Any harm with coffee grounds in soil?

[FallbrookCA]

I've seen some threads in here regarding some people adding coffee grounds to soil or mulch, but is there any harm to it? I mainly ask cause I had a couple of palms get frizzle top, which I have treated and are better now, I'm just worried that I may do something wrong to those two palms and want to avoid that since I just got them over the initial problem. Thanks everyone 

[Jimhardy]

I have mixed straight coffee into the

soil and it didn't seem to bother anything...

you may want to make sure your palm likes

a more acidic soil if you use a lot.

[Matt in OC]

Nope, no harm at all that I've seen.

[Palmaceae]

I use coffee grounds all the time, seems to control scale also!

[Cindy Adair]

I am saving my coffee grounds but so far have yet to try using them.

[rprimbs]

Yes, if the coffee grounds are not well composted they can actually be harmful to plants -- especially in pots.  The California Rare Fruit Growers ran several stories about it.  They are probably safer for use in the ground but I would keep them away a little ways away from the stem of the plant.

Of course you probably remember the brilliant  discussion on composting.  You need to mix nitrogen (greens) with "carbon" (The brown stuff).  And a very cheap source of 'nitrogen' is um.. urine.  I've never tried it but apparently some people here tried 'storing' it in the house (bathroom?) -- and it can really get to stink.

[mnorell]

Not only is coffee great for your body (see a summation from Harvard here), it is wonderful for your garden soil. Aside from the many untested compounds in the coffee bean, it is an excellent soil acidifier and a slow-release fertilizer as well. Here is a Sunset Magazine article showing a basic chemical analysis of Starbucks coffee grounds (which you can generally have from your local store for free just by asking). There is also good anecdotal evidence (e.g., Tom Broome's findings) about its insecticidal properties towards certain critters such as the crawling life-stage of scale. I use it constantly and it really does make your soil rich, crumbly and full of earthworms, grubs and everything else in the web of life...just about perfection, at least to my own tastes in what makes for a good garden soil. I'm growing plants on an island composed of solid oolitic limestone, with whatever municipal and garden mulch I can compost, plus coffee grounds and every other bit of vegetable waste from the kitchen. It works!

[FallbrookCA]

  On 12/21/2016 at 12:26 AM, mnorell said:

Not only is coffee great for your body (see a summation from Harvard here), it is wonderful for your garden soil. Aside from the many untested compounds in the coffee bean, it is an excellent soil acidifier and a slow-release fertilizer as well. Here is a Sunset Magazine article showing a basic chemical analysis of Starbucks coffee grounds (which you can generally have from your local store for free just by asking). There is also good anecdotal evidence (e.g., Tom Broome's findings) about its insecticidal properties towards certain critters such as the crawling life-stage of scale. I use it constantly and it really does make your soil rich, crumbly and full of earthworms, grubs and everything else in the web of life...just about perfection, at least to my own tastes in what makes for a good garden soil. I'm growing plants on an island composed of solid oolitic limestone, with whatever municipal and garden mulch I can compost, plus coffee grounds and every other bit of vegetable waste from the kitchen. It works!

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Yeah I basically have an unlimited source with my work so I figured I'd capitalize on it,  just wanted to ensure it wouldn't cause some kind of negative reaction.  Thanks for all the feedback.

[Danilopez89]

I use my old coffee grounds in my garden all the time. When I first started adding it to my soil I began to notice a lot more earthworms crawling around. Especially near the areas where I would dump my coffee grounds. 

I did use it in some pots... I'll never do that again.

[_Keith]

Coffee grounds are not all that acidic and are close to pH neutral between 6.5 and 6.8 so unless you have a palm that likes very alkaline soils I would not worry about that part.  The earthworms are an extra plus and a good sign, imho.

[Jimhardy]

I have sprinkled it on the soil and mixed

it in as well as sprinkling on the top of the

soil of potted plants,never had a problem.

[FallbrookCA]

  On 12/21/2016 at 12:26 AM, mnorell said:

  On 12/21/2016 at 2:00 AM, Danilopez89 said:

I use my old coffee grounds in my garden all the time. When I first started adding it to my soil I began to notice a lot more earthworms crawling around. Especially near the areas where I would dump my coffee grounds. 

I did use it in some pots... I'll never do that again.

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Why would you not use it in pots? What happened to those? 

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[Josh-O]

  On 12/21/2016 at 5:10 AM, FallbrookCA said:

 

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Coffee sprouted? 

[Neil C]

I'd also be interested to hear of any negative results when adding it to pots. I've heard it's good for deterring root mealy bugs.

 

Regards Neil

[Gonzer]

All my plants prefer the subtle bouquet of French Roast grounds freshly turned into the soil. For a worm-magnet clump on top of the soil they prefer Restaurant Blend grounds.

[Phoenikakias]

  On 12/21/2016 at 11:17 AM, Neil C said:

I'd also be interested to hear of any negative results when adding it to pots. I've heard it's good for deterring root mealy bugs.

 

Regards Neil

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I have the suspicion that application as top soil on several potted specimens has proven detrimental. This includes Dypsis jurassic in liners, Lanonia dasyantha in round pot, a sesitive Trachy with partial basal rot which hangs on for several years, Microcoelon wedellianum in tall cut plastic bottles,  a Dypsis plumosa in 1.4.lt liner pot and a tripple calamus in a bigger pot. The Trachy spear pulled, the Lanonia nearly spear pulled (arial part of new spear damped off but fresh tissue from below pops up), all dyspis jurassic were worsening until removal of the layer, the plumosa yellowed up and the calamus as well and finally three Microcoelon carked and another fourth struggles to survive. On the other hand potted Chamaerops loved it, but in last case did not help significantly, if at all, against scales; as long as scales are being exploited and promoted by ants, ground coffee has very little effect.

Edited December 21, 2016 by Phoenikakias

[Palm Tree Jim]

I have been using coffee grounds on and off for many years in the garden with no negative effects.

[Phoenikakias]

I have discovered on the other hand that coffee ground as top layer in potted palms gets cemented when dry, and it dries uo quickly, and in moist enviroment, like inside a cold frame, gets also mold.

Edited December 21, 2016 by Phoenikakias

[Pando]

The key is to mix coffee grounds into the soil, as amendment. Just sprinkling it to the top eventually creates a hard crust, as Phoenikakias mentioned above, which affects soil aeration, drainage and water retention. This fact limits its use in pots as it can be detrimental to the health of the plant for physical reasons, not chemical.

[Danilopez89]

  On 12/21/2016 at 3:54 PM, Phoenikakias said:

I have discovered on the other hand that coffee ground as top layer in potted palms gets cemented when dry, and it dries uo quickly, and in moist enviroment, like inside a cold frame, gets also mold.

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Same experience here.  And potted plant soil turned to muck. 

[Funkthulhu]

All of my potted plants seem to be benefitting of some living ecology from being outside in summers past.  Some of my larger pots even have some earthworms in them, and all of them have some mycology going on.  Based on that, I've never had a crust form from coffee grounds, they get incorporated pretty quickly whether I do it myself or let nature take its course.  All of my plants, palms and not alike, seem to get a bit of a boost from a hit out of the old french press.  

Of course, Your Mileage May Vary...

[Danilopez89]

  On 12/21/2016 at 11:17 AM, Neil C said:

I'd also be interested to hear of any negative results when adding it to pots. I've heard it's good for deterring root mealy bugs.

 

Regards Neil

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I would suggest to spread coffee grounds near or around your pots. Or you can just mix your used coffee grounds with a couple gallons of water and give your palms coffee water.

[Tomw]

Coffee ground have worked wonders in my garden. For two years I was getting 40 – 50 lbs. of coffee each day Monday thru Friday. I have mixed it in the soils and as a top dressing that eventually gets mulched over. I have heard that the coffee grinds and also as a liquid helps with scale, but I have yet to see objective evidence of this and i believe that it’s not true. With having around 220 lbs. per week to work with and being an engineer geek I have tried every combination of coffee grounds with my cycads that have issues with scale with no success. I have tried potting mixes with high percentage of coffee grounds mixed it, as a top dressing, even piled it so high that the codex was almost buried and I have tried mixing it in buckets with water and us only that to water the plant with scale I have also used a mixture in a spray bottle to spray on the plant, and still have not seen a discernable decline in scale.

 

What I have found is that the coffee grounds work great for scale if you mix the coffee grounds in a bucket of water and add in Merit imidacloprid.      

[Gonzer]

Dumping grounds as a mound on the soil surface acts as a magnet for earthworms. After a few weeks you can then incorporate it into the soil.

[Ben in Norcal]

  On 12/21/2016 at 7:03 PM, Tomw said:

Coffee ground have worked wonders in my garden. For two years I was getting 40 – 50 lbs. of coffee each day Monday thru Friday. I have mixed it in the soils and as a top dressing that eventually gets mulched over. I have heard that the coffee grinds and also as a liquid helps with scale, but I have yet to see objective evidence of this and i believe that it’s not true. With having around 220 lbs. per week to work with and being an engineer geek I have tried every combination of coffee grounds with my cycads that have issues with scale with no success. I have tried potting mixes with high percentage of coffee grounds mixed it, as a top dressing, even piled it so high that the codex was almost buried and I have tried mixing it in buckets with water and us only that to water the plant with scale I have also used a mixture in a spray bottle to spray on the plant, and still have not seen a discernable decline in scale.

 

 

 

What I have found is that the coffee grounds work great for scale if you mix the coffee grounds in a bucket of water and add in Merit imidacloprid.      

 

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Where on earth did you get access to coffee in those amounts?  I'd love that.

[FallbrookCA]

  On 12/22/2016 at 2:00 AM, Ben in Norcal said:

Where on earth did you get access to coffee in those amounts?  I'd love that.

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I have the same amount or more available per day haha. Wish your name was Ben in Socal, I'd let you have as much as you need

[DoomsDave]

In California

Our soil is alkaline, so coffee grounds acidify it, to benefit.

I don't drink that Witches' Brew, so I don't have grounds to toss.

But still.

I concur with chemical and physical comments and verdicts above.

 

[Danilopez89]

  On 12/21/2016 at 10:33 PM, Gonzer said:

Dumping grounds as a mound on the soil surface acts as a magnet for earthworms. After a few weeks you can then incorporate it into the soil.

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Ditto. Coffee mounds are the best. Especially when you keep those mounds a bit moist. Worm magnet for sure!

Coffee mounds + chicken manure 

Edited December 22, 2016 by Danilopez89
Thank me later

[Tomw]

  On 12/22/2016 at 2:00 AM, Ben in Norcal said:

Where on earth did you get access to coffee in those amounts?  I'd love that.

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If you go to the local Starbucks and talk to the manager they will save their coffee grounds for you. This requires a real commitment to pick them up when you say you will. I never wanted them to save 40 to 50 lbs. and the they have to “drag” the bag to the garbage (not everyone can lift that). Your acid loving plants will be happy, happy, happy!!

[PalmatierMeg]

Coffee grounds add nutrients and repel pests. My two Cycas revolutas are developing scale so I plan to spread used grounds and water with diluted coffee.

[Patrick]

This thread has been very infomative, I learned a while back from the internet (It must be true), picked up and am going to spread out a bunch of grounds to try to stop my MEALY BUG problem on my Jubaeopsis caffra. I hope it helps.....

 

I guess the youngsters are in the soil and climb up to feed once they mature.

Edited December 31, 2016 by Patrick
I always think of something after the fact