Can coffee grounds be used as a fertilizer for houseplants? (2024)

Coffee grounds are a low-level source of nitrogen and a minor source of calcium and magnesium, so the grounds,especially when composted, can be an effective fertilizer for acidic outdoor plants. While coffee grounds can be applied directly to your garden, as a top dressing to nitrogen-loving plants, the nitrogen will be more available to plants after the grounds decompose in your compost pile. Although coffee is highly acidic, most of the acidity is removed during the brewing process and most coffee grounds have near neutral acidity (around 6.8pH).

Forindoor plants, however,direct application of the groundsis not recommended. The fine grind typically used for brewing causes the grounds to pack down tightly, decreasing aeration,and providing a medium for fungal growth and a buildup of soluble salts.

A word of caution:fruit flies are attracted to coffee grounds, especially in enclosed compost heaps, where moisture is high--yet another reason to avoid using coffee grounds directlyon indoor plants or composting with them indoors.

For tips on a variety of gardening topics, see ourPlant Information Guides.
- Courtesy of NYBG Plant Information Service

Can coffee grounds be used as a fertilizer for houseplants? (2024)

FAQs

Can coffee grounds be used as a fertilizer for houseplants? ›

You know that last bit of coffee that always seems to be left in the carafe? Don't just pour it down the drain — you can use it to fertilize your plants, both indoor and outdoor. Coffee grounds (and brewed coffee) are a source of nitrogen for plants, producing healthy green growth and strong stems.

How to use coffee grounds for indoor plants? ›

Another way to recycle leftover used coffee grounds is sprinkling them on top of your potting soil. If you plan to test out this method, do so sparingly. Avoid creating a thick layer. Used (and fresh) grounds can lock together and create a barrier to water penetration and air circulation.

Which houseplants do not like coffee grounds? ›

Coffee grounds are an excellent soil amendment medium for some potted greenery. They have a decent nitrogen content of 1-2 percent, which they release slowly into the potting soil. But, you can't use coffee grounds on potted plants, like rosemary, lavender and geraniums, as it makes the potting mix too acidic for them.

Can I just sprinkle coffee grounds on plants? ›

Though gardeners most often use grounds that have been brewed, fresh coffee grounds can also be used. Only composted coffee grounds should be mixed into the soil, as fresh grounds will have a higher acid and caffeine content which may burn plant roots. Make sure that grounds aren't too wet to discourage possible mold.

What are the disadvantages of coffee grounds as fertilizer? ›

Harm Good Bacteria

Though adding coffee grounds to plant soil might help prevent harmful bacteria, it could also harm beneficial bacteria. Without good bacteria, plants may be exposed to disease and pests.

Is it good to water houseplants with coffee? ›

It's okay to water plants with leftover coffee or to add coffee grounds to the compost pile but learning when and why to use coffee in the garden will protect your plants. Only use black, unflavored coffee with this method to offer plants a source of nitrogen which can fertilize certain indoor and outdoor plants.

How often should I put coffee grounds on plants? ›

You shouldn't sprinkle more than a thin layer around your plants, or else the coffee grounds can become impenetrable, preventing water from getting into the soil. If you evenly sprinkle coffee grounds around the plants once a week or so, the amount will likely be okay.

What plants are harmed by coffee grounds? ›

In most cases, the grounds are too acidic to be used directly on soil, even for acid-loving plants like blueberries, azaleas and hollies. Coffee grounds inhibit the growth of some plants, including geranium, asparagus fern, Chinese mustard and Italian ryegrass.

Will coffee grounds hurt potted plants? ›

Don't just pour it down the drain — you can use it to fertilize your plants, both indoor and outdoor. Coffee grounds (and brewed coffee) are a source of nitrogen for plants, producing healthy green growth and strong stems. Coffee also contains calcium and magnesium — both of which are beneficial to plant health.

Do coffee grounds in plants attract bugs? ›

The smell of coffee is repulsive to many bugs and will keep them away from treated areas. Coffee grounds can be used fresh or used, but unused coffee grounds are more effective at repelling pests. The smell of burnt coffee is also effective at repelling pests.

Do you put coffee grounds on top of soil? ›

Adding coffee grounds directly to the soil as a fertiliser can be a good option. Coffee grounds are rich in nutrients, especially nitrogen. They also have some amount of other nutrients like potassium and phosphorous. Overall, this means that adding coffee grounds to your garden can work fairly well as a fertiliser.

Are eggshells good for plants? ›

Eggshells can make for great composting material, but the water you boil your eggs in can also be useful in the garden. Eggshell water is a nutrient-rich drink for your plants and an inexpensive fertilizer option.

Are banana peels good for plants? ›

Banana peels can be placed directly onto pot plant soil, or around the base of your garden as mulch. As they decompose, they will release nutrients into the soil to feed plants. If using banana peels in your garden, place a single layer straight on top of the soil, being sure not to let them touch the plant stem.

Do pothos plants like coffee grounds? ›

It boosts energy, raises alertness, and is a great way to get some beneficial antioxidants in your diet! If you've ever wondered if you could share this magic potion with your Pothos plants (Epipremnum aureum), you can! Coffee has tons of incredible benefits that will make your Pothos thrive.

Why should coffee grounds not be used in the garden? ›

Excess coffee grounds, if applied to the soil before composting, have multiple effects on the soil system. In addition to microorganisms tying up nitrogen temporarily, the caffeine residues in the spent coffee grounds can suppress germination and slow the growth of some plants.

How do you use coffee grounds as potting mix? ›

Like any type of fertilizer, coffee grounds are only effective when used sparingly. It is never a good idea to add too much, as that could do more harm than good. The proper proportion is usually around 4 to 1, or twenty-five percent of coffee grounds to mineral soils by volume.

Is instant coffee grounds good for plants? ›

Coffee is a great fertilizer for plants.

Coffee contains some of the same nutrients that are good for us too, like nitrogen, potassium, calcium and magnesium. The nitrogen in coffee helps plants to produce greener, stronger and healthier stems. So reuse those grounds—not the actual cup of coffee sitting on your desk.

Do plants grow better with coffee grounds? ›

Are coffee grounds good for plants? Coffee grounds are an excellent compost ingredient and are fine to apply directly onto the soil around most garden plants if used with care and moderation. Coffee grounds contain nutrients that plants use for growth.

Do gnats like coffee grounds? ›

Coffee grind is great at removing gnat infestations. Dry the grind thoroughly – this will prevent mould from forming – and spread it over the potting soil. A thin layer will keep the female gnats from laying their eggs. Additionally, the coffee can fertilise your plants.

References

Top Articles
Latest Posts
Article information

Author: Tuan Roob DDS

Last Updated:

Views: 6538

Rating: 4.1 / 5 (62 voted)

Reviews: 85% of readers found this page helpful

Author information

Name: Tuan Roob DDS

Birthday: 1999-11-20

Address: Suite 592 642 Pfannerstill Island, South Keila, LA 74970-3076

Phone: +9617721773649

Job: Marketing Producer

Hobby: Skydiving, Flag Football, Knitting, Running, Lego building, Hunting, Juggling

Introduction: My name is Tuan Roob DDS, I am a friendly, good, energetic, faithful, fantastic, gentle, enchanting person who loves writing and wants to share my knowledge and understanding with you.