Key Takeaways
- Garden soil and potting soil are different and not interchangeable. Their composition varies and the use of each type of soil depends on the gardening project.
- Garden soil is a mix of native soil, minerals, and organic matter, and is designed to enhance the native soil’s composition in garden beds or raised beds.
- Garden soil provides nutrients thanks to its mix of minerals and organic matter, but it tends to have high water retention and can cause drainage issues, especially for container plants.
- The negative is that garden soil may contain pathogens, fungi, and bacteria, which may be harmful in a contained environment.
- Potting soil, by contrast, is designed for optimal moisture retention and good drainage. Its composition promotes aeration and is designed to be lightweight to allow for healthy root growth.
- Potting soil is usually sterile and has no harmful pathogens, making it ideal for indoor plants and seedlings.
- For outdoor gardening and raised beds, garden soil is the ideal choice. For container gardening and potted plants, potting soil should be used.
- Starting seeds and seedlings requires a specific mix that is light, sterile, and promotes ample root growth, making a specialized potting mix a good choice.
- Adding soil amendments and additives to garden soil and potting soil can enhance the quality, soil structure, and drainage of the soil. Examples of soil amendments and additives are compost, perlite, vermiculite, bark, coir, sphagnum moss, lime, bone meal, and manure.
- Alternative and innovative soil blends have emerged, incorporating unique materials such as coconut coir or slow-release fertilizers.
- Specialized soil mixes catering to specific plants are widely available, such as well-draining, sandy soil for cacti and succulents, ericaceous compost for acid-loving plants, and soil mix with mushroom compost for vegetables.
Table of Contents
Understanding the difference between garden soil and potting soil is an important key to any successful garden.
Garden soil is native soil and contains organic matter, minerals, and nutrients to enrich the composition. Conversely, potting soil is a blend of soil along with soil amendments such as perlite, peat moss, and compost, among others, that increase drainage, aeration, and moisture retention characteristics.
When choosing either garden soil or potting soil, consider the plant’s needs and location.
With a little forethought and some knowledge of these soils, your garden will be healthier and produce thriving plants.
Read on to find out the differences and similarities between potting soil and garden soil.
What is Gardening Soil?
Garden soil is a mixture of native soil, minerals, and organic matter, which may include clay, silt, and sand. The composition of garden soil heavily depends on the local environment and climate.
Garden soil is usually found under the top six to eight inches of topsoil, which contains mineral and organic matter that provides essential nutrients for plant growth.
To accurately assess the content of garden soil, a soil test can be performed, which will provide specific information regarding nutrient content and any soil amendments that may be required.
- Garden soil may include:
- Clay: fine-textured particles that help retain moisture and nutrients
- Silt: medium-sized particles that give the soil structure and support plant roots
- Sand: large particles that improve soil drainage and aeration
- Organic matter: Technically called humus, it is decomposed plant and animal material that enriches soil fertility.
What is Potting Soil?
Potting soil, also called potting mix, is specifically formulated for use in container gardening and does not actually include soil. It’s designed to provide optimal growing conditions for plants in pots and other containers.
Potting soil is a blend of various materials that promote aeration, drainage, and moisture retention.
Common soil amendments that are found in pre-mixed potting soil include:
- Peat: decomposed organic matter that retains moisture and nutrients
- Compost: decomposed organic material that adds nutrients and fertilization
- Perlite: lightweight volcanic rock that aids in aeration and drainage
- Vermiculite: mica mineral that improves water retention and nutrient availability
- Sphagnum moss: organic material that helps retain water and air
- Bark: a byproduct from the lumber industry that adds structure and drainage
- Coir: also known as coconut coir, it’s the fiber from coconut and it promotes moisture retention and aeration
In summary, garden soil is primarily used for in-ground gardening, while potting soil is best suited for container plants. The compositions of these soils differ in order to provide the specific growing conditions needed for their intended purposes.
Key Differences Between Garden Soil and Potting Soil
| Characteristic | Garden Soil | Potting Soil |
|---|---|---|
| Texture | Can be a bit powdery | Rough or coarse |
| Color | Ranges from light to dark brown | Typically dark in color |
| Ingredients | Pure topsoil, humus | Sand, perlite, peat moss, vermiculite, pebbles |
| Water Capacity | Can hold water for a long time | Doesn’t stay moist for a long time |
| Fertilizer Ready | Yes | Yes |
| PH Level | Adjustable | Adjustable |
Nutrition and Fertility
Garden soil contains both mineral and organic matter, providing nutrients for plants. This topsoil is formed through natural processes in the environment and contains a mix of materials necessary for plant growth. In contrast, potting soil is a mixture of materials specifically formulated to meet the needs of potted plants. It often includes added fertilizers and amendments to provide the necessary nutrients for the plants.
Moisture and Drainage
Garden soil tends to have a greater water retention capacity due to the presence of clay particles and organic matter. However, its high water retention can cause drainage issues, leading to root rot in container plants. On the other hand, potting soil is designed with optimal moisture retention and drainage in mind. The inclusion of materials such as perlite and vermiculite ensures that excess water can quickly drain away, reducing the risk of root rot in potted plants.
Aeration and Porosity
A well-aerated and porous soil is crucial for healthy root growth. Garden soil tends to be denser and can sometimes compact too easily, restricting root growth and hampering the intake of oxygen and nutrients. Potting soil is designed to be more aerated and porous, including materials such as peat moss, coir, and perlite to maintain proper air and water exchange for plant roots.
Weight and Texture
Garden soil is heavier and denser due to its natural components, such as clay, silt, and sand. This weight and density can cause issues with container plants, as they can limit root expansion and contribute to poor drainage. Potting soil is lighter and less dense, which helps ensure proper root growth and oxygen exchange in the container environment.
Sterility and Pathogens
One of the most significant differences between garden soil and potting soil is the presence of pathogens, fungi, and bacteria in garden soil. These naturally occurring microorganisms can be harmful to plants when they are introduced into a contained environment.
Potting soil, on the other hand, is often sterile and devoid of any harmful pathogens that could cause diseases in container plants. This is especially important for indoor plants and seedlings, which may be more susceptible to diseases if exposed to these pathogens.
Choosing the Right Soil for Different Uses
Outdoor Gardening and Raised Beds
When it comes to outdoor gardening and raised beds, garden soil is the ideal choice. This type of soil is a blend of topsoil and nutrient-dense components, such as composted bark or mushrooms.
Garden soil is rich in organic matter, making it great for supporting the growth of various outdoor plants, including shrubs, trees, and other greenery. Due to its heavier texture, it holds water longer than potting mixes, providing a balanced environment for outdoor plants to thrive.
Remember that the quality and characteristics of garden soil may vary, so choose one specific to your plant’s needs.
Container Gardening and Potted Plants
Opt for potting soil when dealing with container gardening and potted plants. This sterile soilless mix is a blend of peat moss, compost, and perlite, with possible additions of aged pine bark, vermiculite, or moss.
Potting soil offers better drainage and aeration for plants that grow in containers, preventing root rot and overwatering. It is especially suitable for indoor plants, succulents, cacti, and African violets, as it promotes healthy growth and reduces the risk of diseases.
For the potting soil we use, check out
Starting Seeds and Seedlings
Starting seeds and seedlings requires a mix that is light, sterile, and encourages ample root growth. In these delicate stages, it is best to utilize a specific seed-starting mix or a potting mix with added components for better germination and growth.
Avoid using dense garden soil for seedlings, as it can hold too much water and cause problems with root development. Instead, look for mixes designed for seedlings or customize your potting mix to ensure optimal growth conditions for your newly sprouted plants.
How to Make Your Own Soil Mix
Ideally, if you’ll be making your own potting mix with the use of commercial topsoil, you just really need to mix it with compost or peat moss.
If you do make your own potting soil, you can control the pH level to your liking. If you are handy, you can even test your soil for pH levels.
However, if you’ll start from scratch, here are the ingredients you should get to create your own potting mix.
Steps for Making Your DIY Potting Soil
Once you have gathered the materials you need, here are the steps you can follow to create a homemade potting mix for your plants.
Gather Sterilized Potting Soil
Get one gallon of sterilized soil (or topsoil) and put it in a big container. You can use a big bowl or a basket for this.
Add Soil Additives to the Potting soil
Add a gallon of peat moss or sphagnum peat moss that’s coarse and another gallon of sand, perlite, or vermiculite which has a rough texture that allows good drainage. However, this can still give you a good enough time to let your soil stay moist.
Mix Potting Soil and Soil Additives
You’ll have to use bare hands while mixing the ingredients so that you can get a feel of how coarse and loose your mixture is.
It’s important that your mix feels rough or gritty so that it can promote good drainage when you finally use it for your plants.
Adjust the Amount of Soil Additives
Adjust the amount of soil, perlite, sand, peat moss, or vermiculite as needed. You can keep doing this until you have your desired texture.
FAQ
What are the main differences between garden soil and potting soil?
Garden soil is an amendment that is mixed with native soil and used for in-ground planting. It typically contains organic materials, minerals, and other nutrients. On the other hand, potting soil is a sterile medium designed for use in containers, such as potted houseplants and window boxes. It is usually composed of materials like bark, sphagnum moss, perlite, vermiculite, compost, and coconut coir.
What are the benefits of using potting soil over garden soil?
Potting soil offers numerous benefits over garden soil for container gardening: it is sterile, inhibiting the growth of pathogens and pests; it has a lighter and looser texture that promotes root growth, proper aeration, and drainage; and it is tailor-made to be rich in nutrients, ensuring consistent plant support.
Can garden soil be used in containers?
It is not recommended to use garden soil in containers because it can become compacted, leading to poor drainage and oxygen flow. Also, garden soil may carry pathogens and pests. Instead, use quality potting soil specifically designed for container gardening that provides proper drainage and aeration and is free from pests and diseases.
How do I convert garden soil into potting soil?
To convert garden soil into potting soil, you’ll need to mix it with additional components, such as perlite or vermiculite, to improve drainage and prevent compaction. Additionally, blend in organic matter like compost, aged manure, or coconut coir to provide essential nutrients. However, fully sterilizing garden soil can be challenging, so starting with a premade potting mix may be a better option for container plants.
Is it possible to mix garden soil and potting soil?
Yes, it is possible to mix garden soil with potting soil. This combination can be used for planting in raised beds or when you need to amend the native soil to provide better nutrition and drainage. Still, for container gardening, it is generally better to stick with quality potting soil.
References
Lindsey Hyland grew up in Arizona where she studied at the University of Arizona’s Controlled Environment Agriculture Center. She continued her gardening education by working on organic farms in both rural and urban settings. She started UrbanOrganicYield.com to share gardening tips and tactics. She’s happy to talk about succulents and houseplants or vegetables and herbs – or just about anything in a backyard garden or hydroponics garden.