You can notice the difference between potting mix and potting soil in the terms themselves. You have probably noticed that these terms are often used interchangeably because both refer to gardening. Potting soil hints that it’s a soil medium, other materials are also added, but the main element is dirt. Potting mix, in its turn, is sort of a ‘mix’ of different matters and completely soilless. Secondly, they provide different environments for the plants, so they are used for other purposes. Potting soil can be used in the garden and for plants in containers. Potting mix is for the plants in the pots since it will be too pricey to fill the garden with potting mix (we will talk about prices later). So long story short, the answer to the question ‘is potting mix the same as potting soil’ is no.
What is Potting Soil?
Potting soil is a collective term for mediums such as garden soil, potting soils, etc. Houseplants need to be grown in specific soil so that ordinary garden is not suitable. The difference between potting soil and garden soil is very clear. Garden soil is used for outdoor plants and potting soil for the ones growing in containers. Garden soil is too dense to let the water drain fast enough; it will be useless for potted plants. Potting soil lacks needed nutrients for outdoor plants.
When we talk about potting soil vs. potting mix, we also should keep in mind that potting soils aren’t sterile. We don’t want to scare you, but there’s a possibility you can find gnats and other types of flies as rather an unpleasant surprise in your potting soil. This is not an immense tragedy because neem oil will quickly solve this problem. Secondly, mixes and soils have different ingredients. Potting soil often contains dirt, sand, minerals, and other organic matter. That’s why it is heavier compared to the lightweight potting mix: the last one is entirely soilless and contains ingredients that don’t weigh much, such as peat moss, perlite, coir, vermiculite, and sphagnum moss.
Since pots are fully restrained spaces, it’s harder for a plant to meet all its needs. So when we need to create conditions similar to the natural ones, the soil will hold the required amount of water and provide enough space for air and roots. And plants in containers will have problems with that because pots are shallow. That’s why potting soils come in handy since they can meet the needs of plants in containers. The ideal potted plant soil consists of mineral elements like sand, clay, and silt (45%), compost (5%), air (25%), and water (25%). So thanks to potting soils, plants can get everything they need.
What is the Potting Mix?
As mentioned, potting mix is the soilless potting medium created mainly for indoor plants to make their growing process faster. Maximizing the plants’ growth is possible because the potting mix has the correct elements. Usually, the potting mix consists of vermiculite, perlite, peat moss, pine bark, etc. These elements are more prominent than soil particles but aren’t blocking the roots. It’s quite the opposite due to their light weight; they make it even easier for the roots and provide better aeration. Also, such elements as peat moss enable good water retention. These characteristics make potting mix the most optional potting medium for planting seeds. Additionally, potting mixes can be created explicitly for Cactus or Orchids, developing environments similar to their native ones.
Potting Mix vs. Potting Soil — Main Differences to Know About
Soil for potted plants and potting mix are not the same. Just pay attention to the weight of the substance. The difference is caused by the fact that potting soils can contain (or not) dirt, but potting mixes don’t include soil. Another difference, already mentioned above: potting soil is not sterile, so there’s a risk of pathogens that can cause various diseases. There’s no confrontation like potting mix vs. potting soil. They are used for slightly different purposes. For example, potting soil will be way more helpful for outdoor pots. Meanwhile, potting mix is considered better for container gardening because of its sterility, better drainage, and aeration. Here are the main differences:
- Weight. Since the potting mix is soilless, it’s lightweight compared to the potting soil.
- The main ingredients. The ingredients of potting soil are garden soil, minerals, sand, and organic matter. The main potting mix ingredients are the bark, coir, sphagnum, perlite, and peat – the most significant and common elements. This material is beneficial due to its ability to absorb moisture. So that’s the reason why sometimes these substrates are called soilless potting mix or soilless medium.
- Shelf life. The potting soil is long-lasting because it is natural, and potting mix expires faster. So, it would be best to keep in mind that some ingredients in peat moss can decompose and be aware that it’s not safe to use when its term expires. Opened bag of potting mix should be used in two months, and an unopened one can last for a year or even two.
- Price. The potting soil is cheaper than the potting mix. Since the latter consists of elements that are not as common as dirt or sand, that’s the reason why you can find potting soil almost anywhere. You can even use the one from your garden. On the other hand, the needed potting mix is slightly harder to find. Since different plants have different needs, they require additional ingredients. Hence there are unique potting mixes for Cacti, Orchids, or Succulents. So before choosing the potting mix, check its components.
- Purpose. Potting mixes are made for container gardening and are perfect for seed starting because they were created for this. You can use potting soil for this purpose, but it will be less successful.
- Nutrient-richness. Potting soils are mostly fully organic, so pay attention to this if you want an eco-friendly option. Potting mixes, as the name hints, is a kind of mix of different components that are not always fully organic but at the same time have all the needed elements for the plants.
Potting Soil Pros & Cons
Pros of Potting Soil.
- Cheap. Potting soil can be found in any gardening shop and is incredibly affordable.
- It lasts longer. You don’t have to worry that it will break fast.
- Nutrient-rich. The dirt is rich in minerals and organic matter compared to more sterile potting mixes. So it will supply the plant's nutrient needs.
- An eco-friendly option. It’s mostly fully organic. If you care about the environment, then check this one.
- Reusable. However, using it for the second time increases the risk of diseases. But you can prevent it by drying used potting soil in the sun and adding organic matter like coconut coir and fresh peat moss. In any case, don’t reuse the soil which previously has grown the diseased plant.
Cons of Potting Soil.
- Worse aeration compared to the potting mixes. Their texture and weight allow less air movement, which is why they can get easily compacted.
- Water drains slower. This quality makes it not the best choice for potted plants since they can get wet roots, harming your house plants.
- Not perfect for seed starting. Mentioned drawbacks don’t make it an ideal potting medium for planting seeds. Also, in this case, potting soil’s weight won’t help grow the freshly planted seeds.
Pros & Cons of Potting Mix
Pros of Potting Mix.
- Texture. The fluffiness of the potting mixes is a characteristic of a suitable potting medium. Since it allows free air movement and provides roots with space, they can propagate easier.
- Good aeration. Potting soils can easily compact, but it is not about potting mixes! Potting mixes provide the plants with excellent drainage.
- It holds water better. Peat moss, perlite, and vermiculite (the most common components of the potting mixes) are praised for balanced water retention, which is almost perfect for many plants.
- Better drainage. Good drainage is also provided with aeration because of a good combination of the components.
- You can find a needed combination of nutrients for your plants. Since this potting medium was created explicitly for plants in containers, they mimic their natural habitats and provide them with needed nutrients.
Cons of Potting Mix.
- Price. Since it’s designed for the specific needs of plants, it can be pricey. But the price tag is justified because you won’t second guess it, and the plant will receive everything it needs.
- Won’t last for long. Potting soils stay for more extended periods than potting mixes. The latter will break down eventually, so pay attention to the expiration date.
- Lightweight. Its weight is helpful with aeration. Unfortunately, it can also be a drawback because it can be blown off in the wind in windy locations. In such a case, you can buy a heavier container.
How to Choose the Right One Between Potting Mix and Soil
- Read the labels to learn ingredients and how to use potting mix or potting soil. You can choose if this potting medium suits your plant. If the product doesn’t have a potting soil ingredient list, it automatically doesn’t worth your attention.
- Different plants = different needs. Focus on the plant’s needs because plants like Aloe Vera like plant soil and potting mixes with good drainage to prevent root rot. Carnivorous plants are fond of wet soil, and potting mixes with sphagnum moss will be helpful. Most ferns thrive in moist and slightly acidic soils. Bromeliads need well-draining potting soil that can hold moisture. This list can be almost endless, but long story short — keep your plant’s needs in mind, and you will find the right mix or soil.
- Potting mixes and soil serve different purposes. For large-scale gardening, potting soil is the best. Potting mixes, in their turn, were created for container gardening.
- If you tend to be away often and don’t have an opportunity to water plants when needed, choose potting mix soil with good water retention.
Potting Soil and Potting Mixes Types
So here’s the list of different types of potting soil for indoor plants and potting mixes to help you choose the best for your plant.
- All-purpose potting soil. It’s a universal potting medium containing soil, compost, bark, perlite, sand, and rarely vermiculite. This soil will work for indoor and outdoor plants due to its fertility and ability to hold moisture.
- Mix for Cactuses and Succulents. All-purpose soil won’t work with them because that type of soil retains too much water, which is not suitable for these plants. So they need a little more drainage, which this mix can provide since it consists of an equal part of potting soil, coarse sand (or gravel), and perlite (or pumice).
- Premium mix. This mix consists of organic composted materials, natural rock trace elements, lime, slow-release fertilizers, zeolite, coir fiber, iron, etc. The premium mix benefits the plant because it gives it a lot of nutrients, stimulates roots, and saves water, which means you can water the plant less.
- Orchid potting mix. The look of this mix is quite unusual compared to other potting soils and mixes. Orchids are Epiphytes and need soil only as a pillar because they get nutrients and moisture from the air. In their natural environment, they grow on tree bark. Because of it, they need a lot of bark in their potting mix. Very often, mixes for Orchids contain perlite and charcoal because they help with drainage.
- Seed starting soil. It is a unique mix for such an occasion when you want to grow something new out of seeds. Seedlings aren’t the same as regular plants, so they have different soil needs. The best seed starting soil consists of sphagnum peat moss, vermiculite, and sphagnum peat moss.
Can You Mix Potting Soil with Garden Soil?
Such a mix won’t be great for potted plants, but outdoors it will be ok, so you can combine them for raised beds.
Can You Mix Potting Soil with a Potting Mix?
You can buy such mixes. They are mostly labeled as ‘For raised beds,’ but you can do it yourself again. Just combine potting soil or garden soil with potting mix.
Can You Use Outdoor Potting Soil for Indoor Plants?
Since the outdoor potting soil is heavier, has worse water retention, and doesn’t allow needed airflow for indoor houseplants, it’s not a bad idea to use potting soil in this case.
What’s the Difference Between Indoor and Outdoor Potting Soil?
They serve different purposes, outdoor potting soil is good for the garden, and potting soil is suitable for outdoor container gardening.
Choosing suitable soil is the key to success because it will help your plants to flourish. We hope this information was helpful and you will find the appropriate potting soil mix.