Although transplanting a new plant with friends is one of the many joys of gardening, I realized some plant owners and gardeners are usually unsure about their potting mix. In fact, many gardeners aren’t sure if it’s okay to put sand in the bottom of a planter.
You can put sand in the bottom of a planter, regardless of the planter’s size or the kind of plant you’re growing. Sand is an excellent potting medium to improve soil drainage, enhance soil aeration, and reduce complications due to overwatering.
However, you need to monitor the sand type, quality, and quantity to ensure it doesn’t hurt your plant in the long run. These are critical factors you must consider before you fill your planter because while plants don’t mind growing in some sand, different species have specific needs. In this article, I’ll explore all of these and then teach you how to fill your planter to ensure your potted plants thrive in any environment.
How Much Sand Should You Put in the Bottom of a Planter?
Every gardener and plant keeper knows that the secret to growing healthy and beautiful plants is to control every environmental factor involved in the process. So, if you’re putting sand in the bottom of your planters, you must ensure you aren’t using too little or too much. After all, you want to enjoy the aeration and drainage benefits of the medium without starving your plants of nutrients.
You should put enough sand to fill a quarter of the planter. This quantity is enough to improve the soil drainage, but it also ensures you can add generous amounts of nutrient-rich soil to the pot. However, you may need to experiment with different ratios to determine the optimal amount.
Remember to use horticultural sand to get the best results.
However, in some cases, you can also mix the sand into the soil or potting mix. Most gardeners use this technique when working with slow-draining soil, which can help improve overall soil drainage.
I recommend using a 50/50 ratio if you’re mixing the sand with potting soil, but you may need less sand if your soil is fast-draining.
How Sand Impacts Planter Drainage
Although this might come as a surprise, most plant keepers and gardeners don’t worry too much about the soil they use for their plants–especially when growing them in planters. After all, it’s relatively easy to control the environment of potted plants, and you can get sucked into keeping track of other essential metrics like temperature and humidity–neglecting your soil quality.
And while diligent gardeners focus on soil moisture content, aeration, and essential mineral levels, you must also consider precisely what kind of soil you use for your plants.
Of course, this part of gardening can be pretty challenging. Your soil provides support, aeration, water, and essential minerals to your plants. Therefore, it’s the reason your plant will thrive or die.
Understandably, most gardeners tend to outsource this part of gardening to plant retailers or opt for potting mixes to solve the problem. Although these are excellent practices and alternatives, you must understand why your soil is the way it is and learn how they benefit your plants.
Still, regardless of what type of soil you choose, it’s important to consider the big picture when keeping potted plants. So, while soil nutrients and root support are critical factors, you must also ensure your soil drainage is top-notch. I’ll discuss more about soil types in succeeding sections of this article.
Overwatering and underwatering can be catastrophic to your plant’s well-being, and the best way to ensure they thrive is to prioritize excellent watering and drainage practices. These include consistent watering times and a planter with drainage holes, but they also mean your soil needs to be suitable for your plant’s needs.
And that’s where sand can be an advantage.
In a nutshell, putting sand in the bottom of a plant growing medium is an excellent idea since it helps drain water efficiently and effectively. The high drainage property of sand is responsible for this process, particularly its coarseness and the size of the sand particles.
These features serve as significant advantages that help optimize your watering process.
Therefore, this sand layer in the planter’s bottom can serve as a quick-drain medium for the soil–regardless of what you’re growing or what kind of potting mix you use. It’s also a great technique to control the drainage rate, especially if you’re using hydrophilic soil like clay.
The coarse sand grains enable easy water filtration, and the significant air spaces facilitate quicker water penetration. It also keeps the ground from becoming wet and causing puddles–a serious problem if you’re keeping your planters indoors.
In the end, the added drainage of having a sand layer in your planter will help improve plant development.
Types of Sand for Gardening
As I’ve mentioned, it’s an excellent idea to include a sand layer at your planter’s bottom to help improve soil aeration and drainage. However, just not any sand will do if you want to keep healthy potted plants. So it’s necessary to examine the qualities of each sand to determine if they’re suitable for you and your plants.
Here are four main types of sand you can use for gardening:
- Builders’ sand
- Grit
- Horticultural sand
Let’s quickly explore what separates these sands from one another.
Builders’ Sand
This type of sand is probably the most familiar and comes to mind when most people think of sand. As its name suggests, its primarily used by masons and the construction industry for building materials. Therefore, some people also refer to builder’s sand as masonry sand.
However, regardless of what it’s called, all builder’s sand share the same properties. The sand has fine yet coarse grains that allow slow drainage. Therefore, they can hold water for longer and are excellent for plants that prefer moist soil.
Most gardeners typically use builder’s sand as parts of potting mixes instead of as layers since it doesn’t have the usual qualities for bottom soil. Still, you can use the sand if you don’t want to water often and if the plant doesn’t mind prolonged exposure to moisture.
And while builder’s sand shares some similarities with play sand, they’re not the same. So, I don’t recommend using play sand in your pots or gardens for whatever reason since it can be harmful to your plant’s health.
Grit
Grit–or sharp sand–is pretty similar to builder’s sand in many ways. However, its grains are larger, heavier, more coarse, and sharper than the latter–perfect for concrete mixes. Grit typically comes in the traditional brown color of most sand, but it has more drainage properties than builder’s sand.
So while it’s the optimum choice for professional landscapers and builders, you can use it in your garden to improve soil aeration and drainage. It’s usually paired with clay soil, but you can also add it as a layer to your planter’s bottom.
The sand is also referred to as river sand and builder’s grit in some circles since it’s the optimal choice for construction projects in wet areas.
Horticultural Sand
The best way to describe horticultural sand is as medium grain sand with medium-fine particles–specifically designed for plants and planters. It’s commonly known as potting sand and is used to optimize soil drainage and aeration.
Horticultural sand is the best type for planters and is pretty easy to recognize. The sand is as coarse as grit and consists of small and large particles of varying sizes. It’s usually crushed up sandstone or quartz, but granite works just as well.
In addition to its excellent drainage and aeration, horticultural sand also helps balance soil pH since it’s mostly inert particles. Therefore, you can use it as an ideal base soil for plant mixes.
And since the sand does not clump together when wet, it’s suitable for planters and plants in any climate.
You can also use horticultural sand as a mix instead of as a layer. In this situation, I recommend you combine it with poorly draining soil so that the result is perfect. You can also pair the sand with mulch to help control drainage even better.
In fact, horticultural sand is so helpful in gardening that most potting mixes contain it to some extent. Therefore, I recommend using this sand in your garden and at the bottom of your planter.
Final Thoughts
Sand is an excellent resource in gardening and plant keeping, and you can use it to improve soil drainage and aeration. However, you must use the correct soil type to get excellent results. Of course, it’s also vital to consider the amount of sand in the planter to ensure your plants thrive as much as you want.
