Are Coffee Grounds Good for Peace Lilies?


Peace lilies are one of the most versatile houseplants around, which might have you thinking about using more unconventional care tactics, like coffee grounds. You might’ve even heard coffee grounds are good for indoor plants, especially when used as fertilizer. But is that really true of peace lilies?

Are coffee grounds good for peace lilies? Yes, coffee grounds can be good for your peace lilies. Primarily as a fertilizer due to their high nutrient content. The grounds are acidic, too, lowering your soil’s pH. Coffee grounds in your potting soil can ward off indoor pets like cats & also help reverse leaf browning on peace lilies.

In this article, I’ll talk more about what’s in coffee grounds that makes them such a great choice for Peace lilies. If you want to know how much coffee to use or how often to use coffee grounds on your Peace lilies, you’ve come to the right place!

What’s in Coffee Grounds That Benefits the Peace Lily?

I’ve written a lot recently about the various types of homemade fertilizers and composts you can use for your houseplants. Going the homemade route is especially beneficial, in that you can ascertain your plant gets the exact ratio of nutrients it needs. Plus, I advocate for homemade because it can be cheaper than the store-bought stuff and it’s fun to make, too.

Coffee grounds have long been an acceptable choice to naturally augment houseplants, peace lilies included. If you’ve ever wondered why that is, allow me to explain.

Nutrients

Your old coffee grounds are a great source of nitrogen, a prime nutrient many houseplants require. Peace lilies in particular do best with a mix of nitrogen, phosphorous, and potassium. While sure, you could always use commercially-produced fertilizer, if you have the coffee grounds handy, why not try them instead? 

Organic Matter

Besides its nutrient content, coffee grounds also provide organic materials to your peace lily’s soil. Organic matter, mixed into the soil your peace lily is growing in, can greatly help by providing more aeration, boosting water retention, and improving drainage. 

Acidity 

If you regularly read this blog, you may recall several posts discussing pH changes in plant soil. Should you have missed those, I’ll elaborate now. Your houseplant’s soil can be either acidic or alkaline, also known as basic. 

It’s good to know the difference, as some houseplants can survive in more acidic soil while others will die. The same is true of soil with a higher alkalinity.

While coffee grounds can generally boost your peace lily’s acidity, not all grounds work. You must add the coffee grounds in unwashed, as their acidity is higher.

Also, make sure you toss the grounds into the soil right away rather than waiting several days (or weeks). The fresher they are, the more acidic.

Peace lilies prefer a soil with a pH of 5.8 to 6.5, which is considered acidic (as is anything under 7.0). Thus, coffee grounds suit your peace lily just fine.  

Microorganisms 

Did you know a few microorganisms such as earthworms are actually pretty good for your houseplant? It’s true!

They will eat the organic matter as it starts to decay. Even better, as the earthworms wriggle and travel through your peace lily’s soil, they aide in aeration.

You don’t necessarily have to go hunting in your yard for earthworms to plunk in your plant’s soil unless you really want to. A bit of compost that contains organic materials and leaf litter should be enough to bring the earthworms to your indoor garden.

Now, I’ve said this before; some indoor gardeners aren’t thrilled with the idea of live bugs in their home writhing around in the plant soil. If you’re in the same boat, that’s more than fine.

Of course, your peace lily can live without earthworms, and there are plenty of substitutes, but if you can stomach them, they really do help. Your plants will thank you! 

How Can You Use Coffee Grounds for Peace Lilies?

You now understand more about why peace lilies love coffee grounds so much. That makes you want to hold onto your coffee grounds and feed them to this flowering houseplant going forward.

Here are three fantastic ways you to use coffee grounds that will benefit your peace lilies. 

Use as a Fertilizer 

With all the cool perks of coffee grounds, these make the perfect natural fertilizer for your peace lily. This fertilizer has the nutrients your plant needs, it can keep the peace lily’s soil acidic enough, and the soil’s aeration and water drainage will prevent waterlogging that could kill your plant.

I do want to mention that, compared to some other fertilizers, coffee ground fertilizer is a much more slow-releasing option. That means it won’t infuse your peace lily with nutrients as soon as you add it to the soil, but more gradually.

While there are always variables to take into account, you should expect to see the benefits of using coffee grounds with your peace lily within two to four months.

Want to get started with our own fertilizer today? As you sip your coffee in the morning, hold onto the grounds. You can also buy coffee grounds at the store and put those in without having used them. 

Then, take a thin layer of the grounds and spread it onto the peace lily’s soil. When you tend to your houseplant and water it in the future, the fertilizer will seep deeper into the soil, benefiting your peace lily as it does so. 

Use to Keep Pets Away

Peace lilies are undeniably beautiful. While you may love to sit and admire yours, make sure your cats or dogs don’t get too close.

The peace lily, or Spathiphyllum, is toxic to both, cats and dogs.

In dogs, consuming the plant triggers an inflammatory reaction that can lead to upper airway, throat, tongue, and mouth swelling. Cats will have an upset stomach as well as mouth irritation. 

While moving the peace lily plant out of reach should prevent your dog from getting to it, cats can climb and jump. That makes it harder to prevent kitty from reaching your indoor garden. 

Luckily, coffee grounds atop the soil will stop your cat in its tracks. You might want to combine that effort with some mothballs so your cat really isn’t inclined to munch on your peace lily (or any of your other indoor plants!). 

Reverse Leaf Browning 

I did read on the forum Dave’s Garden, one poster lamented about how his peace lily’s usually bright green leaves were brown and yellow. Only the tips were affected, but still, this couldn’t be good, right? 

Further down the thread, one indoor gardening enthusiast mentions how he knows someone who would feed coffee grounds to the peace lily regularly. The poster mentioned how this person’s peace lily was in wonderful shape for doing so.

While coffee grounds may be able to reverse peace lily leaf browning and other discoloration, it depends on what’s causing it.

If you overwater your houseplant–a classic beginner & pro’s mistake–then the leaves may turn brown or yellow. The same is true of underwatering. 

To clear up any confusion, you should aim to water the peace lily weekly, getting the soil moist but not soaking. If you notice a bit of sagging from your plant, that’s it telling you it needs H2O. 

If your peace lily receives too much sunlight, leaf browning is typical. Using the wrong type of fertilizer is also problematic, as is fertilizer with a heavy concentration of nutrients.

Overdoing it on the fertilizer is another way to turn your peace lily’s leaf tips brown .

Coffee grounds can reverse the fertilizer-related issues, but not the ones caused by improper lighting and watering habits. It’s important then to identify what may cause your peace lily leaf browning before using coffee grounds as a cure-all. 

How Much Coffee Should You Add to Your Peace Lily?

You’ve saved up your coffee grounds for your peace lily, but you’re not sure if you have plenty or not enough. You’re also weary of hurting your houseplant by mistake.

After all, too little fertilizer could cause a nutrient deficiency while too much can damage the plant, which you’ll see in the leaves.

How much is appropriate to use then? If you get your day started with about a pot of coffee grounds for your morning brew, that should be a sufficient quantity to feed your peace lily.

You can add it all in at once or add it gradually but if this is your first time, I’d recommend starting slow and see your peace lily reacts. Then add more if all is well. 

How Often Should You Fertilize Your Peace Lily with Coffee Grounds?

The same way you have to keep a watchful eye on the quantity of coffee grounds you use as a peace lily fertilizer, how often you fertilize is also just as important.

Some indoor gardeners will add about one coffee pots worth of coffee grounds monthly and have the best results from that amount of time while others will do so more seldomly, such as every couple of months.

I know that’s a big difference in time, but that’s because every peace lily is going to have varying requirements at different times throughout its growing and dormant phases.

If you’re not sure which method you should start with, I’d recommend marking your calendar to see how your peace lily is looking every two months after applying the coffee grounds. At two month increments you’ll be able to reconsider your peace lilies needs & make an informed decision.

As winter arrives, you want to fertilize on a six-week basis. This will put your peace lily plant in the best position for a healthy, bountiful spring and summer, the plant’s natural growing season. 

Can You Use Other Natural Fertilizers for the Peace Lily? 

What if you’re not a coffee drinker? That doesn’t mean you’re relegated to store-bought fertilizers only. You can make the following fertilizers instead.

Vegetable Peel Fertilizer

This first green fertilizer uses peelings from both fruits and vegetables. As you eat healthily throughout a week, collect the skins and peels and then store them. 

When you have enough, put the ingredients in a food processor or blender to make the peels into a liquid. As you have an equal ratio of liquid fertilizer to water, you can pour this in your peace lily’s pot.

Other houseplants might appreciate this DIY liquid fertilizer as well.

Here’s a small caveat. Don’t hold onto your vegetable and fruit peels for too long, as fermentation could occur, making the scraps useless.

Even a week can be too long in some cases. Be sure to smell the peels and if you detect an alcohol odor, the peels have most likely already started to ferment and its best to avoid using those particular peels.

Using fermenting peels will cause you and your plant headaches and problems that your peace lily might not come back from, so don’t take a chance. It’s much easier to start saving new peels if you feel your peels could possibly be fermented.

Grass Clippings Fertilizer 

Grass clippings are a spectacular natural fertilizer because they contain phosphorus, potassium, and nitrogen, all of which a peace lily needs. Other green materials are acceptable for this fertilizer, too. 

Take your grass clipping and pour water into a bowl or container so the water is about in equal quantities to the amount of grass you have. Then, toss the grass in the water bowl and stir occasionally over three days. 

Strain the remains through a sievs and you have yet another handy liquid fertilizer. You should use this on a two-month basis, maybe as seldom as every three months. Each time you want to fertilize using grass clippings, you will have to remake your grass clippings fertilizer all over again, as this form of natural fertilizer only lasts for about two days, at the most. 

Fred Zimmer

I'm a lover of plants, animals, photography, & people, not necessarily in that order. Currently, I'm focused on photographing indoor plants & chachkies. I write & rewrite articles about creating an environment where indoor plants can thrive. I'm good at listening to music but bad at shopping to muzak.

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