Plants & Growing

DIY Potting Soil Recipes For Growing

green seedlings growing in pots on a wooden table
Written by Chris Lee

Whether it’s growing your own fruit and vegetables, making your own compost, or upcycling old household items to use as containers for growing, many gardeners nowadays are trying to become more self-sufficient, no longer wanting to rely on shop-bought products.

Needless to say, a lot of gardeners are also opting to make their own potting soil. It’s not as difficult as you would imagine, and can be a real money saver.

There are many more benefits that come with making your own potting soil including the fact that you know exactly what nutrients are in your soil, and you can tailor it perfectly to the plants you are working with. It also means you can be sure that you aren’t accidentally exposing your plants to any nasty chemicals like the ones you might find in herbicides and pesticides.

So, if you’re eager to start making your own DIY potting soil, then this article will tell you everything you need to know to get started. We’ll also introduce the best potting soil recipes for your garden.

What is potting soil?

Well, first things first, potting soil doesn’t actually contain any “soil” whatsoever and is, in fact, a soil-free mix commonly containing peat moss. Additional ingredients may include ground pine bark, sand, vermiculite, perlite and other added nutrients.

A mixture of ground perlite and vermiculite
Understanding the ingredients of potting soil is the first step

Essentially, potting soil is a medium in which to grow plants, herbs, fruit and vegetables in pots or other containers.

The perfect potting soil should be made from well-draining, porous materials between one-sixteenth and an inch in size. If the particles are too small, then the potting soil will not drain, whilst a potting soil containing particles that are too large will be unable to retain water.

The aim of the game is this: When you are watering your potted or container plants, the water should easily penetrate the potting soil, and any excess water should quickly and easily drain out.

Your DIY potting soil should be consistent, lightweight, and easy to handle. As mentioned, you can tailor your potting soil to the precise needs of your plants by creating your own unique blends –

  • If you are starting seeds or root cuttings, you will want to create a lighter, finer-textured mix.
  • For shrubs and trees, you will require a mix that consists of a high level of coarse sand or pine bark.
  • If you are growing succulents or cacti, then you will want to opt for a sandy and gravelly texture.
  • When it comes to growing containers of annuals, perennials, vegetables or tropicals, then a general, all-purpose potting mix is ideal.

Key ingredients for potting soil

Before you start creating your own DIY potting soil, it’s essential to familiarise yourself with the key ingredients that you will be working with and what part they play.

Sphagnum peat moss

This is the primary ingredients for the majority of potting soils. Sphagnum peat moss is a coarse, stable material that takes a long time to break down. Lightweight and inexpensive, it’s used to bulk up your mixture and also holds water well.

You will want to take care not to add too much Sphagnum peat moss as this can slow or even stop drainage. It also does not contain a lot of nutrients and has an acidic pH; you can add limestone to balance this.

Coir fibre

Coir or coconut fibre is a natural fibre extracted from the husk of the coconut. You will often see it used in brushes, doormats, and floor mats.

Coir is an excellent alternative to sphagnum peat moss, because it contains more nutrients and lasts longer. It is more expensive to purchase, but many gardeners feel it is a lot more sustainable.

Sand

Sand is a core ingredient to potting soil, and we recommend using builder sand (the type often used in construction) which is coarse and sharp and enhances drainage and aeration as well as adding weight to the mix.

Do take care not to go overboard on the sand as this can make the containers too heavy to move.

Perlite

Perlite is mined, expanded volcanic rock that has the appearance of white Styrofoam balls. Lightweight and sterile, perlite can hold up to four times its weight in water and is excellent for improving drainage.

It is more expensive for sand, but its qualities may make it worth the extra expense.

Vermiculite

Vermiculite is an excellent alternative to perlite. It is a mined mineral which is then conditioned with heat which causes it to expand into light particles.

Vermiculite increases the porosity of your potting soil, providing magnesium and calcium and increasing the water-holding capacity of your mix.

Fertilisers

You will need to add fertilisers to your peat-based DIY potting soil as the mix won’t naturally contain enough nutrients to support good plant growth. Stay away from synthetic fertilisers and instead opt for a natural fertiliser combining plant materials or animal by-products such as manure.

Limestone

As mentioned, adding limestone can help balance the pH levels in your potting soil. We recommend using about a quarter of a cup per every six gallons of your peat-based potting soil.

Compost

Compost is a wonderful addition to your DIY potting soil. It has an excellent capacity for holding water and is high in nutrients.

Including compost can play an instrumental role in promoting healthy plant growth – that said, we don’t advise using it for containers where you are start-seeding as it can be too heavy and prevent good growth.

Composted woodchips

By introducing composted woodchips to your homemade potting soil, you will increase the pore sizes, allowing for better water and airflow.

It is imperative to note that, although the woodchips are slow to breakdown, they can decrease the nitrogen within the potting soil and we therefore recommend supplementing with blood meal or alfalfa meal.

Gardener standing in trailer full of mulch
Composted woodchips can really seal the deal

Composted woodchips are an ideal ingredient for growing shrubs and perennials. Once you have purchased the woodchips, you will want to allow them to compost for a year and you should be turning the pile at least every three weeks.

DIY potting soil recipes for growing

Now that you have an understanding of what potting soil is and have familiarised yourself with the ingredients needed to create it, it’s time to start cooking!

We have picked out the best DIY recipes to help you make the perfect potting soils for your needs.

Making your own potting soil isn’t difficult and, as you come to understand it better, you will be able to manufacture whatever type you require for your pot plant growing needs.

You can use a wheelbarrow to mix your blends, or if you want to make blends in bulk, you could also use a compost tumbler or even a cement mixer.

General DIY potting soil for annuals, perennials, fruit and veg

  • 6 gallons of either sphagnum peat moss or coir
  • 4 and ½ gallons of perlite or vermiculite
  • 6 gallons of compost or chipping compost
  • ¼ limestone if you are using peat moss
  • 1 and ½ cup of organic fertiliser

DIY potting soil for seed starting

  • 3 gallons of either sphagnum peat moss or coir
  • 1 gallon of perlite
  • 1 gallon of vermiculite
  • 2 gallons of coarse, builders sand
  • 2 tablespoons of limestone if you are using peat moss

DIY potting soil for shrubs and trees

  • 3 gallons of either sphagnum peat moss or coir
  • 3 gallons of compost
  • 2 and ½ of coarse, builders sand
  • 3 gallons of perlite
  • 2 and ½ gallons of composted pine bark
  • 1 cup of organic fertiliser
  • 2 tablespoons of limestone if you are using peat moss
  • (optional) ¼ cup of cottonseed meal but only for shrubs and trees that require additional acidity

DIY potting soil for pot plants

  • 2 gallons of either sphagnum peat moss or coir
  • 1 and ½ gallons of perlite
  • 2 cups of coarse, builders sand
  • 3 tablespoons of limestone if you are using peat moss
  • 2 tablespoons of organic fertiliser

DIY potting soil for cacti or succulents

  • 3 gallons of either sphagnum peat moss or coir
  • 1 gallon of perlite
  • 1 gallon of vermiculite
  • 2 tablespoons of limestone if you are using peat moss

Go potty for DIY potting soil

Hopefully, this article has left you brimming with confidence to make your own DIY potting soil.

The wonderful thing about it is that, once you get into it, you can really change and adapt your own potting soil brand to perfectly suit the plants you are keen to grow.

Fresh herbs being grown in compact containers
Help your potted plants thrive with your own brand of potting soil

Learning to make your own potting soil will teach you so much about your potted plants, flowers, shrubs and trees and will give you a real understanding of their specific, individual needs.

Don’t be afraid to use a little trial and error; this is a rewarding process and will lead you to feeling like a much more confident and well-rounded gardener.

So go ahead and get mixing the perfect DIY potting soil for your potted plants.

About the author

Chris Lee

Chris is interested in nature and the good things that happen when people are in it. He is a freelance writer, with writing published about cycling, green living, and ways to make a difference without fundamentally restructuring your lifestyle.

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