Potting Soil
What is the Difference Between Garden Soil and Potting Soil?
Potting soils, on the other hand, are specifically designed for container gardening. It’s usually made of ingredients like peat moss, coconut coir fiber, perlite, pumice, vermiculite, compost, and/or aged bark. Potting soil is light and airy which helps with drainage and air circulation. It’s perfect for houseplants, container gardens, and starting seeds because it provides a balanced environment with consistent moisture and nutrients. Unlike garden soil, soil for potting containers doesn’t easily compact, which makes it ideal for pots and planters.
Why Potting Soil Matters
Optimal Drainage and Aeration:
Soil for container plants is designed to drain well in order to help prevent water from sitting around which can cause the dreaded root rot – a condition where plant roots start to decay due to excessive moisture levels blocking oxygen flow to the roots. Including materials like perlite, high-fired baked clays, and coir fiber helps keep the soil light and airy, allowing roots to breathe.
Nutrient-Rich Composition:
The nutrient-rich composition of an indoor potting mix is important because it provides essential nutrients that plants need to grow and thrive. These nutrients include “the big three” – nitrogen, phosphorus, and potassium. Micronutrients refer to trace minerals like calcium, magnesium, and iron, and can also be incorporated. A good nutrient combo supports healthy root development, vigorous growth and abundant flowering or fruiting - depending on which green friends you are growing. All of this can lead to stronger, healthier plants with better resistance to diseases and pests.
Perfect pH Balance:
The pH balance of soils affects how well plants absorb those nutrients we just talked about. Most plants do best in soil that's slightly acidic to neutral, with a pH between 6.2 and 6.8. If the pH balance is too low or too high some nutrients can become less available to the plants – leading to deficiencies and poor growth.
*Click the image above to learn more about ideal soil for plant growth.
Common Issues with Generic Potting Mixes
Many commercial potting mixes are often not designed for indoor conditions for several reasons:
- They are formulated to retain a high level of moisture to cater to a broad range of gardening needs.
- They often compact easily which reduces the amount of oxygen flow reaching the plant roots.
- Generic formulas are meant to be versatile and cost-effective for a wide range of plants/conditions. However, they fail to meet the specific needs of plants that require particular ratios of moisture, aeration and nutrients.
- The quality of materials used in mass-produced soils often miss the mark – especially when it comes to providing the necessary structure indoor plants require. Additionally, these mixes can sometimes contain filler ingredients that do not contribute to the health of the plant and attract pests.
If you opt for a mix that is specifically formulated to address these issues, you will be able to provide your green friends better aeration and drainage. As a result, your indoor plants will experience a less stressful environment which ultimately promotes healthier and more resilient growth. As an added bonus, a custom mix will give you more leeway in your watering and care routine. This makes it easier to maintain your plants even if you occasionally make mistakes – which we all do!
Choosing the Right Soil
Selecting the perfect soil for your container friends depends on the specific needs of your plants. Here’s what we suggest you look for:
Read the Ingredients
- Opt for a mix containing organic matter like coconut coir, bark or wood chips for moisture retention. These ingredients help keep the soil moist without becoming waterlogged.
- Look for perlite or pumice, which can help improve drainage and aeration. These materials assist in preventing the soil from compacting and making sure that the roots get enough air longer term.
- Choose potting soils that use sustainable and eco-friendly materials, like coconut coir instead of peat moss. Making this choice helps support environmentally conscious gardening practices. Peat moss is also a super cheap material, which is why it's used so often. It does work well in the ground or in optimal conditions like a greenhous. Unfortunately, peat moss is a poor performing component indoors. It get's chalky and dense and hydrophobic (repels water) relatively quickly indoors. It also doesn't dry very consistently, so you get a mix that might be in a spot that dries all the way through in a few days, or that same spot later in the year might not ever dry out appropriately between normal waterings. This puts a ton of stress on your plants as well as your own mental well being as the caretaker.
Tailored Mixes
- Some plants (succulents and cacti) require an extra well-draining mix to mimic their natural habitats. We highly suggest finding a potting mix that is specifically designed for these plants. These special soils generally contain less organic material (previously living components) and more grit to reduce the amount of moisture retained at any given time for these desert dwellers.
- For other plants – such as orchids, there are specialty mixes available that cater to their unique growing conditions. Orchids are epiphytes, meaning they naturally grow on trees and get consistent air flow to their roots rather than sitting in soil. Opt for a lightweight, chunky mix that provides excellent drainage.
Nutrient Content
- Don't be fooled by big box potting mix marketing. Living soils and soils with fertilizers added are great, but you're not good to forego adding nutrients and beneficial microorganisms with any of those mixes for the long term. You typically have enough nutrients to feed the plant for up to 3 months, but you'll need to get comfortable with your own fertilizer regimen.
- Find a good organic fertilizer that you can add regularly without burning your plants. A mix of immediate and slower release nutrients is usually best. Worm castings are also a great periodic addition to your normal feeding regimen.
- Adding beneficial microbes like mycorrhizae (fungi) and bacillus (plant protecting bacteria) go a long way toward protecting the long-term health of all your plants.
DIY Potting Mixes
Creating your own indoor potting mixes can be a really fun way to make sure your plants get exactly what they need. Sol Soils has a number of different amendments, like pumice, super chunky (large) perlite, and LECA balls that you can mix and match. This lets you create custom blends that are perfect for aroids, succulents, orchids, cacti, bonsai trees – you name it! It's all about experimenting to find the right balance for drainage, aeration, and nutrients. Here are some ideas to help you get started with your own unique potting mixes using soil amendments..
- Pumice
- Calcined Clay
- Granite Chips
- Lava Rock (<1/2" is ideal here, so ignore the big bags of landscape lava rock from big box stores for a potting mix component)
- Chunky Perlite
- Pine Bark
- Orchid Bark
- Coconut Chips
- Coconut Coir
- Chunky Perlite
- Pine Bark
- Compost
- Coconut Chips
FAQs
How do you store potting mix?
To store your soil properly you’ll want to keep it in a dry place away from too much humidity to avoid mold growth or pets getting into the mix. Place the soil in a cool, dark location, that is away from direct sunlight, and off the ground using shelves or pallets. Label containers with the type of soil and date, and make sure they are sealed to prevent pests. Periodically check the soil for any signs of issues to keep it fresh and ready for use. If you do see mold on any potting mix, it's still just fine to use. You can discard the portions with obvious growth, but keep in mind a high quality soil should be active with microbes and mold is simply a sign of organic material breaking down by these microbes.
Can you reuse soil?
Yes, you can reuse potting soils. However, you’ll want to make sure it didn't have some sort of pathogen that caused the previous plant tenant to perish. If you're not sure, dispose of the soil. When refreshing Sol Soils potting mixes the majority of the materials don't break down over time, so what you'll want to add back is organic material which has broken down and or been consumed by the plant over time. Adding coconut husks, coconut coir, composted pine bark, worm castings, or other container-use composts back to the mix works well. Just don't add more than about 50% of this new material unless you want it to perform differently than our normal fresh mixes.
Also note that Sol Soils Performance Mixes allow you to go longer between repotting of the same plant unless it just needs a larger pot. The mixes are typically good for 2-3 years before needing some refreshment vs. traditional potting mixes when need a refresh every year or so. Higher quality materials have these benefits. :)
Let's Wrap This Up and Get Planting!
Potting soil is the cornerstone of any successful container gardening journey. By understanding its components and benefits, you can provide your plants with the best possible environment to flourish. So, whether you go with a commercial mix or you create your own, you are giving your plants a great chance at having a vibrant, healthy life.
Explore all of our premium soil options at Sol Soils to give your plants the start they deserve and Grow Happy Plants!