Can you spray worm tea directly on plants?

By Priya Agarwal


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!