Watering your plants is one of the essential steps required to help them grow properly and successfully.
Watering is a delicate balance; too little and you could be depriving your plants of the nutrients that they need to thrive. Too much and you could potentially drown the roots, causing root rot or killing them entirely.
Ultimately, the point of watering is to deliver the proper nutrients to your plants. But what if watering wasn’t the only way to achieve that delivery method? You may or may not have heard that tea can be used as a watering method for your plants.
As crazy as it sounds, there is some truth to the matter. This is because tea and tea leaves are comprised of organic matter. It is that organic matter that makes for highly nutritious additives for plants.
So, it kind of seems like a natural fit to use tea to water your flowers.
Nutritious Facts Behind Tea Leaves
The reason that watering with tea can be so beneficial is that tea leaves have a number of viable components within that are beneficial to plants. Most dried leaves will contain around 4.4% nitrogen, 0.25% potassium, and 0.24% phosphorus.
Compared to most of the liquid pot plant fertilizers out there, tea leaves have substantially more nitrogen within. The thing to keep in mind is that, while the nitrogen promotes a leafier growth, most of that nitrogen will likely be unavailable to the plants.
Tea leaves also have a large amount of tannic acid to them. When adding that tannic acid to our soil, it helps to increase the acidity of the soil by lowering the acidity. For some plants, more acidic soil is the way to grow (think ferns, for example).
Just keep in mind that some plants tend to prefer more alkaline soil, so this isn’t universally beneficial.
There are some people who claim that watering plants, such as the Maidenhair fern, with green tea can promote serious growth and plant health. When compared to tap water, the one using the tea will have more fronds to it, whereas the one with regular water tends to be a bit denser.
The point is that watering with tea has different impacts, not necessarily better ones.
Use Tea in Plants That Prefer Acidic Soil
The best use of tea as far as a watering source is to implement it with plants that prefer more acidic soil. Some indoor plants that take more acidic soil could benefit from the change in levels of tannic acid within the tea.
Some of the plants that tend to do better with a little more acidic soil include rubber plants, spider plants, ferns (not the Maidenhair), oxalis, begonias, philodendron, orchids, African violets, tomatoes, poinsettias, Easter lilies, and hydrangeas.
It also matters how you apply the tea to your plants. The first step is to brew a pot of tea using a tea bag or two. Let your brew sit out overnight to allow it to properly cool. It cannot be emphasized enough that you should never, ever apply boiling water to your plants.
If it doesn’t kill the plant outright, it will shock it and severely damage or stifle the growth of the plant. After allowing the tea to cool overnight, apply it to your plants the next day as if you were normally watering.
Another way that you can do it is to simply bury a tea bag into the soil itself. Just make sure that if you go with this method, choose a paper one so that it can properly decompose. Choosing a polyester tea bag won’t degrade and will simply sit under the ground.
Not only will you want to put a paper tea bag in the ground, but you should take the staple and the string out since they really aren’t adding any value to the soil. They shouldn’t do any damage to the soil but shouldn’t be included, either.
There are also a few things that you will want to watch out for when using this method. Most plants prefer to have a pH level that is neutral. If you are planting near those kinds of plants, increasing the acidity by adding a tea bag will only serve to harm those plants.
Boston Ivy and Cacti are two neutral plants that will not do well with increased acidity.
Adding Nutrients to the Soil
The great thing is that you can add fresh tea leaves and tea grounds to your soil. This is because they contain not only the tannic acid mentioned above, but certain nutrients that can create a more fertile environment for landscape and container plants as well as gardens.
Tea grounds are organic matter, and they will improve the soil quality and increase the overall nutrient level of the soil as they begin to break down and decompose. The reason this is good is that it increases the overall activity of beneficial microorganisms such as earthworms.
Adding tea grounds into your soil can also help to improve oxygenation levels, which create a stronger root system in which your plants can grow. Plants take in their nutrients and water through the root system, which ultimately creates a healthier, more vibrant plant.
Tea Grounds in Compost and Plants
If you plan on applying used tea grounds with the express intent of improving the plant’s growth, there are two methods to go with. Either mix your loose tea leaves right into the soil or spread them around over the top of the soil in much the same way as you would with mulch.
When you are using tea grounds that are still in the bag, take them out or add the bags into the drainage layer for any potted plants. For vegetable or edible garden plants, you will need to add tea grounds via an indirect source such as organic compost.
Adding tea grounds directly into the garden soil during their active growth periods can potentially disturb the pH balance of the soil or even impact the flavor of what you’re growing.
In most cases, though, adding tea grounds to an organic compost pile can make for a healthy addition since they promote the decomposition of bacteria.
Without the organic compost to act as the vehicle, tea grounds can be added to garden soil well before planting your winter or summer gardens. It really all depends on the type of plant you are caring for and the soil balance.
What’s in Tea?
It may perhaps help us if we take a step back and understand just what is in tea. When brewing a cup of one of our favorite types of teas, we tend to not even think about the certain complexities within.
The fact of the matter is that there are sometimes thousands of components within a tea and some have yet to even be discovered.
With organic tea brands, gardeners can achieve a more efficient, cleaner impact on the plants that they are fertilizing. Organic teas might still have certain complexities or chemical components to them that some regular teas have, but they tend to be fewer and further in between.
Some teas even have pesticides within them, some being higher than allowable limits. What does this mean for your plants?
Well, if you plan to fertilize them with certain teas, it can be far safer and healthier to go with an organic option. The more natural and organic the source, the better it is for the health and development of the plants.
It is also important to note the healthy components of the tea. The first of which is polyphenols. These are micronutrients that we tend to find in most plant-based foods. It also contains tannic acid, which can benefit soil in a variety of ways.
Tea also includes theanine. This is an amino acid that we generally find not only in tea leaves but in Bay Bolete mushrooms as well. The acidic properties of tea can be highly beneficial to plants that enjoy a higher acidity.
Perhaps the most well-known aspect of tea is in the level of antioxidants. This is a powerful protection agent that can limit damage to cells. The natural antioxidants include not only the aforementioned tannins and phenols, but also include lignans and flavonoids as well.
Finally, tea contains a number of different vitamins and minerals including vitamins C, D, and K, riboflavin, and the minerals iron, calcium, nickel, magnesium, fluoride, and zinc.
Caffeine in the Garden
Plenty of amateur gardeners will use coffee grounds that have been directly added into a compost pile or the garden itself. These grounds, which will gradually break down over time, can improve the overall quality of the soil.
Since they contain about 2% nitrogen, as they begin to break down, that nitrogen is then released into the soil. This makes it sound like the caffeine is an excellent idea when planting, but it is important to pay attention to the parts about breaking down.
Adding uncomposed coffee grounds to your garden can actually stunt plant growth. Be safe by adding them into a compost bin first so that the microorganisms within can safely break down. Fertilizing your plants directly with caffeine will have an impact on your plants but it may not be a positive one.
The caffeine can still have a strong benefit and not just in keeping us away. In coffee plants, there are enzymes that build the caffeine. These are members of N-methyltransferases and are found in all plants and can build a wide array of compounds.
When it comes to the caffeine, those N-methyltransferase genes are mutated. When coffee leaves drop, for instance, they can contaminate the soil with that caffeine. That can curtail germination of certain other plants, lessening the overall level of competition for the coffee plant.
Basically, this means that too much caffeine can have a serious negative impact on surrounding plant growth.
Caffeine is a chemical stimulant. Because of this, it actually increases the biological processes in plants as well as humans. That includes the ability to absorb water and nutrients from within the soil, as well as the ability to photosynthesize.
Not only that, but caffeine can increase the pH levels within the soil, increasing the acidity and proving to be toxic to certain types of plants that prefer neutral or alkaline soils.
Insect Repellent
So, while it is probably detrimental to the overall health of your plants to use caffeine, at least non-composted caffeine, there are other uses that can be beneficial for your plants.
While there are many beneficial microorganisms and insects for a variety of plants, having a pest problem can be a major issue for steady plant growth.
There have been scientific studies showing that caffeine can work as an effective slug and snail killer, for instance. Additionally, it has shown to kill milkweed bugs, hornworms, mosquito larvae, and butterfly larvae as well.
The use of caffeine on these insects interferes with their reproduction as well as their ability to consume food. Not only that, but it can result in distorted behavior due to the suppression of enzymes within the central nervous system of the insect.
Best of all, unlike commercial insecticides and pesticides, it is a naturally derived ingredient. Those pesticides and insecticides contain a number of toxic chemicals within that can be dangerous for human exposure.
What’s interesting is that high doses of caffeine can be toxic to a wide range of insects, the nectar that the coffee blossom produces also has trace amounts of caffeine within.
The insects feed on this nectar and get a little bit of a jolt from those small amounts of caffeine. That’s what helps them to remember the scent of those flowers. Not only that, it ensures that their pollinators will revisit and remember those plants, spreading the pollen by proxy.
On the flip side, insects that feed on coffee plants, and any other type of plant that has caffeine within, have developed these taste receptors. The receptors can help them to identify the plants that have caffeine within so that they can be avoided later on.
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.