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Can You Burn Plants With Compost Tea?

Compost tea is something I keep hearing about and wanted to give it a go in my garden. I’ve heard fertilizer with high amounts of nitrogen can burn plants and I thought, “Could compost tea burn plants too?”. So, I decided to find out more.

Here’s what I found.

Compost tea can burn plants if the compost has high levels of nitrogen. However, if your compost tea is made from kitchen scraps and not strong fertilizer or manure, it is highly unlikely it will burn your plants.

Now that we have that answered, what about the other curious questions that still need answers? Well, let’s take a look.

Can compost tea kill plants?

Similarly to burning, compost tea will usually only kill plants if there’s a high level of nitrogen. It’s usually a better idea to brew your own compost tea from food scraps than it is from a store-bought fertilizer.

If a tea that’s strong in nitrogen is left on a plant, the leaves, roots, and stock can start to die. Some symptoms of this are if the plant is suddenly withering or turning yellow.

How do you make compost tea?

Compost tea can be made with or without aeration or brewing, and you don’t need to add supplements for the microbes, although it can lead to better results.

To make a quick version of compost tea, you’ll need:

  • 5-gallon bucket full of water
  • 1 to 4 handfuls of compost

If you’re more of a visual person, check out this video by MIgardener.

How do you use compost tea on plants?

There are two main ways to use compost tea on plants. One is applying directly to the soil, called root drenches, while the other is a leaf or foliar spray.

Once you have your compost tea brewed and ready, you can apply 5 to 10 gallons for every 0.25 acre when using for root drenches, and 5 gallons for every 2 acres for foliar sprays.

If you are using compost tea for a small number of plants, you can use a spray bottle, pump sprayer, or watering can to disperse the tea.

Should you dilute your compost tea?

If your compost tea is brewed from food scraps, and you’d like to dilute it to be safe, you can dilute it to a ratio of 1:4 or 1:10. That is, for every one cup of compost tea you can add between 4 to 10 cups of water.

However, as long as you’re not using manure or synthetic fertilizer, it’s unlikely you’ll need to dilute it much.

How often should compost tea be applied?

Compost tea can be applied every day if desired. Those made from manure or higher in nitrogen should only be applied no more than once a month and should be highly diluted.

Related questions:

Does compost tea really work?

There is some speculation that compost tea doesn’t really work. According to the Illinois College of Agricultural Science, the nutrients from compost tea can’t get absorbed through the leaves as well as previously thought. They suggest the better alternative is to use regular compost as a mulch and let the rain create the tea.

Should you pH your compost tea?

Depending on your water’s pH level, your compost tea might be acidic or alkaline. For best results, and to promote beneficial microbes, brew your tea at a neutral pH. To adjust the pH, start by testing your water.