This is Microgreens 101, your guide to choosing the best growing medium for optimal growth.
Why the Growing Medium Matters So Much
Let’s begin by discussing why it’s so important to choose the best growing medium for microgreens. Microgreens are easy to grow, but they do have some basic needs. And the growing medium plays a role in all of them.
The growing medium is what gives the growing microgreens the nutrient content and structural support they need for optimal growth and health. It should also provide good drainage and aeration, to prevent root rot, mold, and fungal diseases.
Without an adequate growing medium, microgreens will fail to thrive.
Soil as a Growing Medium
Newcomers to microgreens often used soil as their default growing medium. They believe that, if it works for their houseplants and garden plants, it will work for microgreens. And this is not wrong. Soil can be used as a microgreen growing medium.
Soil provides microgreens with a stable growing base, and typically contains microorganisms that can boost microgreens’ health. It also offers good water retention.
The nutrient levels in different soil types can differ widely. Also, soil can harbor unseen but harmful pathogens. But if you choose well-draining, nutrient-dense soil, you’ll have an affordable, effective, and easy-to-use growing medium for your microgreens.
This is a cost-effective way to introduce microgreens into micro-habitats on campuses, too. And because microgreens take up so little space, they are ideal for growing on window sills in dorm rooms.
Safe and Sustainable Growing Medium
Alternative, soil-free growing mediums help indoor gardeners avoid the risks associated with soil. And one of the most popular choices among microgreens enthusiasts is coco coir. This is a byproduct of the coconut fiber industry, produced from the ground husks of the coconut’s inner shell.
Coco coir is the preferred growing medium of many microgreens experts. There are three main reasons for this:
- It is naturally pathogen-free and resistant to bacteria and molds.
- It offers superior water retention yet does not become waterlogged.
- As a byproduct of the coconut products industry, it is an eco-friendly and sustainable choice.
Coco coir does not contain nutrients, so you’ll have to add your own. It also needs to be hydrated and fluffed before using it as a growing medium. This means you’ll have more set-up time than you would with soil. But it’s an affordable, renewable product that is ideal for supporting microgreens during growth.
Specialized, Pre-Mixed Growing Mediums
Proprietary soilless mixes, specifically intended for optimal microgreen growing, are easy to maintain. These typically contain a blend of peat moss with perlite or vermiculite, and can also contain added nutrients.
Peat moss and vermiculite have excellent water retention properties and thus reduce the need for frequent watering. Meanwhile, perlite provides your growing medium with good drainage, which is crucial to avoid root rot.
Unfortunately, such pre-mixed growing mediums tend to be more expensive than most other growing mediums. But they all offer a simple yet optimal solution for beginner microgreen growers.
Home-Made Solutions
If you’re keen on eco-friendly gardening composting, you may want to consider a homemade solution for your microgreens, too. A blend of compost, worm castings, and other organic components like peat moss is an ideal growing medium for microgreens.
There are pros to using DIY composting options like this for growing microgreens. They are organic and sustainable and can also have a high nutrient density.
There are cons, too. The nutrient profile of DIY composting mixtures can differ greatly from batch to batch. There is always the risk of pathogens, necessitating careful screening of compost mixtures. But for microgreens growers who are already composting, this is also a readily available and affordable choice.
Microgreens are considered superfoods, nutrient-dense foods with superior health benefits. Composting is also ideal for growing other superfoods in your garden. Remember to check out our guide to superfood plants.
How to Choose the Right-Growing Medium
Regardless of which growing medium you choose, it must meet certain requirements for optimal growth:
- Growing mediums should be loose and light to make pressing microgreen seeds into them easy. Yet it should also offer developing roots stability and anchor them in place as the microgreens grow.
- Water retention is important to provide water to developing microgreens. But if the growing medium becomes too waterlogged and soggy, it can lead to root rot and other fungal diseases. Therefore, there should be a balance between water retention and hydration.
- If you use a growing medium that is guaranteed free of pathogens, you give your plants a good head start. They will be less prone to disease, and enjoy the conditions needed for optimal growth. Your microgreens will therefore be more suitable for human consumption.