Does anyone put used coffee grounds in your potted plants?
Is so how often do you do it? Would weekly be too often?
Used coffee grounds in your potted plants?
Coffee grounds have nothing to offer container soils in the way of nutrients and break down quickly, clogging macro-pores, slowing drainage, and creating compaction. Another very important consideration is that c-grounds become very hydrophobic at fairly high moisture contents & would greatly increase the difficulty of rewetting soils that dry down to below 40% moisture, which is still not too dry for most plants. My suggestion would be to resist any urge to include them in any container soil.
Al
I also think they're rather acidic, spread over a garden they are fine, but in a container I think you might make it too acidic.
Al--out of curiosity, I know they're recommended as something to put in garden beds, why is all the stuff you mention in your post not an issue there? Is it just the amount of grounds relative to the amount of soil? Or is it an issue and the people out there saying to use them in garden beds are misinformed?
I don't use coffee grounds in potted plants, but I do give them
a shot of coffee once in a while and it perks them up.
Starbucks has a program called Grounds for Gardens, and
will give you free grounds.
Coffee grouds release nitrogen into the soil. Also, they are
great for all your acid-loving plants - hydrangeas, azaleas, all
your evergreens.
Cutworms hate them and won't cross them. Grubs don't like
them either. Worms LOVE them. And that's all I know.
Actually, used or brewed grounds are neutral in pH and don't acidify the soil.
Coffee grounds are fine in the garden, but growing in the ground is much different than growing in a container. Approximately 50 percent of the "average" in situ (where it occurs naturally) soil is made of pore space. In this "average soil" the total pore space might be occupied by 25 percent air and 25 percent water. Of course when it rains or during a drought these percentages change drastically, but where I'm headed is that container growing radically changes the physics behind soil behavior. The same soil in a container might have a much lower total % of pore space (for the sake of brevity, I'll ask u to take my word on this) and the water holding capacity will be greatly increased. Anything we use that breaks down into finer particulates, particularly those that break down quickly, will further fill macro-pores, increasing water holding capacity. Inverse to the water holding capacity is air volume - severely diminished in containers as soil particulate size decreases.
So, the number one priority in selecting or building/amending a very good container soil is to be sure that whatever the components you use, the soil structure will support air in good volumes (at least 30% at container capacity (when soil is saturated) and a minimum of 50%, up to 75% when soils are dry, for the life of the planting. This cannot be achieved with garden soils, sand, compost, top soil mixtures in your containers. The c-grounds plays into this equation by virtue of the fact that particulate size is small and it breaks down quickly, not to mention the hydrophobic (water repellent) properties.
What I've said here only scratches the surface of the subject, so if you have other questions, I'll be glad to answer if I can.
Al
How'd you get so smart, Al?
Actually, if you only brew the coffee one time and do not
reuse the grounds, they are still pretty acidic. I've had to
make do in an emergency when I didn't remember to buy
coffee and just poured more water into the pot. Yes, the
coffee was a LOT weaker, but it was still coffee. So why
wouldn't it work in the soil to acidify it a bit? What would be
the explanation?
By the way, the information I posted was more or less what
I learned years ago from books by Jerry Baker. I think he hails
from your neck of the woods. At any rate, do you think it has
changed - is there better information? He never did say WHY
the worms loved coffee grounds and it has always puzzled me.
What do you think is the reason?
By the way, my houseplants really do enjoy a bit of watered down
coffee about 3 times a year. I notice that they perk up within a
few days. But I am worried - they seem to be leaning towards
the direction of the nearest Starbuks, LOL.
I always use the leftover coffee and fill up the pot with water, for my indoor plants and my hosta.
Mahnot - ... not particularly smart, but lots of what I see & read just "sticks" with me. I can sometimes even retrieve it for use later - like now I suppose. ;o)
First of all coffee grounds are a very good addition to your composting/gardening efforts. They would be considered a "green" or nitrogen source - C/N ratio about 20:1. Roasted coffee is fairly acidic, almost all of the acid is water soluble and is extracted during brewing. Used grounds have essentially neutral pH, although the coffee beverage itself is rather acidic. The measured pH of used coffee grounds is most often around 6.9, with a significant amount of buffer capacity. That means adding the coffee to either acidic or basic solutions drove either/both toward neutral pH. The exact pH of used grounds will depend more on the pH and alkalinity of the water used in brewing than any factor in the coffee's composition, but with any potable water, used grounds will be close to neutral pH.
Only anecdotal evidence suggests that worms are very attracted to them, but so are they attracted to other organic or vegetative matter. It's a sure bet that worms will not trip on themselves in a headlong rush to the coffee shop. ;o)
It is also widely held that placing coffee grounds under acid loving plants is beneficial. But as the evidence has shown, this may just be a myth since the spent grounds are neutral. I suppose that eventually they will help in adding humic acid to soils, but again, so will any other vegetative product. At best it is a good soil conditioner and will feed the worms and other soil denizens. If you do use grounds in this way be sure to incorporate them well into the soil (hydrophobic @ soil's surface - see above).
Al
Al: You wrote: "So, the number one priority in selecting or building/amending a very good container soil is to be sure that whatever the components you use, the soil structure will support air in good volumes (at least 30% at container capacity (when soil is saturated) and a minimum of 50%, up to 75% when soils are dry, for the life of the planting. This cannot be achieved with garden soils, sand, compost, top soil mixtures in your containers." What do you recommend using for container soils?
Happy - http://davesgarden.com/forums/t/527353/ Read this post (also on Garden Web container forum [sorry Dave] where it has maxed out in number of replies & a second post begun. Total # of replies are approaching 250 I think) & it will prolly answer most of your questions. If not - ask away, but at this point, it seems as though I might be getting off topic & I don't want to hi-jack Joe's thread. U can start another thread or D-mail me directly.
Al
Thanks!
"U can start another thread or D-mail me directly."
I would urge the former, so that everyone can learn and participate. :-)
SB
I just bumped the other thread -
Al, if you have additional comments on soil composition for containers that didn't make it into that thread (http://davesgarden.com/forums/t/527353/), I'd love if you would add it there.
Al, you da man !
Thank you for all the great information. I hate getting old.
Everything I "knew" ain't so anymore. :o (