Oak Tea for blueberries

My own hubris dictates the belief that I am the first person to have thought of this thus wanting to protect the intellectual property.

Just kidding. Rationality tells me a few things:

  1. All I am doing is replicating a natural process at a faster rate
  2. With all of the brilliant minds in gardening, I cannot be the first to have arrived at this thought
  3. If I had the desire to spend 20 seconds on google, my hubris would likely meet a quick demise

In nature, blueberries are commonly found in soils with granite parents or new soils ground by glaciers out of rock, thus related to the previous point. They are also found in areas that have a continuous flow of acidifying organic matter like the high-tannin oak leaves. I will be zeroing in here for my strategy.

When walking along a forest in spring, a pattern in the fallen leaves that persisted through winter becomes apparent: oak. The high levels of water soluble tannins found in the leaves wards off decomposition until precipitation leaches out most of the acid. This action is what provides the blueberries with their ideal habitat. Similarly, this is why many sources recommend mulching blueberries with oak leaves. A rebuttal is usually issued stating that composted oak leaves are pH neutral but fails to account for the acid leaching rainfall that is needed in order to compost the leaves. Where does that leached acid go?

Now I am confident you know where this post is going. In an effort to limit off farm inputs, I want to utilize the many oak trees on the farm to acidify water for irrigation. Luckily for the blueberries, my well water tested slightly acidic which is unlucky for my pipes that corrode as a result. Municipal sources always buffer water to an alkaline pH to slow down the corrosion of piping in the infrastructure so take this into account if you are watering pH sensitive plants with a municipal water supply.

Making Oak Tea

Here is my plan: collect ~20 gallons of oak leaves, fill the 4 five gallon buckets with water which will displace the air between leaves, let tea steep for a few days, replace one irrigation a week with the oak tea. Composting will be the final destination of the spent tea leaves


This would appear to be a more biological approach to acidifying the soils slowly over time. I’ll be sure to monitor the pH of the tea to make sure the idea has merit and if it does prove successful, the readings should ensure that I don’t burn the roots with tannic acid that hasn’t been diluted enough.

If this idea works, it will certainly be more biological than my current approach of elemental sulfur soil amendments, cottonseed meal fertilization and vinegar infused irrigation. I will expand on my full blueberry-acidifying-soils strategy tomorrow!


4 thoughts on “Oak Tea for blueberries

  1. Dan, with all the vineyards in VA, think about grabbing spent grapes and using them for their tannins to mix into the soil? Not sure it will be the same, but could be easier to get old grapes from vineyards that are just going to get tossed anyway and then mix them in with the soil…. Not sure it will work, but just an idea.



  2. Pingback: My strategy for acidifying soils | thegreenergrassfarm

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