How to Make Vermicompost Liquid Fertilizer From Worm Castings: Step by Step Guidelines for Success!

Vermicompost liquid fertilizer is a type of liquid fertilizer made from fermented worm castings. It is high in natural nutrients like nitrogen, potassium, and phosphorus that are essential for plant growth. It can be used as a foliar spray or mixed into the soil as an alternative to chemical fertilizers.

It can also be mixed with water in a one-to-one ratio and sprayed onto plants to fight leaf fungus, aphids and other pests. Vermicompost contains microorganisms that act synergistically with other microbes already present to break down organic matter faster than just adding vermicompost alone will do. One of the by-products produced during the composting process is carbon dioxide, which is a greenhouse gas that plants need for photosynthesis. The advantage of using vermicompost liquid fertilizer over chemical fertilizers is that it contains beneficial microorganisms and beneficial mycorrhizal fungi that help roots absorb nutrients from the soil more efficiently. This way, crops will not be as susceptible to insect pests and disease like plants treated with chemical fertilizer.

Vermicompost Liquid Fertilizer
Photo: Vermicompost Liquid Fertilizer, Credit: Instagram @ dianartini

In addition to being an excellent organic liquid fertilizer, vermicompost liquid fertilizer is a natural way of recycling waste and reducing waste. It improves soil structure, increases nutrient uptake and balances the nitrogen levels in the plant. Unlike chemical fertilizers that can be harmful to the environment if not properly handled, vermicompost liquid fertilizer can be directly applied without any harmful additives.

Are There Additional Benefits?

Besides gardening benefits, there are other benefits of using liquid worm castings as a liquid fertilizer.

  • Vermicompost is also useful for chicken parasites, fish and reptiles as well because it is high in protein and vitamins that are important to the animals’ health.
  • As an environmentally friendly fertilizer, it is also good for the soil health and can improve the soil structure of the earth.
  • Worm castings are rich in micronutrients that plants need to grow. One tablespoon of liquid vermicompost contains 10 times more micronutrients than a salad full of leafy greens.

Where Can I Purchase Vermicompost?

Although liquid worm castings can be collected from your own backyard, there are worm farms and garden supply stores that sell it at a cheaper price. The type used here is liquid vermicompost, a kind that contains approximately 95% protein by weight (about 20% higher than liquid manure). It also has a higher percentage of beneficial microbes and nutrients that promote plant growth.

How to Make Homemade Liquid Fertilizer

Homemade Liquid Fertilizer
Photo: Homemade Liquid Fertilizer, Credit: Instagram @

It’s easy and it’s a very effective way of fertilizing your plants, so what are you waiting for? Let’s get started!

Step #1- Assemble the ingredients:

For making your own liquid worm castings fertilizer you will need to have some suitable compost and earthworms, some water and something acidic, like vinegar or lemon juice. All of these items can be found at your local grocery store or garden center. You are also going to need something that will extract the liquid from the ingredients and that would be a juicer or a blender.

Step #2- Select the most suitable compost:

When selecting your compost you may use any kind you want, but if you want the best results, you should always go for high quality and well matured or over-ripened ones. They are rich in minerals and micro nutrients. If it contains a lot of organic matter, then the fertilizer will be more effective. Some examples would be manure composts, green garden waste composts and even kitchen scraps compost. In fact almost anything can be used for vermicomposting purposes and then converted into liquid fertilizer for plants. You may use any kind of compost but your worm castings will be more concentrated and effective if you use high quality compost.

Step #3- Add the acidic substance:

Once your compost is ready, all that you have to do next is add some acid to it. In order for the liquid fertilizer to be more effective, it should have a neutral pH level which is about 6.5, so for this reason we will need to add some vinegar or lemon juice – both of which have a pH of around 2-3. The vinegar can be added in small amounts, so as not to affect the overall pH level too much. However, you can use more if you prefer, or even try an alternative method of acidification, such as the process of electrolysis which works very well as it leaves no residues and is non-toxic. Using vinegar also makes it more expensive than using lemon juice.

Step #4- Strain the liquid from your worm castings:

Worm Castings
Photo: Worm Castings, Credit: Instagram @ moderngrowerco

Once the acidic substance has been added to the compost, that’s when you need to strain them. Pull out the worms and allow them to continue working on their natural purpose. After awhile they will stop burrowing and start crawling around on top of your compost in search for food. The compost will begin to stink, which is the worm castings being extracted with the liquid. You can then begin filling up a few beakers with the extracted worm juice and move on to the next step.

Step #5- Add an extractant:

To make sure that the liquid flow correctly through your juicer or blender, you will need something to extract it from its original source. For this purpose you can use a juice extractor, which works very well and is very easy to use. The process involves putting a small amount of liquid into a specialized container and then screwing on your juicing attachment. Once that is done, you may begin juicing until the container is full.

Step #6- Extract and bottle your worm juice:

Your worms should be quite exhausted by the time you reach this stage of the process. Fill your juicer or blender up with as much juice extractor as you can get into it and then turn it on or move on to step #7 if using a juicer. The liquid will flow through the worm juice and then into your container, where you will have to collect it. You can do that by using a funnel and then pour your fluid fertilizer into bottles for future use.

Step #7- Filter your liquid fertilizer:

If you are using a blender, then all you have to do is throw it together with some water and then mix well. You can also do this with a funnel if you prefer. The mixture will then be filtered through a piece of cotton cloth and finished off with a lot of water to make sure that it’s all clean, clear and ready for use. However, if you go by the juices extractor method, then place the extracted liquid in another separate container. Once the liquid has been filtered, you can begin adding your nutrients to it.

Step #8- Add your micro nutrients:

Now that you have a few bottles of homemade liquid worm castings fertilizer, you may begin adding some extra ingredients to it. This will speed up the growth process, as well as add a lot more of the necessary nutrients, such as micro nutrients, trace minerals and all kinds of other substances that plants need to live and grow. You can then dilute it in water or use it at full strength to make sure that all of your plants get the necessary amounts of nutrition on a consistent basis.

Step #9- Store your liquid fertilizer:

After you have added all of the nutrients, you can then begin storing your homemade fertilizer in bottles. If you intend to use them on a regular basis, then it is better to store it in glass bottles, so there are no chances of spills or leaks. However, for large batches of vermicompost that are stored for longer periods of time, plastic bottles would be better. Make sure that the storage area is under complete darkness and then place the bottles inside a cardboard box or styrofoam to protect them from light. You can also use a cooler if you want to keep it in an area with relatively low temperatures.

Step #10- Use your liquid fertilizer:

Now that you have managed to make a few bottles of liquid worm castings fertilizer, you can then start using it on your plants and watch them flourish! You can dilute it in some water and then use it to water your garden and also spray it onto your plants. Since the micro nutrients, trace minerals, acids and other substances that are added to the worm juice will help the plants grow faster. Use this homemade compound as a fertilizer rather than as a pesticide.

Photo: Composting, Credit: Instagram @ zerowastestore

How Do I Harvest And Store Liquid Fertilizer?


The liquid can be harvested from a worm farm after about one week. You may need to water the bedding or castings for two to three times before you see the liquid flowing out from the bottom of the bin. But keep in mind that excess watering may cause the water to pool at the bottom of your bin and make it difficult to drain out. You can easily drain out excess water by putting something like a smaller tray underneath your container or by using gravity-based separators like drain spouts or siphon tubes (available at garden supply stores).


The liquid can be stored in a sealed container for up to 4 weeks. This way, you can keep it in the refrigerator and use it to irrigate your plants during dry periods. You may also add it to the bedding in your bins to supply them with nutrients and improve the structure of the soil.

How Do I Use Vermicompost Liquid Fertilizer?

When used as a foliar spray, ½ gallon should be mixed with 5 to 6 gallons of water every week. When mixed with soil, 1/3 cup should be added for every gallon of soil. As a concentrated liquid fertilizer, it is best used on flowers and leaves that need more nutrients in their growth cycle, like leafy greens, flowers and root crops. You can spray it directly onto leaves or mix it into the soil or compost heap where plants will absorb it through their roots. Using Vermicompost Buttons. There are organic and plastic buttons available at most of your local garden supply stores that you can use as drip irrigation when applying liquid vermicompost to your plants. This is also a very useful method if you want to avoid the hassle of mixing it with water. Just soak the buttons in vermicompost liquid and place them underneath your plants to automatically irrigate them. You can also use this method for indoor plants or seedlings that don’t need too much water per day.

How Do I Use It For Fish And Poultry?

There are no special instructions for using vermicompost or worm castings as fish fertilizer, except that you should avoid using it along with other fish fertilizers, which may cause your fish to suffer from ammonia toxicity. Besides that, it is still a good idea to keep the water clean by removing the excess algae, which is a good source of food for fish. If you experience any issues with your fish in your aquarium, you may want to consider using a fish specific liquid fertilzer instead.

Poultry owners can use vermicompost, worm castings or compost tea in the drinking water of their chickens and other poultry animals to help prevent diseases and improve their growth. Before adding them to your poultry’s drinking water, you should mix them with water or put them inside a one-gallon container that you can hang inside the chicken pen. This will help the microorganisms multiply quickly so they can protect your chickens from disease-causing microbes. You can also add it to their feed if they do not drink enough water and are more susceptible to diseases.

Potential Drawbacks

As with all natural fertilizers, there are some limitations that you should know about. First, liquid worm castings can only be used on plants that require low amounts of nutrients. Also, it can burn your plants if it is applied too much or too often at once. Avoid applying it to your vegetable gardens and ornamentals during their flowering and fruiting stages, as this will reduce the fruit and flower production. For example, tomatoes are sensitive to high levels of nitrogen and may not produce well if they receive too much vermicompost fertilizer when they are flowering.

If excess vermicompost is applied to your plants, you should also apply more water to them, as this will dilute the concentration of nutrients and prevent burning. However, this can cause you to waste a lot of water, which may not be good if you do not have enough rain. If this happens, it is best to apply it only when it rains or after watering the plants with plain water. Superphosphate and molasses can be used in order to decrease the amount of watering needed.

Bottom Line

Liquid vermicompost is an excellent soil amendment that can be used as either a liquid fertilizer or an ingredient in a worm composting system. It may not be as effective as other fertilizers we commonly use, but it is much cheaper and easier to work with. It also has more beneficial microbes and helps plants get the nutrients they need when they are most actively growing. If you are looking for an all-natural way to improve your soil, this liquid fertilizer can help make a significant difference in your garden.