We know that many plants are capable of growing in pure sand.
Desert flora, including cacti and succulents, wouldn’t exist without the ability to adapt to sandy conditions!
However, that isn’t the case for most plant life on Earth. So why would you ever add sand to your garden in the first place?
Actually, sand is a key component of healthy soil. Sand helps balance out the organic matter that makes up fertile soil while also improving drainage and preventing waterlogging.
Is all sand created equal? No!
For example, the sand you buy from your local hardware store is likely not the same as the sand covering your favorite beach.
River sand is just one type of sand you can safely add to your garden soil. With that said, it’s rarely the best option available.
How Is River Sand Different From Other Types of Sand?
Technically speaking, all sand is made up of the same basic materials.
Sand, whether naturally occurring or mined from a quarry, consists of extremely fine particles of rock and minerals.
In geology, sand is most often categorized by the types of rocks and minerals particles present.
But in landscaping and construction, the size and shape of these particles are what matter most.
You may be familiar with several other types of sand, including:
- All-purpose sand — Coarse sand used in many landscaping and construction projects
- Play sand — Soft, processed sand used to fill children’s sandboxes and playground areas
- Masonry sand — Fine sand used for mixing concrete or grout
As the name implies, river sand comes from river banks. This sand is made up of whatever rocks and minerals are common to the surrounding area.
One of river sand’s defining traits is its smooth, rounded granules. This quality is a result of the river water eroding the sand particles over time.
How Does Sand Affect Plant Growth?
Sand is incapable of holding onto essential nutrients and moisture the way other types of soil are. This limits the resources available to the plant’s roots.
While plant species that are specially adapted to sandy soil — cacti, succulents, etc. — can survive these conditions, most species cannot.
But that doesn’t mean any amount of sand is harmful to the average plant.
In the right quantities, sand can actually improve soil drainage and prevent compaction. The challenge is finding an ideal balance for your own garden’s needs.
Can I Use River Sand for Gardening?
Yes. With that said, river sand isn’t the preferred medium for supplementing garden or potting soil. Coarse sand is recommended.
Also, you should not use river sand collected from a natural source in your garden.
Since naturally occurring sand is made up of materials found in the surrounding area, you have no way of knowing the mineral content of the resulting sand.
In some cases, natural river sand contains minerals that can damage the soil and your plants.
Do I Have to Treat River Sand Before Using It in My Garden?
No, but you may want to rinse it.
The sand sold at your local garden center or home improvement store will almost always be processed.
This removes non-sand particles and other contaminants before the sand is bagged for sale.
Even heavily processed river sand may still contain dust. Fine rock dust can interfere with soil drainage, counteracting the whole point of adding sand to your garden in the first place.
The best way to rinse river sand is by placing it in a large bucket or trough. Add water and use a garden hose or other tool to agitate the sand.
Drain the container (preserving the sand at the bottom) and repeat until the water remains clear.
Can I Use All-Purpose Sand for Plants?
Adding small amounts of river sand to your garden won’t cause significant harm.
But if you want to enjoy all of the benefits of supplementing your garden with sand, coarse all-purpose sand is the best option.
Unlike river sand’s smooth particles, all-purpose sand particles feature jagged edges. This seemingly small detail is the key to well-draining soil !
The rough edges of all-purpose sand create small pockets within the soil that allow oxygen and water molecules to collect. They also support the surrounding soil to prevent compaction.
For the best results, select an all-purpose sand labeled for horticultural use. These products are made specifically for use as soil amendments.
Should I Mix River Sand With Soil?
Sand is a popular soil amendment for both garden beds and containers.
But just because you can mix river sand into the soil doesn’t always mean you should.
Sand is used to break up and reduce the weight of compacted soil. It also improves poor drainage (one of the most common symptoms of soil compaction).
If your garden soil contains large amounts of clay, using sand in conjunction with organic fertilizer can drastically improve the soil quality.
Yet blindly adding sand to already balanced soil will do far more harm than good.
Some gardeners also oppose the use of sand as a soil amendment because it can actually make the problem worse.
Particularly heavy soil can require a 50-50 ratio of sand to soil. Mixing in any less than this will just add to the soil’s weight without improving drainage.
Can I Mix Sand With Compost?
Yes. Adding sand to compost is a great way to add bulk while also improving aeration and drainage.
Some gardeners opt to add sand directly to their active compost piles. Others mix the sand and compost immediately before adding it to their gardens.
When mixed, sand and compost closely resemble traditional potting soil. Start with a 50/50 blend.
You can always adjust the mixture as needed depending on how your plants respond.
7 Alternatives to River Sand for Gardening
1. Horticultural Sand
Horticultural sand is the go-to medium for supplementing compacted soil.
This material can be used in the garden or for potted plants. Horticultural sand features large, coarse granules.
It’s also important to note that horticultural sand is chosen specifically for its mineral content (other sand may contain minerals that will damage garden soil or plant roots).
To the uninitiated, perlite looks and feels a lot like puffed rice. And this description isn’t far off, since perlite is produced by heated and “popping” pieces of volcanic glass.
Perlite is very lightweight and porous. As a soil amendment, perlite improves drainage and aeration. It’s also extremely effective against compaction.
Perlite is extremely popular for potted plants, where it can be easily mixed throughout the soil.
To use perlite in the garden, spread the granules over the soil’s surface (you may want to incorporate them into the top layer of soil to keep the perlite from blowing or washing away).
The perlite will slowly work down into the garden soil and improve drainage and aeration.
It’s easy to think of compost as a dense, heavy material.
But, when added to soil low in organic matter, compost is actually a great option for improving drainage and aeration.
While compost encourages proper drainage, it also retains moisture. This results in an extremely balanced soil composition that resists drought as well as oversaturation.
4. Peat Moss
Peat moss is not a species of moss. Instead, it’s a byproduct of plants and other organic materials breaking down in bogs of thousands of years.
Adding peat moss to garden soil results in a mixture that is lighter and softer.
Peat moss also improves aeration and drainage. Like compost, peat moss is great at retaining moisture without weighing down the soil as a whole.
Vermiculite is made of silica flakes that expand when exposed to water. This material holds onto important nutrients like potassium, calcium, and magnesium within the soil.
Although vermiculite looks and feels much like river sand, it is actually highly absorptive.
This allows the vermiculite to hold onto moisture when needed much like organic soil amendments like compost or peat moss.
However, vermiculite is not the best choice for soil that needs to drain extremely well. It also doesn’t aid in aeration nearly as much as other common amendments.
Mulch will not improve your garden soil’s drainage and aeration overnight.
But over time many types of mulch will break down into the soil and increase the amount of organic matter distributed throughout.
More organic matter results in soil that is overall lighter, better aerated, and less likely to become over-watered.
7. Coconut Coir
Coconut coir is a fibrous material harvested from the outer husk of a coconut.
You can use coconut coir to supplement heavy clay soils and areas with too much sand.
Like many river sand alternatives, coconut coir simultaneously improves soil drainage and water retention.
Using this material in your garden also means repurposing waste from the coconut industry that would otherwise go in the trash.
Sand is an important part of any gardener’s arsenal, especially if you live somewhere with particularly heavy, clay-filled soil.
River sand can be used to boost your garden soil’s drainage in a pinch. But river sand is sometimes too fine and dusty for effective drainage.
You should also never source river sand from nature. Not only could harvesting “wild” river sand harm the ecosystem but you never know what kind of minerals and chemicals could be hidden within (and all of those compounds will just end up in your garden soil).
Instead, we recommend opting for a more effective alternative like coarse all-purpose sand, horticultural sand, organic compost, or perlite.
These materials offer many of the same benefits as river sand without the potential drawbacks.