Are coffee grounds good for plants?

Kimberly
by Kimberly

I'd like to know are coffee grounds good for plants? I have heard different claims regarding this question and seen conflicting information online about coffee grounds for plants. Does anyone here have experience feeding your plants coffee grounds? It would be nice to be able to use my coffee grounds for something productive instead of throwing them out, but I want to make sure that it will not harm my plants. I'm assuming that even if it is ok to feed some of my plants coffee grounds, it might not be a good idea for all plants. What plants like coffee grounds?

I have both indoor and outdoor plants. If I use coffee grounds in my home as natural fertilizer, will it cause a bad smell in the house?

  13 answers
  • Sal3170064 Sal3170064 on Nov 27, 2018

    Mine are put in a compost bin with vegetable cutting. Then we use when needed. There are worms in the bin breaking down the waste. Then we use this to put on the plants.

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    • Janis Janis on Nov 27, 2018

      We place several days of coffee grounds in a bowl, take them outside and pour them on the ground. One of my hydrangea bushes is right next to a sidewalk, which keeps the ground on that side alkaline and produces pink flowers. Other side of same plant has produced purple and blue flowers.

  • Rowgop (Pam) Rowgop (Pam) on Nov 27, 2018

    For instance, you can sprinkle fresh coffee grounds around acid-loving plants like azaleas, hydrangeas, blueberries, and lilies. Many vegetables like slightly acidic soil, but tomatoes typically don't respond well to the addition of coffee grounds.


    https://www.gardeningknowhow.com/composting/ingredients/coffee-grounds-gardening.htm

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    • Don Don on Nov 29, 2018

      I see from this post you have a good answer. It all depends on what you plants need; acid or alkaline. Cheap soil testers can be found at Home Depot. I recommend them. Check your soil, check what your plants require, and proceed accordingly. I do recommend that you begin a compost heap and turn it regularly. Coffee, egg shells, and discarded raw vegetable along with small twigs and lawn debris make a nice mix. Just don't throw all of your coffee grounds in there. I can't give you an educated mix of the ingredients of your compost pile, but sort of use your intuition. I do recommend that at 4 to 6 month intervals you add a shovel full of cow manure. Remember to keep turning this mess once a week. After about 1 year you will have some golden soil to pot plants in and till in to your garden.


  • Hi Kimberly - Here's a great 101-style article on getting started with composting and everything you ever need to know - includes info on coffee grounds. Also how we DIY'ed building our compost bin. My Stepson built it for a Boy Scout merit badge. Hope this all helps and happy composting! Hugs, Holly

    https://pinkfortitude.com/composting/

    https://pinkfortitude.com/compost-bin/

    • Kimberly Kimberly on Nov 27, 2018

      Thanks Holly! That Stepson is mighty talented - a chip off the old block!

      I don't compost but now you got me thinking...

  • 1401470 1401470 on Nov 27, 2018

    They're great for amending soil. Rinse used coffee grounds to neutralize pH of 6.5- this will keep them from raising acid levels of the soil. Leftover diluted coffee works well too.

  • Patricia Patricia on Nov 27, 2018

    Mine go into my compost as well

  • Julie Julie on Nov 27, 2018

    My grandmother had the greenest thumb in town. She would throw both coffee grounds(keeps away snails. slugs, aerates the soil)and egg shells (potassium and calcium also keeps creepy crawlies away from flowers, vegetables, and leaves.) into her garden beds.

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    • Julie Julie on Nov 27, 2018

      Maman was my personal Earth Angel and now my Heavenly angel. Thanks, Kimberly

  • Janis Janis on Nov 27, 2018

    I sprinkle used coffee grounds all over my hydrangea bed to change the soil to acidic. The change in acidity develops blue flowers on the plants, rather than pink. Process takes over a year here.


    • Kimberly Kimberly on Nov 27, 2018

      Janis, that is so cool! I have hydrangeas and I am going to try this right away! Are there any other plants that coffee grounds are good for?

  • Mintpatty Mintpatty on Nov 27, 2018

    I've had house plants that others seem to think like coffee (the liquid) because they've had enough or it's cold so they dump it in the plants. The plants don't seem to object BUT when you water them you don't know if they've been coffeed or not so when you water regularly they run over & the water is brown & will stain carpet or wood flooring if it doesn't have a waterproof finish. I do put coffee grounds on the ground around my roses & once a week I take the garden rake & work them into the soil. Roses seem to like it.

    Mint Patty


    • Kimberly Kimberly on Nov 27, 2018

      Patty you crack me up  !

      It's good to know that roses like coffee grounds. I'll be sure not to share any actual coffee with my indoor plants - at least in rooms that are carpeted or have wood flooring. Do you have a picture of your roses? I would love to see them.

  • Lynn Sorrell Lynn Sorrell on Nov 27, 2018

    I live in AZ and after they are dried throw them directly out in garden along with crunched up egg shells. Depends what type of soil you have whether you should compost or just throw them out. It really helps with clay based or hard compacted soils. If you can shred filters in your paper shredder use them too unbleached is even better.

    • Kimberly Kimberly on Nov 27, 2018

      Lynn, thank you for sharing. Are you sure the filters are bio degradable? I'm pretty sure the ones I use are not bleached (I wouldn't want bleach in my coffee, just cream).

      How can I determine if my soil is clay based or hard compacted?

  • Nancy Turner Nancy Turner on Nov 27, 2018

    Worms love the coffee grounds in the soil. Most coffee that has been used loses a lot of the acidity. For hydrangeas, if they are meant to be pink, they won't turn blue if you give it the increased acidity, better to use the fertilizer made for the colors to give it the proper amount it needs. Clay soil is usually a bit lighter in color than the soil and is like stiffer playdough when you squeeze it in your hand. If you use egg shells for critter control, crunch them up, but not too fine. If you want to use them to add calcium to your plants(really necessary for tomatoes) they need to be as fine as possible so they don't take forever to degrade and release the calcium. The coffee grounds will help keep the soil looser like sand will when put in the soil. Coffee grounds are like everything else, yes in moderation when putting it around plants, like any other thing, too much is not good.

  • Deb K Deb K on Nov 27, 2018

    Hi Kimberley, this link tells you the best uses for coffee grounds in the garden

    https://www.growveg.com/guides/a-common-sense-guide-to-using-coffee-grounds-in-the-garden/

  • Lynn Sorrell Lynn Sorrell on Nov 28, 2018

    I also use my old filters for inside pot liners when I'm starting plants,herbs,veggies,or cut them up & use in muffin tins as little soil holders then just plant them when seedlings are big enuf.The ones I use fall apart after a month. Clay based soil can be any color just depends where you live. There are even forest clays which are dk.brown to black.Soil/Clay color is determined by what minerals,plants etc. are in the area.Darker topsoil only means more organic matter in it.CLAY-When it's dry it will crack and when damp or wet if you squeeze it in the palm of your hand to compact it then push on dirt with finger it will stay compacted. The top soil above & the soil underneath will be 2 totally different soils.Clay can be in both usually more the deeper you go the more more clay. Good read on science of dirt https://blogs.egu.eu/divisions/sss/2014/03/30/soil-color-never-lies/ GREAT GARDENING WEB SITE https://www.gardeningknowhow.com/

  • YesClips YesClips on Jun 16, 2022

    Here it says you can you even against snails and cats

    https://everythingaboutgarden.com/2022/06/07/coffee-grounds/