What is Worm Tea?

What is Worm Tea?

by Teresa Frith

What is worm tea?

If you are a gardener, you want the best for your plants so they are healthy and vigorous. And that means using some sort of fertilizer to help the plants to grow big and strong.

A great way to do that is by using worm tea!

Don’t worry, it’s not as strange as it sounds!

So what is worm tea?

Well it isn’t actually tea like someone would drink, instead it’s a liquid made from worm castings, which is another name for worm excrement.

This worm tea can be made own you own if you have a worm farm, or you can get it at some gardening supply stores.

making worm tea

When asking what is worm tea, the answer is it’s made by soaking worm castings in non-chlorinated water in which you’ve also placed some molasses or brown sugar for the beneficial microbes to feed on.

You also need to aerate the mixture via an aquarium pump and some air stones to help oxygenate the worm tea.

This mixture needs to aerate for between eight hours and overnight to produce the worm tea. The result will be a brownish colored liquid.

Let it set for another day or two, then use it on your plants within four hours, or it won’t be good anymore.

This worm tea is used to fertilize all kinds of plants to include food plants or flowers as well as indoor or outdoor plants.

The worm tea is sprayed or poured onto the plants.

It is best to dilute the worm tea with water by putting it into a sprayer hooked to a garden hose, then watering your plants with the hose.

There are many benefits to using worm tea.

One of these it is actually will help keep some kinds of insects and pests from destroying the plants.

It is also non-toxic, so you can use it around pets or children. Worm tea is also eco-friendly as it doesn’t place dangerous chemicals into the soil.

Therefore, you can feel good about using it to fertilize your garden. It is merely a mix of beneficial bacteria, fungi, and other organisms which help to make the soil richer and better for plants of all kinds.

Don't Confuse Leachate with Worm Tea

using worm tea

One thing to note is when asking what is worm tea, is that some think it is the liquid that drains from a vermicomposting bin, but that is actually called leachate.

This liquid isn’t good for the plants as it tends to contain bad microbes instead of beneficial organisms. Some people say you can dilute the leachate at 10:1 strength (10 parts water, 1 part leachate) and use it on plants that you're not going to eat such as flowers or shrubbery.

Worm tea works because it provides these beneficial organisms which help put nitrogen back into your dirt, and the plants then absorb this vital nutrient. Since it’s in liquid form, the plants can absorb it much faster than powdered or solid fertilizers, so they receive an instantaneous energy boost.

So, if someone asks you “what is worm tea” now you can smile and explain it’s one of the best things a gardener can have to make their plants thrive via putting nutrients back into the soil they require to grow healthy and strong.

Can You Spray Worm Tea Directly on Plants?

 Worm tea is excellent liquid fertilizer prepared from worm castings, or vermicompost. One of the questions we’re often asked if you can use the worm castings from your worm bin to create a foliar spray. Well, the answer is yes. Worm tea can be used as a foliar spray. Let’s talk in detail about what a foliar spray is, how it’s used, the benefits it offers, and more.

What is a foliar spray? 

A foliar spray is something that is sprayed directly on leaves (or foliage), usually for pest control and/or plant growth. Some common examples of foliar sprays include neem oil, compost tea, kelp, fish emulsion, herbal tea, etc.

A foliar spray is generally less concentrated than solid fertilizer that’s placed on the soil. Different organic materials can be combined together to create a stronger solution that attacks multiple issues at once. For example, a neem oil, peppermint oil and worm tea spray will help battle fungal diseases in tomato plants while encouraging growth.

How is it used?


Preparing a worm tea spray is easy. First of all, you’ll need to harvest some vermicompost from your worm bin. Here’s a quick guide on how to do that.

Soak some worm castings in water overnight, strain the castings and use them in the morning. Now, take the nutrient-rich liquid that you have, and mix it with water in a sprayer. You don’t need to worry too much about the concentration – worm tea is a gentle herbal fertilizer, and you can usually eyeball it so you have enough to spray all the plants you want to. However, as a general guide, try to dilute it till it’s the color of dark tea. 

Your worm tea is now ready to be used as a foliar spray.

Spraying the worm tea is as easy as using your sprayer, but there are some best practices that you can use to maximize efficiency. For starters, spray in the morning, when it isn’t too hot or sunny. Avoid spraying right before rainfall or bad weather. Make sure to coat the undersides of leaves, because the stomata will be open, and the spray will hit them directly, helping strengthen cell walls, and increase resistance to aphids and white fly.

What are the benefits of spraying worm tea on plants?

There are many benefits of spraying worm tea onto your plants instead of using it to water your plants with. Here are some of them:

  • Worm tea, when sprayed directly onto plants, will help them produce more foliage and larger stems. This is ideal for plants that are grown for their foliage or stems.
  • This can provide an excellent boost to plants that don’t receive enough direct sunlight
  • Worm tea can also help deter aphids and white fly when sprayed onto leaves
worm tea

You should use worm tea soon after it has been prepared, and you can use it to water or spray your plants every two weeks. However, if you have enough vermicompost, you could use it as often as once a week – especially on fruiting or flowering plants. If you still have more left, you can consider giving some away, or selling it!