Tea and plants

So I heard this crazy idea that people would brew tea and use it to water their plants. Initially I thought this was ridiculous until I saw some enthusiasts displaying their amazing tea-watered plants.

So it there some proof to tea watering?

What if my plant like Earl Grey but doesn’t like Green Tea?!

You know I like to make sure everything is scientifically sound before proposing any advice, so what does tea do to your soil?

It’s worth pointing out that tea and tea leaves are obviously natural organic matter, generally most organic matter makes great nutrients for plants. So I’m already starting to think there is some potential here.

Dried tea leaves contain about 4.4% nitrogen, 0.24% phosphorus and 0.25% potassium. There is significantly more nitrogen in tea leaves than in most liquid pot plant fertilisers. However, while nitrogen promotes leafy growth, it is unlikely that much of the nitrogen in tea is actually available to plants.

Tea leaves contain a high amount of tannic acid. When tannic acid is added to soil is lowers the soils Ph increasing acidity. Some plants do much better with slightly acidic soil. Ferns being a prime example.  However maidenhair ferns are the opposite, they prefer slightly alkaline soil.

Some people claim that watering their Maiden Hair fern with green tea works miracles. Someone online did an experiment with two Maidenhair ferns (see below). The one on the left was watered with Tea water, the one on the right was watered with tap water. The left one has got slightly more fronds (but looks a bit stringy), the one on the right has also got a bit denser. I’m not sure the results are conclusive.

Maiden Hair fern pic2

Before watering

MaidenHair FernAfter watering

Most scientific articles say you will get the better benefit if you just use a regular fertiliser every few weeks instead of brewed tea. However, there may be some benefit in increasing the soil acidity, here are some indoor plants that like slightly acidic soil.

Plants that like acidic soil:

  • Ferns (excluding Maiden Hair fern)
  • Rubber Plant
  • Spider Plant
  • Oxalis
  • Philodendron
  • Begonias (some varieties)
  • African violets
  • Orchids (some varieties)
  • Easter lily
  • Poinsettia
  • Tomatoes
  • Hydrangeas

So if you want to give the tea watering a try, here is how to prepare your tea.

How to apply Tea:

  1. Brew yourself a pot of tea with 1 or 2 tea bags
  2. Let it sit overnight so that it cools (Do not pour boiling water onto your plans…that’s just mean! and the temperature will shock your plant)
  3. The next day water your plants with the tea

Another way is to bury a used tea bag in the soil. Just make sure the tea bag is one of those paper ones that can decompose (not the polyester tea bags). Also, remove the staple and string from the Tea bag as those don’t add any value.

Some things to watch out for. A lot of plants prefer neutral PH soil. Adding tea and increasing the acidity will actually do more harm.

Some plants that don’t like acidic soil

  1. Cacti
  2. Boston Ivy

Check out this for a list of the Ph’s preferred by different plants: https://www.gardenexpress.com.au/soil-ph-guide/

Happy Growing.