How Coffee Grounds and Kitchen Scraps Can Help Houseplants Thrive

Find out which kitchen scraps can actually benefit your indoor garden and which ones you should still compost first.

We all like to save a little money when we can, and if we can reduce waste at the same time, that's even better. Perhaps that's why the idea of using food prep leftovers on your houseplants is such an appealing one. Of course, composting is a great way to do this, but you may have come across advice for adding certain common kitchen waste items like banana peels directly to your indoor garden. Or maybe you've seen Grandma place eggshells or citrus peels around her peace lilies. While some of these may provide important nutrients and other benefits to houseplants, others may do more harm than good. Here's a look at a few food waste products you're likely to have in your kitchen and how to use them effectively on your plants.

mug of coffee next to houseplant
Thir A Sakdi Wiml Ratn, EyeEm/Getty Images

Coffee and Tea

Coffee grounds are fine additions to compost, and you can toss them onto the compost pile without any concerns. This goes for used tea leaves, too, and tea bags made of natural material and free of staples. Because decomposition needs to happen to release nutrients that plants can use, it is better to compost these items first rather than add them directly to your indoor garden. Otherwise, they will likely encourage mold growth in your plants' pots (yuck!), and if added in too thick a layer, they can hinder water absorption.

What about the last splash of Joe in your coffeepot or the cold dregs at the bottom of your cup? These liquids contain nutrients like nitrogen that plants need for healthy growth, but they should be used sparingly. There's such a thing as too much of a good thing for both people and plants! Before you pour, dilute it with the same amount of water and make sure to use only black coffee or tea. You might enjoy cream, sugar, and other additives, but your plants won't. Wait to water until your plants' soil is dry to the touch, and use your diluted leftovers only about once a week. Both brewed coffee and tea are slightly acidic and over time may change the soil chemistry in your pots too much. If you notice any yellowing on leaf tips, go back to just plain water.


Chicken eggshells are full of calcium, which plants need to develop a strong cellular structure. They also contain small amounts of iron, phosphorus, and magnesium, which are essential for healthy growth. However, eggshells can take years to decompose and release nutrients to plants, unless you grind them up very fine. The better way to provide some of these nutrients to your houseplants is to pour boiling water over the shells and allow them to steep for at least 24 hours. Then use the resulting infusion to water your houseplants. Some people like to use the crushed shells as a mulch on top of the potting soil to help hold in some moisture. If you want to try this, make sure to clean the shells very well in warm water first so they are free of any raw egg or membrane that might smell bad or attract mold.

Banana Peels

All sorts of anecdotal evidence suggests that banana peels are nature's miracle solution to about any plant problem, such as repelling aphids and removing dust from your houseplants. A few scientific studies have found that the peels can make an effective natural fertilizer, and numerous DIY recipes exist for feeding your plants with them. If you decide to experiment with the peels, realize that while they aren't likely to harm to your houseplants, pests such as fruit flies find them quite attractive.

Orange Peels

Citrus peels are one type of kitchen scrap not recommended for adding to a compost pile. Instead, you can use the peels from oranges and other citrus fruits to keep pets away from your houseplants—many cats and dogs avoid the scent. Cut the peel into pieces about one inch square and leave them on the surface of the soil to deter dogs and cats from snacking on your prized plants. Fresh peel seems to have the most effect, so feel free to add more whenever you enjoy citrus fruit and clean out the old, dried out pieces once in a while.

Cooking Water

When you cook vegetables or eggs in water, some nutrients are boiled off into it. Once this water cools to room temperature, you can use it on your houseplants so they can benefit from those nutrients. This is an especially frugal tactic in regions that may be experiencing drought conditions that makes water rationing necessary. If you want to make this a regular practice, wait to salt your food until after cooking because salty water could burn your plants.

Nut Shells

Hold onto those pistachio shells (and even peanut shells) instead of throwing them out. They can be used to help with soil drainage. After rinsing the shells to remove any added salt, line the bottom of your houseplant's pot with empty shells to help excess water drain away from the roots. If your concern is keeping a fussy plant moist, use the shells as a mulch layer on top of the soil to prevent quick drying.

By repurposing these kitchen scraps, you can save on fertilizer or other soil amendments. You're also choosing a more natural, eco-friendly way to care for your houseplants while reducing waste.

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