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Left over coffee..on plants

Posted by susancarol 7 (My Page) on
Thu, May 10, 07 at 9:54

In the past, I would have had a fit if someone poured coffee on one of my plants but let me tell you..there's a green rubber tree in our office that for the past couple of months have been dosing with coffee and it has become a remarkable looking plant--very healthy with a lot of growth so there must be something to this coffee thing. I think it especially likes Starbucks. :-)


Follow-Up Postings:

RE: Left over coffee..on plants

Hey Susan,

Normally I'd agree w/ how you used to feel, but thru this winter & since, I've been giving leftover black coffee to my Xmas cactus, rather than buying acid-loving fertilizer for just this one plant. It normally blooms for New Years & this year, it had a 2nd blooming abt 10 wks later, more blooms than ever before! I too was just amazed, it's the only thing I've changed in its care/culture.

Hum ... maybe I should try same for my Ficus elastica, thx for the tip!

RE: Left over coffee..on plants

My plants love coffee, I also use the grounds in my potting soil, used tea also. My husband drinks about a pot and a half a day, I save the grounds. Starbucks gives grounds away for composting.

Just be careful not to use coffe with creamer or too much sugar, this can cause an imbalance in the soil, encoursge mold and ants.

RE: Left over coffee..on plants

I had a Sansevieria (One of the slim green leafed varieties.) that survived for 13 years on nothing but leftover black coffee.

RE: Left over coffee..on plants

Albert, what happened after 13 years with your plant? Just wondering if the coffee diet finally killed it.

RE: Left over coffee..on plants

Coffee is a mild fertilizer. It has natural tannic acid, which is much safer than any fertilizer synthetically made. It wouldn't have killed the plant.

RE: Left over coffee..on plants

After 13 years I got the velvet boot. I took my plant and went home. Gave it light, fertilizer and water and it put out a half dozen offshoots. Then I got a job out on the North Slope in Alaska and it had to go. It was in a pot worth perhaps twenty bucks and I sold it for $31 at a yard sale after agreeing to toss in a dozen smaller plants too. It was a rare beauty. Someone got a bargin.

RE: Left over coffee..on plants

The only coffee I drink on occassion is the powdered type? French Vanilla..Does anyone know if this type will work on plants? Thanks, Toni

RE: Left over coffee..on plants

Check the ingredients on the French Vanilla but my guess would be that you'll have too many extras.

I get a lot of coffee grounds from Starbucks and use for the lawn (just sprinkle the grounds over) and my compost pile. Ironically, I can't stand the way the stuff tastes!

RE: Left over coffee..on plants

LOL GreenJen, you buy coffee from Starbucks for your grass? LOL..
Forget the powdered coffee..I read the ingredients and there IS too much stuff..creamer, corn syrup and other stuff..oh well..
I love the smell of coffee and grounds, but don't like its taste..I drink tea though..wonder if tea grounds would be as effective as coffee grounds..Toni

RE: Left over coffee..on plants

Check your starbucks, they give their used grounds away for composting. We get two gallon bags of the stuff.

RE: Left over coffee..on plants

Well I have decided to start giving my left over coffee to my plants that like the acidity.....I have heard about thisfor years so it must work for some plants. So far my list of plants that like the acidic soil are as follows....please correct me if I am wrong.

*Aloe Vera
*Christmas Cactus

RE: Left over coffee..on plants

Mentha, my dh would shoot me if I started buying coffee grounds for my plants..LOL.
Guess I'll have to stick w/vinager and acidic foods, but thanks anyway..Toni

RE: Left over coffee..on plants

The grounds should be free. If it isn't find another starbucks. They are big on composting, and give newspapers and grounds to anyone who ask just for composting. If you don't like starbucks have a friend pick up the grounds for you :) Or just buy instant, and yse tea grounds have the same effect as long as it's green or black, not flavored.

RE: Left over coffee..on plants

The grounds that are given away from Starbucks are used, and they'd much rather give it away for composting than throw it away. Just one Starbucks store on just one day will have enough used grounds for all your plants probably! But what Mentha is trying to say is that the grounds are completely free. Just tell them you'd like some used grounds for composting.
Hope that helps,

RE: Left over coffee..on plants

I love, love, love this forum. This is so informative.

Ok, so I have two nearby Starbucks, so I'm sure I can pick up the used grounds.

Now, what are the guidelines? Once I get the grounds from Starbucks, exactly how should I use them and for how long? If I use them, should I then avoid any other types of fertilizers for those plants? Can this be used year round?

Another thought...

Hey I just thought of something...

Some of us could bring the left over coffee grounds home from work. Like Toni, I use flavored coffee, but I certainly empty the coffee basket often enough to have access to grounds. Since I seem to be one of the few people who bothers brewing the coffee that EVERYONE drinks. The coffee at my job is in those filter pouches. Toni, maybe you could talk your husband into putting those into a ziplock bag and bringing them home.

Another thing...

If the coffee grounds are mixed into the plant soil, will there be mold?

RE: Left over coffee..on plants


I just mix the grounds into my potting soil when I'm mixing in more perlite and (sometimes) vermiculite, depending upong what I'm mixing for.

I buy the cheap 2 CF potting soil for $4 at K-Mart, then I buy a 3.5 CF bag of perlite at Orchard Supply Hardware for $14, and $18 for vermiculite for 3.5 CF also at OSH.

I've found the cheap potting soil does not have enough drainage for anything, but especially epiphyllums and jungle cactus, so I mix 1 2cf bag of potting soil to the same amount of perlite then add as much used coffee grounds as possible. Mix it all well. I store this mix covered in a plastic water trough, the heat from outside also works as a compst heap where it heats up and sterillizes the mix.

If I'm doing seedlings or cuttings, I add 1/3 of the above mix to one third vermiculite an 1/3 perlite.

If I'm doing houseplants, I add 2/3 potting soil to 1/3 perlite with a handful of coffee grounds/pot.

You can also use the grounds as a top dressing, if you have a good draining soil the grounds will sink into the mix.

As long as the grounds dry and are not flavored they will not mold, but if you allow it to clump, you could have a problem. I have a bucket sitting by my sink which I dump my husbands grounds in whenever I make him a new cup. The cool thing is you do not need to compost it, you can add it directly to your potting soil, or whatever. Do not add used coffee to this mix, because you want it dry, it's best to add the (cold not hot or warm) coffee directly to your plants.

If you want to add grounds to your compost, you can also add your veggie clippings to the bucket, but it should make it to the compost heap at least every other day. You can also add shredded newspaper to your compost. I tried tearing it up, but shredded works much better.

RE: Left over coffee..on plants

  • Posted by amany MI / 6 (My Page) on
    Tue, May 15, 07 at 10:54

Thanks Mentha!

Since I last posted, I scored three used filter pouches. lol They are ziplocked and in the refrigerator. I'm sure I'll get quite a few more before the day ends.

I was thinking that maybe I could just go ahead and rebrew them when I get home. Perhaps I'll double up since they've been used. I don't think anyone at work has heebeejeebees or cooties, so it should be ok. Just in case though I'll wash out my coffee maker thoroughly afterwards. ;-)

Thanks again.

RE: Left over coffee..on plants

What does shredded newspaper do?
I keep newspaper to line birds cages, and when I repot plants inside the house, so there's no lack of paper here.
I think there's a Starbucks in the next town..I'm sort of embarrassed asking for their grounds..LOL..don't know how they'll react..Most ppl in this area haven't the faintest idea about caring for house plants..
Most ppl buy common annuals and are satified..Toni

RE: Left over coffee..on plants

I BELIEVE that mentha is referring to using the shredded newspaper (and veggie scraps) for composting, not for the making of a suitable potting medium.

RE: Left over coffee..on plants

Al is right, I meant add the newspaper (not colored ads) to your compost. Not directly to your plants. Most people just throw out or recycle newspapers and don't realize they make excellent and cheap additions to your compost.

RE: Left over coffee..on plants

LOL! a lot of my plants are enjoying a big healthy sip of coffee right now also. everybody is very green and happy. and my rubber plant is THRIVING at the moment also. It's one of my most beautiful plants. keep it up. i have also buried a few tea bags in plants around the house, with the same outcome.

RE: Left over coffee..on plants

I finally decided how to use those pouches last night. I decided to just let them sit in a gallon of room temp water for about 4 hours. (I couldn't bring myself to plop them in my coffee maker.) Then I poured the liquid into a gallon jug and will keep it refrigerated. I'm going to use it on my diefs, peperomias, arrowhead, aloe, Christmas cactus and rubber tree a couple of times a month for some. Every other month for others.

I came across another discussion on the forum by doing a search. It's about fertilizing acid-loving plants. There is a link provided by Karen715 that gives a partial listing of what plants like acidic soil.

Here is a link that might be useful: Acidic Plants

And another one...

Here's a post with an even longer list of acidic soil loving plants.

Here is a link that might be useful: A longer list

RE: Left over coffee..on plants

So, to ask a question on an old topic, are there any plants that do rather badly with a more acidic soil? Who should we keep our coffee grounds away from?

RE: Left over coffee..on plants

This is copied from amany's earlier link, this is the desired pH of many houseplants. Neutral pH is 7.0, lower numbers are acid. As you can see almost every single one will tolerate slightly acidic soil and the vast majority prefer it.

For example, this list says Hibiscus prefer 6.0-8.0, meaning they like neutral but will tolerate slight acidity. I dump coffee on my hibiscus and they don't complain.

Abutilon 5.5-6.5
Acorus 5.0-6.5
Aechmea 5.0-5.5
African Violet 6.0-7.0
Aglaonema 5.0-6.0
Amarylis 5.5-6.5
Anthurium 5.0-6.0
Aphelandra 5.0-6.0
Araucaria 5.0-6.0
Asparagus Fern 6.0-8.0
Aspidistra 4.0-5.5
Azalea 4.5-6.0
Baby�s Breath 6.0-7.5
Baby�s Tears 5.0-6.0
Begonia 5.5-7.0
Bird of Paradise 6.0-6.5
Bishop�s Cap 5.0-6.0
Black-eyed Susan 5.5-7.5
Blood Leaf 5.5-6.5
Bottlebrush 6.0-7.5
Bougainvillea 5.5-7.5
Boxwood 6.0-7.5
Bromeliads 5.0-7.5
Butterfly Flower 6.0-7.5
Cacti 4.5-6.0
Calcaolaria 6.0-7.0
Caladium 5.0-6.0
Calla Lily 6.0-7.0
Camelia 4.5-5.5
Campanula 5.5-6.5
Capsicum 5.0-6.5
Cardinal Flower 5.0-6.0
Castor Oil Plant 5.5-6.5
Century Plant 5.0-6.5
Chinese Evergreen 5.0-6.0
Chinese Primrose 6.0-7.5
Christmas Cactus 5.0-6.5
Cineraria 5.5-7.0
Clerodendrum 5.0-6.0
Clivia 5.5-6.5
Cockscomb 6.0-7.0
Coffee Plant 5.0-6.0
Coleus 6.0-7.0
Columnea 4.5-5.5
Coral Berry 5.5-7.5
Crassula 5.0-6.0
Creeping Fig 5.0-6.0
Croton 5.0-6.0
Crown of Thorns 6.0-7.5
Cuphea 6.0-7.5
Cyclamen 6.0-7.0
Cyperus 5.0-7.5
Dieffenbachia 5.0-6.0
Dipladenia 6.0-7.5
Dizgotheca 6.0-7.5
Dracaena 5.0-6.0
Easter Lily 6.0-7.0
Elephant�s Ear 5.0-6.0
Episcia 6.0-7.0
Euonymous 6.0-8.0
Bird�s Nest 5.0-5.5
Boston 5.5-6.5
Button 6.0-8.0
Christmas 6.0-7.5
Cloak 6.0-7.5
Feather 5.5-6.5
Hart�s Tongue 7.0-8.0
Holly 4.5-6.0
Maidenhair 6.0-8.0
Rabbits Foot 6.0-7.5
Spleenwort 6.0-7.5
Fig 5.0-6.0
Fittonia 5.5-6.5
Freesia 6.0-7.5
Gardenia 5.0-6.0
Genista 6.5-7.5
Geranium 6.0-8.0
Gloxinia 5.5-6.5
Grape Ivy 5.0-6.5
Grape Hyacinth 6.0-7.5
Grevillea 5.5-6.5
Gynura 5.5-6.5
Hedera 6.0-8.0
Heliotropium 5.0-6.0
Hens and Chickens 7.0-7.0
Herringbone Plant 6.0-8.0
Hibiscus Plant 6.0-8.0
Hoya 5.0-6.5
Impatiens 5.5-6.5
Ivy Tree 6.0-7.0
Jacaranda 6.0-7.5
Japanese Sedge 6.0-8.0
Jasminum 5.5-7.0
Jerusalem Cherry 5.5-6.5
Jessamone 5.0-6.0
Kalanchoe 6.0-7.5
Kangaroo Thorn 6.0-8.0
Kangaroo Vine 5.0-6.5
Lantana 5.5-7.0
Laurus (Bay Tree) 5.0-6.0
Lemon Plant 6.0-7.5
Mimosa 5.0-7.0
Mind Your Own Bus. 5.0-5.5
Monstera 5.0-6.0
Myrtle 6.0-8.0
Never Never Plant 5.0-6.0
Nicodemia 6.0-8.0
Norfolk Island Pine 5.0-6.0
Oleander 6.0-7.5
Oplismenus 5.0-6.0
Orchid 4.5-5.5
Oxalis 6.0-8.0
Palms 6.0-7.5
Pandanus 5.0-6.0
Peacock Plant 5.0-6.0
Pellionia 5.0-6.0
Peperomia 5.0-6.0
Philodendron 5.0-6.0
Pilea 6.0-8.0
Plumbago 5.5-6.5
Podacarpus 5.0-6.5
Pointsettia 6.0-7.5
Polyscias 6.0-7.5
Pothos 5.0-6.0
Prayer Plant 5.0-6.0
Punica 5.5-6.5
Sanserieria 4.5-7.0
Saxifraga 6.0-8.0
Scindapsus 5.0-6.0
Shrimp Plant 6.0-7.0
Spanish Bayonet 6.0-7.5
Spider Plant 6.0-7.5
Succulents 5.0-6.5
Synogonium 5.0-6.0
Tolmiea 5.0-6.0
Tradescantia 5.0-6.0
Umbrella Tree 5.0-7.5
Venus Flytrap 4.0-5.0
Weeping Fig 5.0-6.0
Yucca 6.0-7.5
Zebrina 5.0-6.0

RE: Left over coffee..on plants

My sister grows the most wonderful orchids that are always reblooming. She liked to rub it in because I always wind up killing mine. She would buy me new ones and remind me to give them coffee, which DW and I would do. Yet they would continue to die. One day she was looking at at a sad surviving plant and asked me why I had coffee grounds in the pot. "Because you told me to." It seems the grounds in an orchid mix will rot the roots. I was suppossed to put liquid coffee, not grounds, in the pot. Lesson learned.

RE: Left over coffee..on plants

As a caffeine addict and constant gardener, I usually drink coffee while watering my plants (group therapy). Anyway, the grounds after each morning brew go right outside into one of the hydrangeas, roses, clematis, and any plant I feel needs a boost. I brag to all of our neighbors that our local soil is moderately alkaline 7.5 or more. My soil, after years of coffee grounds and tea bags, compost, and old bananas, is around 6.8-7.0!

I would shy away from putting the grounds in orchids as well since orchids for the most part like a free-draining compost and the coffee grounds might clog the "pores" between the pieces of bark. Besides, orchids are a little different than most plants, and the persistant acidic grounds might be a little too overwhelming for some sensitive orchids. The leftover coffee (diluted) would be fine. I would never pour pure anything into my orchids, other than water. But for other houseplants, pour away!!

RE: Left over coffee..on plants

I love the coffee idea, but how often? amany said "a couple times a month for some", but many of the earlier posts (susancarol and pirate_girl) implied that it was a much more frequqent occurrance, to feed the plant any leftover coffee.

And I realize it will vary by plant. More often for acid lovers, the general idea anyway?


RE: Left over coffee..on plants

  • Posted by jodik 5 Central IL (My Page) on
    Tue, Aug 26, 08 at 11:35

My husband has severe ADD... rather than becoming a Riddalin zombie, he keeps a steady supply of sweetened coffee coursing through his bloodstream! Needless to say, we have coffee grounds coming out of our ears! We actually own and use a 2 burner Bunn coffee maker, and it's active 24 hours a day. I should think about buying stock in Folger's!

After reading this thread, I now know what to do with all those grounds that I normally dump in the trash! With any luck, the lawn and gardens will look a little better next year!

Thanks for sharing all this caffeinated information!

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