We discuss the difference between worm leachate and worm tea, bringing you all the facts about each, and advising you on which one you should be using on your plants for the best results.

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Worm tea and worm leachate, what’s the difference? This is a common question that can be quite confusing to those who are just starting out on their worm farming journey. Whilst they are sometimes used interchangeably, they do in fact differ in both definition, and benefit for your plants.

There is a lot of conflicting information online and this article aims to explain things clearly, without getting too technical. Read on to learn just what each of these terms mean, and how you can use both to help your garden thrive!

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The difference between worm tea and worm leachate

So, what is worm tea and worm leachate, anyway? Worm tea is an organic, nutrient-rich liquid fertilizer that is made by soaking (or “steeping”) worm castings, commonly referred to as worm poo. Worm leachate on the other hand is purely the liquid that drains from your worm farm, often collecting in a tray at the base of the bin.

There are no additional steps needed to make worm leachate, whereas worm tea requires “brewing”, much like the regular tea we drink. So, in a way, worm tea is made from castings, while leachate is just produced by liquid flowing through your worm bin. That is the key difference between the two. 

Worm tea benefits

Studies have shown that worm tea accelerates plant growth and improves resilience to disease. This is because it contains loads of good bacteria to boost soil microbiology, which the plants then suck up through their roots.

It’s also a great source of nitrogen, which is an important element for strong and healthy plants. Whilst solid worm castings act as a slow release fertilizer, worm tea is more fast acting. It’s great for when you want to give your garden a rapid dose of nutrition for an added boost.

How to make worm tea for your plants

Making worm tea is actually really simple! All you need is a bucket, a porous cloth, a healthy amount of worm castings, some distilled water (non-chlorinated) and maybe some molasses if you have any, but it’s not essential. The purpose of the molasses is to help feed the bacteria during the steeping process. If you’re already worm farming, then sourcing the worm castings should be easy. Otherwise, you can purchase some from suppliers like Uncle Jim’s Worm Farm.

Step 1

The first thing to do is put your worm castings in a porous bag and tie it closed. Place the bag in a bucket (around 5 gallons) and fill it with non-chlorinated water. This can be either distilled water, or rainwater.

Step 2

Add a couple of table spoons of molasses (optional) to the bucket and let the castings steep overnight. If you want to accelerate the process, you can use an air pump, like what you would use in a fish tank, to help aerate the mixture to give it more oxygen. 

Step 3

Check your worm tea the next morning. It should be a light brownish color and smell pleasantly earthy. Remove the used castings and spread them on your garden and voila! You now have some high-quality, organic fertilizer to use on your plants.

How to use your worm tea

Worm tea is potent stuff. Before using it, dilute it with water in about a 1:1 ratio for the best results. Then feel free to apply it liberally all over your garden using either a spray bottle or watering can. That’s really all there is to it!

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How to use worm leachate on your plants safely

Worm bins contain both good and bad bacteria. For leachate to be able to be used on your plants safely, the good bacteria must outnumber the bad bacteria. Whilst worms do most of the heavy lifting when it comes to generating good bacteria and microbes, a bin that is too wet, acidic, or smelly may indicate the presence of more bad bacteria. In this case, it’s important to consider whether or not you will use leachate on your plants. 

If the worm bin is healthy, and not smelly, then using leachate should be fine. Simply dilute your worm leachate with water using around a 1:9 ratio of leachate to water. You can also use a bubbler from a fish tank or an air pump if you have one to improve the oxygen content and quality of the leachate.

Whilst using worm leachate from a healthy worm farm on your plants is okay, we recommend you avoid using it on edibles if possible. There shouldn’t really be any issues, however, there is always a risk that there may be some nasty bacteria in the mixture. This will be absorbed by your plants, ending up on your dinner plate. We’d rather be safe than sorry, so just stick to giving your leachate to ornamentals.

Are There Disadvantages of Using Worm Tea?

As you can see, worm tea is a lot more beneficial for your plants. There are, however, some disadvantages to worm tea as well. Worm tea is made with worm castings, but worm castings take a lot longer to make and collect. They are also more expensive than just regular compost if you choose to purchase them from a supplier. Worm leachate on the other hand is quicker and less costly to collect. Simply drain it from your worm bin, provided it’s healthy and doesn’t smell. 

Worm tea also does not keep for very long. In cold temps, it only lasts three around days. While in hot temps, it only lasts for 48 hours. However, considering its benefit as a liquid fertilizer, Worm tea is still preferable over worm leachate.

On your way to happy, healthy plants!

Learning about vermiculture and differentiating between these two liquids can be a handful at times. Hopefully this article was able to help you determine the difference between worm tea and worm leachate! Just remember, worm tea is something you make with worm castings, while worm leachate comes straight from your worm bin.

Also, keep in mind that worm tea will always be healthier for your plants. Try using both and see which one works better for you. In the meantime though, may your worms stay healthy and your plants stay thriving!

If you want to know more about how to set up a worm farm, check out our worm farming for beginners guide here. Happy worm farming!

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