Fertilizer for Microgreens: What You Need to Know!

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Microgreens Growing

Growing plants can be challenging, but the good news is that microgreens are one of the easiest kinds of plants to grow. They can be grown indoors or outdoors by novice and expert gardeners alike. When starting a microgreen garden, gardeners may wonder if it will require fertilizer.

Do microgreens need fertilizer? It depends on the medium used to grow them. Gardeners growing plants in high-quality soil do not need fertilizer. Fertilizer can also be replaced by using compost in the soil. However, when using a soilless medium or a hydroponic growing method, fertilizer may be necessary for added nutrients.

When it comes to adding fertilizer to microgreens, there isn’t a right or wrong answer. Every gardener is likely to recommend something different. In this article, we will discuss when fertilizer should be added to microgreens and why fertilizer shouldn’t be the first option to give nutrients to plants.

Do Microgreens Need Fertilizer?

The simple answer is no; it is not necessary to provide fertilizer to microgreens when they are growing in high-quality soil. This is because the soil itself will possess enough nutrients to keep microgreens growing strong and healthy.

On the other hand, when using a soilless medium or hydroponic gardening, gardeners may need to add fertilizer. With these growing mediums, microgreens won’t be getting any nutrients directly from the soil, which can lead to failure to thrive in many plants. These types of mediums are regularly used for microgreens, but they are a bit more difficult to deal with.

What Kind of Soil do Microgreens Like?

Plenty of soil options are out there when it comes to microgreens. It may be surprising that three different ways exist to grow microgreens, some of which include soil and some that do not. Gardeners who choose to use soil can buy soil from a store or make it homemade.

Store-Bought Soil

It is important to buy high-quality soil when not using homemade. One of our top soil recommendations for organic microgreen gardening is Burpee Natural Organic Premium Grow Mix (Amazon Link).

This must-have soil mix immediately releases essential nutrients to the microgreens and will continue to provide these nutrients for up to three months. This is perfect for microgreen gardening because high amounts of nutrients are only needed for a few short weeks. This decreases the worry about whether microgreens have enough nutrients.

With Burpee Natural Organic Premium Grow Mix, you will get all these added features:

  • A soil that is enriched with Burpee plant food. It helps to produce succulent microgreens that are bright, bold and delicious.
  • Perfect for growing in containers. This is great news for the indoor microgreen gardener.
  • Formulated using coconut coir. This is a renewable source that helps with maintaining proper moisture levels, which is very beneficial because microgreens are very picky about their water levels.
  • 100% organic. Because the soil is completely organic, it’s ideal for a gardener who is going the organic route and doesn’t want to worry about harmful ingredients.

As shown, fertilizer is not necessary when opting for a soil mix like this. It offers plenty of useable nutrients for microgreens throughout the entirety of their lives.

Do-It-Yourself Soil

If you are an avid DIY person, then the thought of buying a premade soil mix might not be so appealing. But don’t worry – there are other options when it comes to providing the right soil for microgreens. It’s very easy to create a top-notch soil yourself.

The Three Essential Elements of Quality Soil

Making soil is simple, but keep in mind that three essential elements are part of every great quality soil, whether it is bought in-store or created by hand. “The Best Soil for Microgreens,” a blog from MicroVeggy.com, explains that the three things all quality soil needs are nutrients, water retention capabilities and airflow.

  • Nutrients

Whether growing a larger-than-life fern tree or tiny microgreens on the windowsill, every plant needs nutrients to grow. Microgreens absorb their nutrients directly from the soil, so it’s important to have enough nutrients on hand. Without proper nutrients, microgreens will be thin and grow slowly.

  • Water Retention Capabilities

Microgreens are picky about their water. If they don’t get enough water, they won’t grow much and are prone to growing mold. The water retention capabilities of soil are important because it needs to be able to hold some water to keep the microgreens happy. Just make sure the container has enough drainage holes, so accidental overwatering does not occur.

  • Airflow

Ventilation is also a crucial element in growing microgreens. This includes the soil, not just the air around the microgreens. Adequate airflow will allow microgreens to ‘breathe’ and help with water drainage, which is crucial when growing difficult microgreens.

A Recipe for Quality Soil

The best way to make sure that microgreens are receiving all the nutrients they need is to follow this ideal microgreen soil recipe:

  • Four-parts peat moss
  • One-part vermiculite
  • One-part perlite
  • One-part compost (or worm castings)

With this blend, gardeners should have no problem with microgreens not having enough nutrients to thrive. Keep in mind that the bulk of the nutrients is going to come from the compost added. Compost is extremely important in homemade soil.

If compost is not added in the homemade soil, then fertilizer may be necessary. This is because, without compost, a sufficient amount of nutrients is likely not available for microgreens to absorb and grow. When making soil, it is necessary to use either compost or fertilizer.

We have written an entire article on our own DIY Potting Soil and Seed Starting Mix which would work great for microgreens too!

What About Soilless Mediums and Hydroponic Gardens?

The best time to use fertilizer when growing microgreens is when using soilless mediums or hydroponic gardens. This is because no soil is present to provide nutrients to the microgreens; therefore, they may end up lacking nutrients and the plants will not yield as big of a harvest.

GroCycle.com’s article “What Growing Methods are Available for Growing Microgreens” explains that, while soil is the preferred method of growing microgreens, it is not the only viable option. Some microgreen gardeners have even claimed that soil is ‘too messy’ for certain microgreens such as basil, and harvesting is easier using methods other than soil.

Soilless Mediums

Microgreens Hemp Mat
Credit: Biodegradable-pots.com

It’s possible to grow microgreens in a soilless medium. As the name suggests, in a soilless medium, no soil is present, whatsoever. It may seem like a crazy way to grow a plant, but it works when it comes to microgreens.

The most used soilless mediums include coconut coir, hemp mats and vermiculite.

  • Coconut coir is directly made from coconut, and the main benefit of using it is that it can’t be overwatered. This is convenient since microgreen growth can be disrupted by too little or too much moisture.
  • Vermiculite, on the other hand, is a mineral that is mined from the ground. With this type of soilless medium, pH levels or mold are never a factor because vermiculite has a natural pH balance that cannot be disturbed and is not prone to mold. This is a huge benefit as microgreens can become molded quickly.

Vermiculite is frequently added to soil to enhance its overall airiness, pH balance, and resistance to mold. It can also be used alone and has a wonderful success rate with microgreens.

  • Hemp mats are great for growing microgreens since they distribute water evenly, which means the microgreens won’t need to be watered too often. Hemp mats offer a great soilless medium for microgreen growth, but they can rip easily.

Hydroponic Gardening

True Leaf Market Micro Mat
Credit: Get all your microgreens products at True Leaf Market!

When it comes to growing microgreens, another option is to grow hydroponically. This means that the microgreens are being grown in nothing but water, which is typically loaded up with essential nutrients and minerals to help with the overall growth of the microgreen.

Setting up a hydroponic growing tray for microgreens requires close attention to every detail and following these steps:

  1. Balance the pH of the water. It should be between 5.5 to 6.5 because microgreens grow best at a pH level of 6.
  2. Pour 2 cups of the balanced water into a tray and swish the water around to distribute it among all the channels.
  3. Place a growing pad on top of the water and press gently, saturating the growing pad.
  4. Using a spray bottle of the pH balanced water, mist the top of the growing pad evenly and make sure it is laid flat.
  5. Sprinkle seeds directly onto the moistened growing pad.
  6. Mist the seeds with the pH balanced water. Ten to twelve sprays will usually get them sufficiently wet.
  7. Grab another empty tray and mist the inside of it four or five times.
  8. Place this empty tray on top of the growing tray to act as a humidity dome and black-out top.
  9. Store seeds in an area that stays between 65- and 75-degrees Fahrenheit.
  10. Mist every twelve hours.
  11. Uncover the growing tray after four or five days.
  12. Place the microgreens into a light source.
  13. Check on them daily. They should be ready to harvest between day seven and day ten of growth.

(Source: True Leaf Market)

Do Hydroponic Gardens Need Fertilizer?

If the microgreens are starting to wilt, then adding fertilizer is recommended. Since the microgreens aren’t receiving any type of nutrients from the soil, they will likely need a nutrient source during their growing period.

The good news is that it is possible to get by without needing any special fertilizers or other equipment since microgreens grow very quickly using the hydroponic method. If any sign of sickness or lack of nutrients is noticeable in the microgreens, such as pale, yellowing leaves, or a plant that is completely falling over, then spraying some fertilizer may provide a quick fix.

Corey from CoreysCave YouTube channel did an experiment with hydroponic microgreens. He compared trays with no fertilizer and trays with some added fertilizer dissolved in the water. He was able to grow microgreens in both cases, but the trays with fertilizer added gave him a much bigger harvest.

Hydroponic Microgreens: Do Nutrients Matter?

Corey used General Hydroponics MaxiGrow (Amazon Link) in his experiment and said a bag will last quite a long time because it doesn’t take much fertilizer per tray.

What is Fertilizer?

Fertilizer is a material that is added to soil, soilless mediums, or hydroponic gardens to increase the number of nutrients that are readily available for a plant. It can come in both natural and synthetic forms.

Fertilizer can provide a multitude of essential nutrients that are crucial to plant growth. The most important nutrients found in fertilizer include nitrogen, phosphorus and potassium. Because these three substances are the building blocks for the vitality of a plant, they must be readily available.

Types of Fertilizers

From potassium sulfate to animal manure, many different types of fertilizers are available on the market, but they are not all intended for use on microgreens. Even though microgreens are known for being one of the easiest plants to grow, it is still possible to ruin them.

If you are thinking about adding fertilizers to your microgreens, make sure you are choosing the right kind. True Leaf Market recommends the following three fertilizers for use with microgreens:

  • Azomite. This unique powdered fertilizer is made from volcanic ash and is loaded with a collection of earth elements as well as minerals. To use Azomite in a microgreen garden, incorporate it into the garden before planting. This gives the Azomite fertilizer plenty of time to break down in the soil, making the nutrients immediately available to the microgreens.
  • FloraGro. Another great option is any water-soluble fertilizer such as FloraGro. This type of fertilizer contains a multitude of nutrients that will help microgreens grow big, strong and plentiful. With this type of fertilizer, it is recommended to wait until the microgreens are beginning to pop out of the soil before applying. Mix with usual water and water plants as usual.
  • Liquid Kelp. The last option is liquid kelp, which should be reserved for soilless mediums and hydroponic gardens. This is because a high amount of nutrients are found in this type of fertilizer, and it can be easily overdone. Liquid kelp also provides several benefits, such as high levels of cytokinin, which is directly related to plant growth.

Is Fertilizer or Compost Better?

If a gardener is using soil to grow microgreens, then it is not technically necessary to use fertilizer – unless, of course, the microgreens are lacking in health or soil without any plant food or compost is being used. But which one is better? Lauren Miller’s article “Compost vs. Fertilizer” reveals the pros and cons of both compost and fertilizer.

Fertilizer Advantages and Disadvantages


Any time a plant is noticeably looking a bit ‘down’ or otherwise headed for death, then spraying it with a little fertilizer will give it a big dose of nutrients to regain strength. This is the reason fertilizer it is so commonly used, especially on plants that don’t seem to be getting enough nutrients from their soil. If a gardener is looking for a quick fix, then he or she will find it with fertilizers.


The biggest issue with fertilizers is that they don’t fix the root of the problem. If a plant, such as a microgreen, is not thriving due to lack of quality soil, then fertilizer is going to feed the plant and mask the main concern. Fertilizers can also be bad for the environment, so keep an eye on the ingredients when shopping around.

Another issue with fertilizers is that it can be overdone very quickly. Too much fertilizer is a bad thing. When microgreens are overfertilized, it may do more harm than good.

Here are six symptoms that too much fertilizer is being used in a microgreen garden:

  1. The leaves are turning yellow and the entire plant is wilting.
  2. The microgreens are turning brown.
  3. The roots of the microgreens are turning black or brown.
  4. Overall growth has slowed down or stopped.
  5. Leaves have become droopy.
  6. The crust of the fertilizer begins to show up on the surface of the soil.

Compost Advantages and Disadvantages


Compost is commonly referred to as ‘black gold,’ and for good reason, too. Compost is a collection of decomposing organic materials that enhance the soil itself. It is combined with soil or other ingredients, allowing the roots to absorb the nutrients right from the source. The compost will continue to decompose and provide nutrients while microgreens are growing.

Another major benefit is that compost is much cheaper than fertilizer. This is especially true when making compost at home.


Little to no disadvantages are evident when it comes to compost. Perhaps the only thing that may sway someone from using it is that it takes lots of time to make it. A gardener will typically spend three to six months making proper compost. The option of buying compost in the store is typically available, too.


Fertilizer is not necessary when using a high-quality soil in a microgreen garden. If soil needs more nutrients, compost is a better option. When it comes to soilless mediums and hydroponic gardening, fertilizer may be necessary because there is no soil for the microgreens to absorb nutrients, and they may require assistance along the way.

If you are interested in getting started with microgreens or are looking for a reliable online store for seeds and supplies at a great price, check out our affiliate at True Leaf Market. TrueLeafMarket.com – Microgreens Seeds, Kits & Supplies

Check out Our Favorite Products page to find everything you might need to help make your garden a success!

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Corey Leichty

Hi, I’m Corey and I love using gardening as a way to provide food for my family, learn life lessons alongside my wife, Andrea, and teach life lessons to my two sons. Do you have gardening questions? Not finding what you are looking for? Please feel free to Ask a Question (Click Here!) and I will get back with you as soon as I can!

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