Microgreens rely on a healthy soil environment to grow quickly and produce healthy nutritious leaves. Make sure to choose a potting mix that provides nutrients, drainage, and moisture retention to avoid any of the common microgreen growing issues.
The best soil for microgreens is a high-quality nutrient-dense soil made up of a mixture of 80% organic material, such as peat moss and coconut coir mixed with 20% perlite. This concoction serves as a good base and will improve the growth of your microgreens exponentially!
These five soils are great choices and all contain the necessary nutrients that your indoor plants will need:
- Black Gold All Organic Potting Soil
- FoxFarm Happy Frog Potting Soil
- Miracle-Gro Expand ‘n Gro Concentrated Planting Mix
- Espoma Organic Potting Mix
- Minute Soil Compressed Coco Coir Fiber Grow Medium
*If you’re in a hurry, I’d recommend the FoxFarm Happy Frog Potting Soil as the best one. This soil is beloved by experienced and novice microgreen growers alike and is full of nutrients that will produce several yields of healthy greens with no additional fertilizer needed. It has incredible water retention so you don’t have to worry about it drying up too quickly between waterings or pausing the progress of the microgreens.
Black Gold All Organic Potting Soil
This potting soil is all-natural and organic, making it perfect for those who want the healthiest microgreens possible. It is made in the western region of the United States and consists of peat moss, aged bark, compost, earthworm castings, perlite, pumice, and organic fertilizer.
This soil is extremely fertile and you won’t require any additional nutrients when using it for your microgreens. Customers report that it is a smooth even blend that doesn’t contain large chunks of plant material. This makes it ideal for small-scale and container gardening.
Some have reported pest and mold problems with this soil, particularly fungus gnats. This may be caused by the added organic fertilizer. Spraying your soil with a hydrogen peroxide and water mixture will minimize this problem if you have an issue. Baking your soil (30 minutes at 160 degrees) should also correct any pest problems.
FoxFarm Happy Frog Potting Soil
Happy Frog Potting Soil is an excellent beginner’s blend that provides the perfect nutrient balance to grow almost any plant. This soil is designed specifically for the container garden which means it’s perfect for your microgreens.
FoxFarm focuses on creating a “living” soil that is full of microbes (mycorrhizal fungi) that both support and defend your growing environment. They also make sure their soil is in the proper pH range, which is important for healthy microgreen growth.
Happy Frog potting soil guarantees that when used with proper watering and care instructions, the ingredients in the potting soil will help prevent transplant shock. It’s packaged in a convenient 20-quart size bag which makes it ideal for all your gardening needs.
Miracle-Gro Expand ‘n Gro Concentrated Planting Mix
Miracle Gro is a well known brand and this potting mix makes it easy for all levels of indoor growers to create healthy microgreens effortlessly. This soil comes with enough nutrients to feed your plants for up to 6 months, which means you can reuse it to create several new batches without having to buy more potting mix.
This soil also expands up to 3 times its size when water is added to it, so it is best to moisten the soil in a separate bucket before spreading it into your microgreen trays. This compressed soil will be easier to store in an apartment or small gardening space.
This material is very fine and light with high moisture retention and a good loose structure that allows for maximum airflow. This will make sure that the root systems in your plants stay healthy.
Espoma Organic Potting Mix
This potting mix consists of completely organic peat moss, peat humus, perlite, and dolomitic limestone. It is pH balanced and can provide an ideal environment for your microgreens. This makes it a great choice for beginner gardeners, or those working with a variety of plants who want consistent results.
Customers have noticed germination takes up to half as much time with this fertile soil, making t a great choice for someone who wants to harvest their microgreens quickly or create large yields. Those who have transferred previously potted plants into this soil have reported a quick improvement in the health of their plants as well.
Like most soils that are organic and aren’t sterile, there is a chance that microorganisms or pests may be attracted to the soil. You can use hydrogen peroxide or sterilize your soil through baking to minimize these issues.
Minute Soil Compressed Coco Coir Fiber Grow Medium
This soil alternative uses compressed coconut coir fibers as a growing medium for plants. This organic material is made out of coconut shell husks and fibers. It holds water and oxygen well, is organic, and is a renewable material, making it environmentally friendly.
This potting mix is the best option for those who want to cleanly store their gardening supplies in a small space. Each coconut coir soil pellet expands up to 15 times when moistened! This company has focused on creating a manageable soil option for urban gardeners, container gardeners, and microgreen growers.
The Anatomy of Microgreens Soil
There are some key factors to consider when choosing or making a soil for your microgreens. By preparing your soil to be nutrient-rich, airy, and moist, you will increase the lushness of your yields and will be able to harvest much more quickly.
Nutrients are necessary for healthy and thriving microgreens. If your soil lacks nutrients (such as nitrogen, potassium, or phosphorus), your microgreens may “thin out” and grow slowly. In addition to getting a nutrient-dense soil, you can consider adding a fertilizer or a beneficial soil organism to your potting mix.
Fluffy and airy soil is also helpful for growing microgreens. This helps to protect the roots and prevent root rot by making sure your plants don’t sit in stagnant water. If your potting mix is too dense, you can add some coconut coir, perlite, or peat moss to lighten it up. Make sure your containers have drainage holes as well.
Even though we want fluffy soil that promotes water drainage, it is also important to have water retention in potting mix as well. A well-drained soil that can stay moist will create the ideal conditions for your microgreen’s root systems. Perlite and vermiculite are great additives if you need more moisture retention in your potting mix.
What Is Potting Mix Made Of?
Potting soil is a mixture of peat moss, perlite, sand, compost and other ingredients to provide water and aeration.
Peat Moss
The most common ingredient in potting soil is sphagnum peat moss. Sphagnum peat comes from the decomposed remains of sphagnum moss, a plant that grows in bogs and is usually harvested by hand. It holds water well while providing good drainage and also fertilizer for microgreens.
Perlite
Perlite is a volcanic glass that was once used as an insulator. It makes soil lighter and helps retain water. Perlite is often mixed with vermiculite, a mineral similar in makeup to mica, which has small spaces between its crystalline structure.
Sand
Sand is primarily used as drainage – to allow excess water to flow out of the pot.
Compost
Compost is a mixture of decayed plants, manure, and other organic matter. It supplies nutrients for growing plants and increases aeration in the soil. Other Components: Potting soil may also contain peat humus, which is a partially decomposed form of peat moss; composted manure, which adds nitrogen to the soil and helps loosen clay-based soils; and sand, vermiculite, or perlite for drainage.
How To Use Your Soil
Select And Prepare Your Soil
Choose a soil to use for your microgreens. If you are worried about microorganisms, mold, or pests, you can bake your soil in the oven before use to make sure it is sterile. I would only recommend doing this if you’re worried that your soil is contaminated because the heating process can reduce the benefits and nutrients present in the potting mix. You will want to heat your oven to 160 degrees and bake the soil for 30 minutes. This will eliminate fungi, bacteria, worms, and viruses.
Saturate Your Soil
Saturating your soil before placing it in the microgreens tray will prevent a big wet mess. It also allows you to comb through your soil for any unwanted large pieces of plant material or earth.
Pour your soil into a bucket and slowly add and mix in water. Make sure that you don’t oversaturate the soil, create pools or water, or reach a mud like consistency. As you slowly work the water into your potting mix, pick out any rocks or small twigs that you may find.
Add Any Fertilizer Or Nutritional Boosts
It’s usually not necessary to provide fertilizer for your microgreens. Your potting mix will likely remain fertile for several batches of plants before needing a nutrient boost. However, if you choose to add it, you may experience denser and healthier yields that grow faster. Make sure to add them into the bucket and stir well for an even distribution.
Fill Your Container With The Moistened Soil
Lift or scoop the moistened soil out of the bucket and into your microgreens container. Don’t push the soil down or condense it. Leave about a quarter-inch of space from the top of the container.
Add Your Seeds and Loosely Cover With Soil
You can soak your seeds overnight to help ensure they will sprout. When your soil is ready and in your tray, go ahead and spread your seeds evenly over all of the potting mix. Sprinkle a light layer of soil on top of the seeds.
Soil Alternatives for Microgreens: Coconut Coir & Other Mediums
Many people prefer using soil alternatives for their microgreens. These materials are called growing mediums, and can provide a clean, easy, and effective solutions for indoor gardeners. In order to keep your microgreens growing strong, it’s important to research a medium well before you purchase it.
Growing medium, also known as media, is essential for healthy microgreen seeds starting. You can use seed starting soil as a medium, as well as several other organic materials, such as growing mats.
There are many options when it comes to choosing a growing medium for your plants. Here is a short list of some of the most popular materials you can try.
Here are some of the most popular alternatives to soil:
Soil
A good microgreen soil is the most common choice for microgreen growing as well as seed-starting in general. The best soil for microgreens is nutrient-rich and good at holding moisture for your plants.
Coconut Coir
Coconut coir is a natural, agricultural by-product that is composted and processed into a soil conditioner. Coir has been used as a substrate for growing microgreens because it provides the environment with just enough water retention without being too wet. That allows for better air circulation and faster drainage when properly hydrated. It also helps to ward off any insects that may be attracted to the food garden and provides natural nutrients for the plants.
Coconut coir is derived from the outer husks of coconut shells. This is the foam-like structure that surrounds and protects a coconut, which many people know as ‘coconut foam’ or ‘coco peat’. It can be found in three grades: first grade being the highest quality and third grade being lowest. Coir is hydrophilic, meaning that it attracts water and readily absorbs moisture.
Burlap
A new study has found that burlap can be used as an inexpensive and effective substitute for the traditional soils often used to grow microgreens.
The burlap was shown to provide essential nutrients for microgreens growth, such as nitrogen and potassium which are important contributors to greening up leaves and obtaining high yields of quality produce. This is also cost-effective because burlap is less expensive than other soil alternatives. It drains easily and has high water retention, which means there is less water waste, and it also prevents over-watering of your microgreens.
Rockwool
Rockwool is a sterile and porous non-degradable material that is made out of limestone and granite. It’s good for growing microgreens because It holds water very well, has great oxygen retention, and comes in a variety of sizes and shapes. Your microgreen seeds have a good chance of avoiding dryness. Like any material, it has drawbacks as well. It is not pH neutral, creates dust particles, and can be nearly impossible to dispose of in an environmentally friendly way.
Vermiculate
This substance has great moisture and nutrient retention capacity. However, it is possible that it may hold too much water, and is an expensive choice. Vermiculite is not intended to be used in place of soil but may work in combination with other materials such as potting mixes and topsoil when used to grow microgreens.
Check out this article for my top picks for microgreen mediums.
How Do You Make Soil for Microgreens?
To make your own microgreens potting mix blend, you will need:
- 1 part vermiculite
- 1 part perlite
- 1 part compost
- 4 parts peat moss
This microgreens soil blend will provide the appropriate amount of drainage, water retention, and fertilizer for your microgreens.
Another common method for making a customized microgreens soil is to mix 1 part of potting soil with 1 part of seed starting mix. This blend will provide ample nutrition for your plants.
Is Miracle Grow Potting Soil Good for Microgreens?
Miracle Grow potting soil is safe to use with any edible food you are growing. Make sure to double-check any specifics on your bag of potting soil just in case your specific variety is meant for other types of plants.
If you’re using Miracle Grow potting soil for growing microgreens, first consider what’s in it. It’s a combination of peat moss, vermiculite, perlite, and fertilizer. Peat is highly acidic and holds a lot of water, which is why it’s perfect for growing plants indoors. It can also hold up to 50 times its weight in water.
The high acidity and the ability to hold so much water make Miracle Grow a good choice for starting seeds but not necessarily the best choice for microgreens over the other suggestions in this article. However, many people swear by this product and get amazing results with it.
Some other benefits of using Miracle Grow include :
- Nutrients are easily available to microgreens plant roots.
- The soil mixture drains well but doesn’t dry out quickly, making it a good choice for container gardens.
- It can be used repeatedly because the nutrients are stored in the peat and not leached into the container.
Summary
Many people are interested in growing microgreens because they are simple, easy, fast, and fun. Choosing the best soil for your microgreens will provide a strong foundation for healthy and abundant yields.
The best way to find out which potting mix, soil, or soil-free medium is best for your microgreens is by experimenting and finding which method works best for you. It will be worth it when you’re eating fresh healthy produce grown right in your own home!
Tell Me How It Goes!
What soil have you used for growing microgreens and what materials do you think work best? Let us know in the comments section below so we can all discover the best soil for microgreens together.
