Hi!

I have heard over and over that digging in old coffee grounds is a great way to give plants a jumpstart. I drink a ton of coffee, but I have yet to figure out a way to dry out the coffee grounds that works for me. And so every time I empty out a pot of grounds, I feel guilty. Won't someone think of the plants?!

Does anybody have any favorite ways of drying out old coffee grounds or otherwise preserving them to use with plants? I read recently that you can do the drying in the oven, and that could work for me. But I'm curious to hear your practical advice.

Caffeinated,
Kathy

We get lots of coffee grounds from a local cafe. I don't bother drying them, they get used as a thin top dressing all over the garden (thick layers can form a water repellent mat if they dry out).

As a fellow coffee addict, i have a ton of coffee grounds each day. What I've done is turned my empty coffee cans into temporary "kitchen scrap yards". I put my egg shells, banana peels and all my coffee grounds into it. I even cut up the toilet paper rolls and throw them in there. When it's full, i put it into my compost pile outside, although I've thought about getting rid of that unsightly thing and just digging all those scraps right into my garden like my grandmother used to do.

Don't you need to dry them so they don't mold, though? I couldn't use them immediately, for instance. I'd need to stockpile them for spring...

I don't really do compost otherwise. With my schedule, it just wouldn't get tended to.

Well, i empty it once a week and reuse it a couple times after rinsing it out. I don't get all that much mold really. Any moldthat may grow is at the bottom and covered by new coffee every day until it's emptied.
Though, this method sounds like it's not for you.

If storage it's crucial, then you'll definitely need to dry them. There is the obvious drying methods like baking and dehydrator, but for simplicity sake, i would try just spreading it out on a cookie sheet in the morning and letting it dry all day. Then store it before bed and start over the next day. Your house will smell like a coffee shop, but that sounds like my kind of heaven .

Freshly used coffee grounds are clean and sterile, so they should be ok for a day or two on the counter.

You can dump the coffee grounds onto your frozen garden soil all winter. No need to hold or dry them.

mine go straight into the compost as "green" matter or some in the vermicompost bins.

I add mine to my compost pile.

Let the earth worms deal with them...they love coffee grounds.
In goes grounds on one end out goes fertilizer on the other.
Nature's way.
What more could you ask for?

Another coffee fiend... my standard practice is to put them in the compost pile, they are high N and probably the big driver of my compost.
Meanwhile I did also consider other ways of using them. Mine are in a paper filter, so I found I could set those to dry by standing them up in one of those plastic trays that mushrooms come in. This seemed to work pretty well, but I ran out of real estate in a few days, and before I was satisfied that they were dry enough to put in a coffee can for later... it was too big a hassle for me.
I tried using them as a de-icer instead of salt on the driveway one winter. Not terribly impressed with the results, although they do make temporary traction before sinking to the bottom of puddles, it was pretty nasty to track in on your boots.
Last year I dug some into my container soils, which seemed not to bother anything. I may try that again this winter.
If you mixed the coffee grounds into some potting soil (which is moist anyway but aerated) I don't think you would get any mold.
The bigger thought in my mind, how much would really be toooo much to mix into your potting mix. IDK. Maybe the sky's the limit.
Maybe we need to experiment?
If you have an unused half pot of soil kicking around, why not dig the grounds into that. If it did turn out to be too much N or too acidic for the plants in a 50-50 mix, you could always use it to sprinkle on or dig into your beds when spring comes.
I have a lot of eggshells as well, so I would probably try to combine the two.

There have been studies looking into using coffee grounds as part of a potting mix, I'll see if I can find the links. From what I recall, 5% coffee was fine but 10% and higher was detrimental. Last year I used 10% with potatoes in containers and they did very well, but then again potatoes don't really seem to care what they grow in.

Add me to the list of people that simply tosses them out on the pile of stuff that the chickens don't get.
I'm much too busy to ever worry about turning compost... that pile has always been able to take care of itself.
Kind of surprising to read about someone thinking that extra processing was required...

stone wrote: ↑Tue Jan 05, 2021 7:03 am that pile has always been able to take care of itself.
Kind of surprising to read about someone thinking that extra processing was required...

It WILL take care of itself but will break down faster if you turn and fluff it up. My DH has a garden tractor with a bucket and he turns our pile periodically so it's no work for me and it breaks down really fast. I love it. I also like that by him turning the pile coarse things like corn stalks can be buried. Just look at that beautiful compost. That was totally created from veggie scraps, weeds, grass clippings, and chicken coop debris. No soil was added.

DSC01742 by Brownrexx, on Flickr

I add them to compost.

Bower wrote: ↑Mon Jan 04, 2021 6:32 pm Last year I dug some into my container soils, which seemed not to bother anything. I may try that again this winter.
If you mixed the coffee grounds into some potting soil (which is moist anyway but aerated) I don't think you would get any mold.
The bigger thought in my mind, how much would really be toooo much to mix into your potting mix. IDK. Maybe the sky's the limit.
Maybe we need to experiment?
If you have an unused half pot of soil kicking around, why not dig the grounds into that. If it did turn out to be too much N or too acidic for the plants in a 50-50 mix, you could always use it to sprinkle on or dig into your beds when spring comes.
I have a lot of eggshells as well, so I would probably try to combine the two.

I actually have been wondering what to do with soil I used in a grow bag... do I dump it out or just amend and reuse? I did fertilize the soil regularly so maybe it's not "used up." Is there some other concern? I could just start dumping coffee grounds into those I guess. I could also toss them into my front beds. It didn't occur to me really to just throw them fresh out into the beds and turn them later... I had in my head using them as an amendment when it came time to turn the beds for spring.

I'm like Stone and make minimal efforts with the compost, just pile it and then break it up a year later when it's about done. But I will admit to garden-tractor-bucket envy!! Our winters are too snowy and messy for me to toss anything on 'beds' and not expect it to end up in the path, so it's easier just to prep a composting spot that is fairly accessible and let the snow cover my kitchen scraps there until spring. (in theory. in fact, it is much chowed by animals especially snowshoe hares, but oh well they convert it back anyway, don't they? ) Yes, composting is pretty effortless around here...

“Many vegetables like slightly acidic soil, but tomatoes typically don’t respond well to the addition of coffee grounds”

Read more at Gardening Know How: Composting With Coffee Grounds – Used Coffee Grounds For Gardening https://www.gardeningknowhow.com/compos ... dening.htm

https://www.ruralsprout.com/coffee-grou ... he-garden/

One more link advising not to use coffee grounds.

Hm, interesting, thanks! One more reason to just take the lazy way out and dump it in my front (flower) beds as I go along.

Used coffee grounds are not acid.

I recall reading up to 25% of your compost can be coffee grounds. I don't know what that comes out to for % of overall soil used.

If your beds or ground is fall prepped, dig a trench and dump your grounds, coffee filters and all veg. scraps. Critters don't bother this. Cover after ground thaws and plant into this. Filters break down slowly. Pick them out if it you want.