Why Should I Make a Seed Starting Mix?

By Jennifer Poindexter

Are you tired of purchasing your garden supplies? Are you interested in making your own seed starting mix?

Then allow me to help you with your DIY gardening needs. Whether you’re trying to garden more organically, or your goal is to save money, these seed starting mix recipes should help you.

I’m also going to share with you a few reasons why you might consider making a seed starting mix instead of soil.

Plus, you should understand the importance behind key ingredients to these recipes. If you’re ready to dive into your options for seed starting mix, here’s everything you should know:

When creating your own seed starting mix, you may notice one ingredient is missing. That ingredient is soil.

Why make a seed starting mix instead of using soil? There are quite a few good reasons to go soilless when starting seeds.

The first reason is when you skip using soil, you also skip quite a few fungal issues as these diseases don’t thrive in potting mixes.

One of the greatest threats to seedlings is damping off. Since seed starting mix doesn’t hold moisture like soil does, there’s less chance of your seedlings becoming oversaturated and developing this fungal issue.

The next reason why you might prefer a soilless mix for starting seeds is it’s not as heavy or dense as soil can be.

This consistency helps the mixture drain better, and seeds don’t need soil at the beginning of their life cycle anyway.

In fact, the first two weeks in the seed starting journey, your seeds have all they need within themselves. As they sprout, the ingredients in your seed starting mix (like compost) provide all the nutrients the seedlings need.

If you’re on the fence between potting soil and a seed starting mix, these are a few things you might want to consider when making your decision.

Important Ingredients of Seed Starting Mix

Each recipe for a seed starting mix is a little different, but they also contain similar ingredients. It’s important to understand what each ingredient does.

This way, you may change the recipe (as needed) to best suit your preferences when gardening.

The first common ingredient in seed starting mix is perlite. This ingredient is what helps your mixture drain adequately.

If you’re making a seed mix, and you notice it’s retaining more moisture than you’d like, the mixture might need more perlite.

The next ingredient is coir. This is sometimes substituted with peat moss. However, we’ll talk a little later about why some gardeners are turning to coco coir.

Coir is a byproduct of processed coconuts. It’s used to aerate the mixture while also helping to retain necessary moisture.

Our final common ingredient found in most soil mixes is vermiculite. This is a common mineral that occurs naturally. It’s another ingredient used to help retain moisture in the mixture.

As we all know, gardening is all about balance. You must pick a growing medium that drains away unnecessary moisture while still being able to retain the amount the plant needs to thrive.

Now that you know what each ingredient does in a seed starting mix, let’s talk about measuring ingredients for each recipe.

How Do I Measure Ingredients for Seed Starting Mix?

In many seed starting mix recipes, you’ll see it as “one part ________” or “two parts _____________.” A part is a general method to measure different ingredients.

If you’re using a one-cup measuring utensil, one part would be one cup. However, I realize not everyone enjoys measuring.

In what you’ll read today, you’re being provided percentages. This way, if you’re someone who likes to measure, you can still use your measuring utensils.

Yet, if you’re someone who likes to free-pour ingredients into a wheelbarrow or container, when making a seed starter mix, you can generally tell if you’ve filled something up by 50%.

In this case, how you choose to measure is up to you. Though these are recipes, they’re negotiable. You can change them to suit your plants’ needs along the way.

Recipes for Seed Starting Mix

I’m going to share four DIY seed starting mix recipes below. You may try them all, but if you’re new to gardening, it might be best to start with the recipes which include ingredients you already have or are readily available to you.

Making your own seed starting mix isn’t difficult. Let’s begin by reading through each recipe, so you may choose the one that best suits you.

Traditional Seed Starting Mix

You will need:

50% compost

20% peat moss

10% perlite

10% vermiculite

Pick a large enough container to support the amount of ingredients you use. This recipe can be adjusted up or down, depending upon the amount of seed starting mix you’re making.

Begin by ensuring your compost is easy to handle. It should look like well-sifted flour. You don’t want any large clumps to go into this mix.

When your compost is ready, pour the other ingredients into the container along with the compost. Use a hand trowel, shovel, or your hands to mix the ingredients. The seed starting mix is ready to use once everything is well mixed.

Three-Ingredient Seed Starting Mix

For those of you who feel less is more, this recipe is for you. It only contains three basic ingredients.

You’ll need:

80% peat moss or coco coir

10% vermiculite

10% perlite

If you use coco coir, ensure you soak it prior to use. Once it’s workable, place all the ingredients in a container and mix well.

Skip the Peat Moss Seed Starting Mix

As I mentioned earlier, there are some gardeners who are shying away from using peat moss in their garden. The reason being is the controversy surrounding how this product is harvested.

There’s concern that it might damage the ecosystem where peat moss grows. Therefore, many gardeners are opting out of using it in an effort to stop the harvesting process.

For this recipe, you will need:

45% compost

45% coir

10% perlite

If you’ve ever worked with coco coir you know it must be soaked for it to become workable. Ensure the coir is well-soaked prior to mixing this seed starting mixture.

When the coir is ready, gently pull it apart with your hands and place it in a container. Add the other ingredients and mix well. You may use the product once everything is properly combined.

Simple Seed Starting Mix

Our last seed starting mix recipe is an even easier version of one of our previous recipes. You’ll use all the same ingredients as the three-ingredient seed starting mix.

However, it’s easier because there’s no measuring. Whatever tool you use to measure your ingredients, you’ll use equal amounts of each item listed below.

Here’s what you’ll need:

Peat moss or coco coir

Vermiculite

Perlite

Ensure equal amounts of each ingredient go into your mix, and you’re good to go. Remember, soak your coco coir (if using it) to ensure it’s workable.

We hope this information will help you as you try to garden organically or on a budget. Making your supplies is not only frugal, but it also gives you more control over your gardening experience.

Even if you have a preference between coco coir and peat moss, there’s a recipe here to accommodate you. Pick the recipe that best aligns with your availability to resources (or your convictions) and enjoy a new gardening experience.