Why You Shouldn’t Bother Adding Tea Leaves to Your Garden
The gardening world is full of old wives' tales full of purported methods to grow the biggest tomatoes or tallest sunflowers. One of those stories is that tea is beneficial for your garden because it creates nitrogen, and the tannic acid benefits the pH of the soil. In truth, while tea will compost in your garden just like any other organic matter and likely isn’t doing any harm, there’s no science to suggest that tea, itself, has any specific benefit to your yard, either. Absolutely everything you compost will produce nitrogen, and any acid will affect the pH of your soil (which isn’t always desirable). I consulted with many garden centers as well as Concentrates, a well-regarded farm supply known for their mineral and fertilizer supplement stock, as well as their considerable knowledge of organic farming. No one working there had ever practiced this or could figure out any particular way tea would benefit your yard.
Tea is just dried and processed plant matter
Growing herbs in your garden is probably one of the most rewarding crops, particularly perennial herbs. While many herbs, like chamomile and mint, can be used to make herbal tea on their own, real tea leaves come from a tea plant, camellia sinensis. While it’s unlikely your local nursery will sell it, you can order this flower online as a start and plant it in your garden. Once the plant flowers, you can harvest and dry the buds and make your own tea. No matter what you make your tea with, whether it be herbal or camellia, when you’re done drinking, what’s left is bound for the trash unless you compost it. If you’re making tea with what you grew yourself, you likely aren’t using tea bags, so you can just place the spent tea in your compost and go back to your life. It should compost just fine, and would count as a green part of your compost (which is made up of wet, nitrogen-rich matter balanced with dry, carbon-based matter).
If you buy tea, then you need to consider what the teabag is made of. While most teabags are compostable, some have polypropylene in them and those should not be composted. Remove any staples or string, unless you are sure it is 100% cotton string, and remove the paper tag in case it has any coating on it. If you’re concerned about the teabag, you can just empty it into your compost and toss the bag.
Consider where you put compost with tea in it
Your soil has a delicate pH. Most plants enjoy a neutral pH, and gardeners go to the trouble of measuring the soil’s pH to determine that its in the right range. Some plants benefit from slightly more acidic pH, but slightly is the key word there. Blueberries, azaleas and strawberries are examples of plants that benefit from that higher acidity. Any acid is going to make your soil more acidic, and real tea (not herbal) contains tannins, which produce tannic acid. Just like tea is a plant, tannic acid is produced by trees and other plants as they decay, too. It’s not that tannic acid is specifically bad, it’s that it’s not particularly beneficial, either. If you are adding it into the environment on purpose, you’ll want to ensure the soil pH isn’t becoming too acidic for what you’re trying to grow.
Compost made with tea should not be confused with “compost tea”
If you garden enough, you’ll hear the phrase “compost tea” and how good it is for your garden, but that phrase does not refer to actual tea. Rather, this is the drippings of your worms or compost, which can produce a highly nutritious water fertilizer for your garden. Many worm towers actually come with spigots to collect this brew for use, but you would never drink this.