Is potting soil real soil?
No, it is not. Potting soil is an alternative to the actual soil to grow indoor plants. It is lightweight and retains moisture well. Patio containers or hanging baskets can easily bear the weight of potting soil. Apart from growing plants, potting mix is used for seeds and to grow root cuttings.
Making potting soil for indoor plants from scratch is budget-friendly and easy. You will find several DIY recipes on the internet, but the ones mentioned here are tested and tried.
Try these custom potting mixes instead of using the same potting mix for all your container gardening needs.
Which Potting Soil for What Plant?
You can prepare different potting soil blends at home, similar to commercial potting soils. However, according to your planting needs, they can differ in nutritional content, texture, water-retaining capacity, and density.
The basic potting soil recipe comprises peat moss or coco coir, vermiculite, and perlite. Most urban gardeners use it as an all-purpose potting mix for their houseplants.
Combining the ingredients in proper ratios helps you cater to the various gardening uses.
For example, root cuttings and seed starters should be fine-textured mix and light. Pine bark or coarse sand mixture is required in high percentage for shrubs and trees.
Succulent and cactus plants love the gravel texture or sandy potting soil. An all-purpose potting mix is suitable for growing various plants such as vegetables, annuals, perennials, and tropical plants.
Basic Ingredients to Make Potting Soil for Indoor Plants
Sphagnum Peat Moss
Most of the potting soil is either peat moss or coco coir. Most indoor plant care kits come with potting soil, are inexpensive, and are available easily.
This stable material takes a long time to break down. As the bulk of potting soil, peat moss provides primary support to the plant.
It is well-aerated, stays wet, and drains excess water, ideal for gardening purposes. Another advantage is it is lightweight so it does not add a lot to the weight of the pot like garden soil.
However, it is low in nutrients and comes with an acidic pH which is not so plant-friendly.
Adding ¼ cup of lime for 6 gallons of peat moss reduces the acidic range from 3.5 to 4.5 to neutral or alkaline.
Its nutrient deficiency is addressed by adding further ingredients and fertilizers to the mix.
Coco Coir
Though little expensive than peat moss, it has higher durability and some nutrient value. The rest of this coconut by-product function is similar to peat moss. You either use coconut coir or peat moss as a base ingredient in potting soils.
Its pH is close to neutral, so there is no need to add lime. Also, as it comes in compressed bricks and expands when you add water, it is easier to store as a raw material.
Perlite
It is a volcanic rock mineral — mined and heated for expansion, making it porous. As a result, it is sterile, lightweight, and useful for improving drainage and retaining 3 to 4 times its weight.
Vermiculite
It is finer than perlite and is a mined mineral deposit. Besides adding minerals such as magnesium and calcium, it is also useful in water retention.
Recipe Mix to Make Potting Soil for Indoor Plants
We’ve discussed the ingredients to use and blending them in the right ratios below:
All-Purpose Potting Soil - Vegetables, Flowers, and Tropical Plants
Six gallons of peat moss/coco coir
¼ cup lime (when using peat moss)
Six gallons compost
1.5 cups of organic fertilizer
4.5 gallons perlite
For Potted Trees and Shrubs
Three gallons peat moss/coco coir
Two tablespoons of lime (when using peat moss)
Three gallons compost
2.5 gallons composted pine bark
2.5 gallons coarse sand
Three gallons perlite
One cup granular, organic fertilizer
For Succulents and Cactus (Low-Maintenance Indoor Plants)
Three gallons peat moss/coco coir
Two tablespoons of lime (when using peat moss)
Two gallons coarse sand
One gallon perlite
One gallon vermiculite
For Seed Starting
Two gallons peat moss/coco coir
Three tablespoons of lime (when using peat moss)
Two gallons vermiculite
One gallon coarse sand
Supplies Required to Make Potting Soil
Large bucket for mixing
Measuring container
Soil scoop
Safety mask
Water (For expanding coco coir)
Once you gather your ingredients and the supplies, it's time to mix.
Mixing Process
Put all your ingredients according to your recipe into the large bucket and mix it thoroughly. Use the soil scoop or your gloved hands for mixing. And there you go! Your potting soil is ready for use.
Add a little fertilizer to the mix if you use it for repotting. No need to do so if you are going to store it. It is always best to prepare the potting soil fresh.
Commercial Potting Soil Mix Vs. Homemade Potting Soil Mix
Commercial potting soil mix is convenient but comes at a high price. Also, every time you change a brand, the results are different.
When you find your perfect fit, it helps you grow healthy plants. But usually, users find at least one of the below issues.
Not enough drainage — damages plant roots due to stagnant water
No proper water retention — reduces water supply to the plant
High sand content — not suitable for all plant types
Large sticks or rocks — obstructs the growth of roots
You can balance homemade potting soil mix for all the above based on your plant needs.
Proper moisture retainment, good drainage, and a fluffy potting mix will give you good results.
Benefits of Making Your Potting Soil for Indoor Plants
Reduces your cost significantly than commercial mixes
Easy to mix
Can tailor it for different plant needs
Provides proper medium necessary for plants to thrive
Better control over drainage and moisture retainment in comparison to garden soil
Lightweight, consistent, and easy to handle than garden soil
Useful Tips
Buying the ingredients in bulk helps in cutting costs.
Keep the three major ingredients available at all times to make potting soil for indoor plants fresh when required.