the grass of what it needs.

How do you make good topsoil?
For good topsoil to be healthy, it requires a wide variety of minerals. Iron, copper, zinc, sulfur, and chlorine are some of the most important. Create a base that is rich in those nutrients and add organic matter. Also, consider checking the soil’s pH and ensuring it stays in the 6 to 6.8 pH range.

Can I mix the builder’s sand with the soil?
Adding builder’s sand to your clay soil is not advisable because this type of sand is sharp, made of ground quartz, and the particles are relatively large. Adding this to your clay soil will make it cement-like, restricting air and water flow, and it will also end up hampering root growth.

Are you using dune sand for your soil?
Dune sand is commonly found in the desert and is white in appearance. They are good as rooting media for plants like succulents, seed sowing, and seed starting through root cuttings due to their sterility and neutrality, pH-wise. They are advantageous for horticultural practices.

Conclusion on should you add sand to your garden soil

Be sure to establish the needs of your garden soil before deciding on what approach to take, whether by adding sand or other materials. If the soil is claylike and clumpy, the remedy will differ significantly from if the soil is too moist or struggling to drain correctly.

We have discussed many alternative methods that provide the same benefits to your garden soil without posing a risk. My favorite is making an organic mulch layer on your garden soil; this is a great way to use leftover materials.

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