It Appears We May Have Finally Stumbled Across The Best Usefor Coffee Grounds In The Garden Weed Killer
Remember, caffeine inhibits plant growth. This study conducted by the International Plant Propagators Society noted that using coffee grounds did result in lower germination rates. White clover, Palmer amaranth, and perennial rye were the three plants used in their study.
Perhaps a liberal sprinkling of coffee grounds on peskyweeds is just what you need to give them the boot. Or try boiling them to makea concentrated weed-killing spray.
Im sure by now you are a little disheartened with the newsthat coffee isnt the best thing to give you a pest-free garden with a biggeryield. Maybe you are even nervously eyeing that pile of coffee grounds youdumped in the compost bin.
Sounds Like A Good Idea But Do Coffee Grounds Work
Sarah Hardgrove is a horticulturist from Melbourne, and her masters research focused on the effects of spent coffee grounds on garden plants.
“It’s often collected as a resource from coffee shops, and recommended to be put straight on the garden,” Sarah says.
“It sounds like a good idea; reduce the logistics of composting it first. We have so much of it, Melbourne is such a coffee drinking city.”
For her research, Sarah;set up an experiment to grow radishes, leeks, sunflowers, violas and broccoli across different soil types in both a glass house and outside.
The plants were subjected to differing amounts of spent coffee grounds in their soil, ranging from 2.5 to 20 per cent. The coffee grounds were incorporated in the top 10cm of soil. A control group was set up with no coffee;applied.
After around 10 weeks, the plants were harvested and weighed to compare growth.
Sarah says all plants in the research trial suffered from being grown with coffee grounds.
“Growth was inhibited in all soil types, nothing responded well. We saw pretty much the same trends across all treatments, substantially lower biomass in the plants,” she says.
“In one treatment with broccoli, the control plant grew to about four grams. Grown with coffee it weighed less than half a gram. They were so tiny it felt silly weighing them.”
So what caused this huge reduction in plant;growth?
“What we theorised is the toxic effects of the grounds and the caffeine,” Sarah says.;
The Soil Will Become Too Hard
Clayey soil is not ideal for philodendrons. But adding too many coffee grounds can make the soil clayey. This type of soil becomes very hard when it dries.;
This type of soil will hinder the growth of the philodendron as the philodendrons dont prefer soil that gets bone dry.
Therefore, you should add other organic matter to the coffee grounds to maintain a balance.
Read Also: How Much Caffeine In Snapple Diet Peach Tea
Not The Buzz You’re Looking For
To understand why caffeine is bad for your garden, you need to understand why certain plants produce caffeine in the first place. You probably know that both coffee and chocolate contain caffeine, even though they come from entirely different plants. Those plants aren’t even related they evolved the ability to produce caffeine independently, something biologists call “convergent evolution.” When two species evolve the same trait completely on their own, it’s a sign that the trait probably has a very useful purpose. For caffeine, that purpose is competition: It kills off any plants in the surrounding area.
While you might think you squeezed every last drop of caffeine out of those grounds in your french press, think again: A study in the Journal of Agricultural and Food Chemistry found that there can be up to 8 milligrams of caffeine per gram of used coffee grounds, depending on how long the grounds steep in the water. That means that after you brew a shot of espresso, the grounds still contain about as much caffeine as a cup of tea.
In an article for the Guardian where he did his own informal gardening experiment with coffee grounds, botanist James Wong concludes, “I love a quirky piece of hort advice, and some are repeated so often you assume they are true, but often they call them old wives’ tales for a reason.” Drink your coffee all you want , but keep those grounds away from your garden.
This article first appeared on Curiosity.com.
Add Coffee Grounds To Compost
Good compost contains a mixture of brown and green ingredients. Brown materials such as dried leaves, sawdust and newspaper bring carbon to the mix. Green materials such as tea leaves and grass clippings offer nitrogen and protein.
Compost is a great way to make use of something that would have ended up in landfill. Coffee grounds, paper filter included, fall into the green category which means they are rich in nitrogen at approximately 1.45%.
They also contain magnesium, potassium and other trace minerals.
See: Monty Don’s warning about compost heed his advice or risk attracting rats
You May Like: Diet Snapple Raspberry Tea Caffeine
Can Coffee Grounds Hurt A Pepper Plant
Now that we have gone over the many benefits of using coffee grounds in conjunction with your pepper plants, it is time to look at the possible negative side effects that they might have on your plants.
As mentioned earlier, coffee grounds contain acidity and are very high in nitrogen. Excessive acidity and nitrogen toxicity both have the potential to hurt or kill your pepper plant. For this reason, moderation is critical.
Another factor that must not be overlooked is the caffeine content of coffee grounds and caffeines effect on plants. The caffeine content will greatly differ depending on the type of coffee grounds used, their age, and other factors. Too much caffeine is capable of stunting your plants growth, and in some instances, can shock and kill it.
This is another reason why used grounds are highly preferred to new ones.
It Supports The Worm Population
According to many gardeners, worms actually love eating coffee grounds as food. Using coffee grounds in your garden can lead to an increase in the worm population of your soil, which is vital for the health of plant roots. Worms also aid in breaking down compost and offer several other benefits to gardens. Adding coffee grounds will keep the worms in your garden happywhich in turn leads to a happy gardener.
You May Like: Does Snapple Tea Have Caffeine
How To Apply Coffee Grounds As A Fig Plant Fertilizer
If you have a handful of coffee grounds, you can apply it directly onto your plants soil. But if you have a daily pot of coffee, generally more than 1 cup, consider composting it first to decrease the caffeine. Usually, it takes about 2-3 months for the coffee grounds to decompose and become usable by the plant.
Depending on how many coffee grounds you have, and what you prefer, there are a few ways you can use coffee grounds as a fig plant fertilizer:
- Apply it directly
- Mix it with mulch
- Compost it
Generally, you can apply a small and infrequent amount of coffee grounds directly to the top of the plants soil .
However, if you have more than the suggested amounts of coffee grounds above, consider either mixing them with mulch or composting them before applying them to your fig plants.
For example, some good mulches to use for fig plants are straw, bark, and leaves. Simply mix the mulch and coffee grounds together and apply in a 1-3 inch layer over the soil .
Aside from providing a slow release of nutrients, the mulch will also help the soil retain water and protect it from the sun. Remember to keep the mulch at least 3 inches from the plants trunk to avoid any mold from spreading.
What Kills Slugs In A Garden
Oh, and while were on the bug train, another common question has to do with slugs. If coffee is as good at killing things as the studies state, then what does it do to our arch nemesis, the slug? We hate to be the bearer of bad news but theres not much information in the way of this, and its not confirmed whether coffee repels or even kills slugs. Suppose theres only one way to find out but remember, do not put the coffee grounds close to your plants .;
Don’t Miss: Is There Caffeine In Snapple
Are Coffee Grounds Good For Tomato Plants
Tomatoes and coffee, they do seem to have a good thing to do together. Growing them together can be both fun and exciting.
You get to harvest fresh fruit from your tomatoes each year, then you also get to add some interesting flavors to those fresh fruits. One of the great things about growing these two together is that they make a great combination with ground coffee.
What exactly is coffee ground? Coffee grounds are basically mineral-rich coffee left after brewing a pot of coffee. You probably just know it by another name: gourmet coffee.
Coffee grounds add a lot of flavor and body to coffee. They are used mostly in gourmet coffee shops to bring out the richness of the bean.
Do they work well in growing tomatoes? Gourmet coffee grounds have lots of antioxidants, which can help tomatoes thrive.
The more antioxidants per pound of tomato, the better. This is one reason why whole-wheat coffee beans are often mixed with tomato pulp to make up for the lack of antioxidant-richness in most grocery store-ground beans.
Can you grow ground coffee in your garden? Yes, you can! They dont need an intense amount of sun to thrive. Tomatoes will grow just fine in small amounts of sunlight provided the ground is well-drained.
Are coffee grounds good for tomato plants? You bet they are! Just remember though, that ground coffee isnt the only thing you need to keep your tomatoes healthy. Water, sunlight, and nutrients are also essential for growing healthy tomatoes.
The Benefits Of Gardening With Coffee Grounds
Treehugger / Alexandra Cristina Nakamura
Coffee is one of the most highly traded commodities in the world and research into its effects on human health is abundant and ongoing. While less abundant, research on coffee’s effect on plant growth continues to evolve. Search the internet for plants coffee grounds and you’ll find hundreds of gardening websites promoting the use of coffee grounds, praising their nitrogen-rich quality and ability to help plants photosynthesize. Perhaps you’ve already read that grounds also help the soil retain water, repel slugs and snails, and improve the structure of the soil, and that they are especially beneficial for acid-loving plants.
Some of this is indeed true and comes from reputable sources that have conducted their own independent research. Coffee grounds have been shown to improve water flow and soil structure. Used by itself, finely ground coffee is easily compacted, and can act as a barrier to moisture and air movement, but when coffee grounds are mixed with a variety of other types of organic material, they improve water retention and air circulation. Peer-reviewed research conducted at Washington State University recommends that coffee grounds constitute no more than 20% of total compost volume.
Recommended Reading: A&w Root Beer Have Caffeine
It Can Make The Soil Acidic
Philodendrons prefer the soil to be slightly acidic, but if the acidity increases, the plant will not tolerate it. The ideal pH level requirement of philodendron is between 5.0 and 6.0.
If the soil your philodendron is planted in is already acidic, adding coffee grounds in any form will increase the acidity that will burn the plants roots.
Also read: What Type Of Soil Does A Philodendron Need?
Peppers Love Coffee Grounds
We are a no-food-in-the-trash household. Not even coffee grounds. I save coffee grounds year round to use in the garden. Theyre a great soil amendment. Coffee grounds add organic matter to the soil and provide food for earthworms and the rest of the micro herd. Did you know that peppers love coffee grounds?
For more tips on growing peppers, follow the link.
Peppers like nitrogen and coffee grounds are full of it. You can mix the grounds into the soil or spread them on top. If you have a lot of grounds you can use it as a mulch. I dont like it quite that much so I place two or three cups of grounds at the base of each plant before watering. The water will disperse the grounds and take nitrogen down to the roots.
Providing enough nitrogen ensures adequate leaf growth, and that protects the peppers from sun scald. Pepper plants branch out like trees. Dont go absolutely nuts with the grounds or youll have too many leaves and not enough peppers. If youre getting more new shoots and not enough peppers, stop adding grounds. One or two applications in a growing season should be plenty unless your soil is severely nitrogen deficient.
Read Also: Is There Caffeine In Snapple
Are Coffee Grounds Good Or Bad For Plants
Coffee grounds ascribe a controversial topic when determining whether they are good or bad for plants.
It is, therefore, necessary to determine the correct prerequisites such as the type of plants and the type of soil that best thrive on the use of coffee grounds;
Relatedly, coffee grounds can be bad or good for plants depending on how you use them. So, are coffee grounds good for plants? Yes, coffee grounds can be very beneficial to plants when used in moderate amounts as mulch and fertilizer.
They contain a considerable amount of vital nutrients such as nitrogen and potassium, which promote plant growth.
What Coffee Grounds Do
If you tune into the grounds-for-gardens channel, youll learn that people count on used coffee grounds to do all kinds of things. Spread on planting beds like mulch, grounds are said to repel cats, fertilize soil, kill slugs and keep weeds at bay. A coffee mulch is also rumored to beckon earthworms and acidify soil. Other gardeners work coffee grounds into beds, swearing it aerates and acidifies soil.
You May Like: Does The Caramel Ribbon Crunch Frappuccino Have Caffeine
How Do Coffee Grounds Help Strawberry Plants
Coffee grounds contain a good amount of nitrogen, phosphorus, magnesium, and copper, all of which are important to maintain a healthy plant. They also increase the acidity of the soil, which is helpful for strawberry plants as they prefer more acidic soil with a pH of 5.4-6.5.
Like most plants, strawberry plants require three main nutrients: nitrogen, phosphorus, and potassium . Coffee grounds already contain two of these primary nutrients, making them a suitable fertilizer for strawberries .
Secondary nutrients are also important but arent needed in the same quantity.
Some of the secondary, or trace;nutrients;found in coffee grounds include:
Also similar to most fruiting plants, strawberry plants prefer slightly acidic soil with a pH of 5.4-6.5. This is good news because coffee grounds also have an acidic pH, but the level of acidity depends on if youre using fresh or used coffee grounds.
Fresh coffee grounds have a pH of 5.5-6.8, while used coffee grounds have a pH closer to;6.8. This is because when brewed, the coffee grounds lose a lot of the acid and caffeine through the water.
Either way, you can see that the pH of both fresh and used coffee grounds closely matches the soil pH that strawberry plants like. This means that you wont need to worry about making the soil too acidic by adding too many coffee grounds.
Still, if youd like to be safe, you can always measure your strawberry plants soil pH every month or so.
S To Using Coffee Grounds In Your Garden
Applying;used coffee grounds;to;your garden;as fertilizer for your plants is a simple process:
- ;After you’re done making coffee in the morning, allow the coffee grounds to cool to room temperature.;
- Sprinkle them in a light layer at the base of your;acid-loving plants.;
- You can work them into the top layer of the soil using your hands, or using a small garden trowel.;
- Then, you can cover the coffee grounds with a light layer of;mulch;to ensure that they stay moist. If coffee grounds dry out, they can repel water, so they must be covered with;organic material.
- Remember, it’s ok to troubleshoot, whether you’re using coffee grounds as a;pesticide;or solely as fertilizer. Trying coffee on different types of plants, changing up the;caffeine content;by using decaffeinated coffee grounds, or switching up the number of coffee grounds you use in the soil can all make a difference.;
In addition to creating a more acidic environment for your;acid-loving plants;to thrive, adding coffee grounds to the soil also:;
- Improves the;soil structure, helping the roots to take a keep a stronghold in the ground
- Works as a;repellent;for many pests, including slugs and snails
- May inhibit the growth of weeds around the plant’s base
Add Used Coffee Grounds For Plants And Your Compost Pile
Mixing or adding coffee grounds in soil is a good way to build the soil structure. The perfect place to start is to add coffee filters and coffee grounds directly with grass clippings to the worm bin or compost pile.
Why are coffee grounds good for plants?;Coffee is a good source of nitrogen and you can include it to the plants nutrition thru compost coffee grounds.
Adding used coffee grounds;to compost puts nitrogen fertilizer into your compost soil.
However, it is also important to keep in mind the acidity of coffee grounds. Balance this out with yard scraps, kitchen food scraps, and a good source of calcium carbonate like wood ashes or lime to balance out the pH and also add more phosphorous.
Keep in mind that the fungus growing on coffee tends to use up a lot of nitrogen. Again, its a good idea to have a good mixture of organic matter and other materials in your compost pile or compost heap.