Hi,
I just throw mine in the composter, if you have one. My grandmother used to keep the eggshells in a jug with water to use on her geraniums. She watered with it 3 times a week and they were beautiful.

hi marlene
i use the coffee grounds and egg shells to keep slugs away from the plants.....they don't like things with sharp edges..works well for me...
cheers

eggshells provide calcium. Coffee make good compost. Take the eggshells and crush them to a powder and you can dig this into the soil. If given the chance I would use sea shells too. They provide calcium in the same manner - just crush them well.

Sorry to say, egg shells aren't a significant source of calcium. Ca is a trace element that plants need to guard against disease (such as blossom end rot on tomatoes). There was a university study earlier about using egg shells as a source of Ca; I'll see if I can find it again. You might be surprised. The researcher boiled the egg shells and found that the water barely had any Ca in it. I can't say for digging egg shells into the dirt though.

Do be careful with coffee grounds. Too much could be devastating for plants that like alkaline soil.

I've heard of burying banana peels a few inches from the base of the rose bush. Bananas contain a lot of potassium (which plants use for root and bloom development). I do bury the occasional banana peel near my rose bush, but I don't know for sure if there is enough potassium in the peels to be significant source for the roses.

Also one last thing to keep in mind is that N-P-K is needed is specific forms that the plants can use (ie: the atmosphere is 95%+ nitrogen gas but plants can't use it in its gas form).

I did a mix of eggshells and tums - ground them up in my food processor and sprinkled that around my tomatoes this year. I'm hoping to alleviate blossom end rot, so we shall see..

As far as the coffee grounds go, I dumped about two gallons of them around my one (ancient and largish) rhodadendrum and two holly plants early in the spring. The Rhodi loved it and had more blooms than I've ever seen on it. One holly nearly tripled in size (and this after 3 years of literally 'no' growth). The other didn't seem to respond either positively or negatively. I think the coffee grounds are pretty acidic, so as a previous poster mentioned, you have to be careful about the application. Nonetheless, I was totally thrilled with what the coffee grounds did for me!

if you need calcium, you can try dissolving calcium carbonate tablets in water

Coffee grounds are only slightly acidic with a pH of about 6.2. Also:

Nitrogen: 2.28 percent
Phosphorus: 0.06 percent
Potassium: 0.6 percent

There is more nitrogen that becomes available as soil microbes break it down into a usable form. Great for the compost or soil if not piled up as it will become hydrophobic.

tj

Here is a link that might be useful: The Grind on Grounds

I collect my eggshells, rinse, dry, when I have enough, I put them on a plate and microwave for 3 minutes on high -- this sterilizes them and makes them somewhat more brittle. Then, the whole mass goes into the food processor, and comes out as a near-powder.

This powder goes into the chicken feed dispenser along with layer mash and cracked corn -- to be eaten by the very chickens from whence the eggshells came. A cheap and convenient way to supplement their calcium, since they need a lot of it all of the time.

What goes around comes around, doesn't it? :=)

This does not directly answer your original question regarding egg shells & coffee grounds around flowers, but as an aside, I use coffee grounds in the planting hole when I set out onion bulbs - keeps the dreaded onion maggot off.

No kidding, I used to struggle with wormy onions until a fellow gardener told me about the coffee grounds trick. So far it has worked for me. And it's totally organic.

I want to thank all of you who answered my question. I posted this in April and just now receiving a lot more answers. Thanks again.

Hi Marlene, That's funny the time that answers continue.

I'm relatively certain that I can't damage the soil with too many coffee grounds around the acid-loving plants in my alkaline soil. My Minnesota blue hydrangea bloomed pink for the second year just as the neighbor said it would and while I don't care to kill it, this spring I ignored the delicate measured administration of cotton seed meal, and dug into the drip-line soil all the rest of the bag, resulting in a darker pink. Not to be put off, I plunged one of the blooms into blue colored water and watched it turn neon on the kitchen table.

If I can avoid it, I try not to buy things to amend my soil, so your question reminds me that either Caribou Coffee or Starbucks bundle coffee grounds to give away. Since I'm in a metropolitan area, I believe I will pick up quantities at next opportunity and see if the hydrangea wants to play tough again.

Thanks to you, today I have emptied the breakfast coffee grinder around the base of my red rose (the cold-surviving Margaret Chase Smith variety), carefully distributed it to prevent hydrophobia, and crushed the nuked(1 minute) lunch-salad egg shells to strew among the lettuce vs. slugs. Not fond of slugs. Thanks for your question.

Here is a link that might be useful: Master Coach

Hate to sound stupid, but what is hydrophobia got to do with plants and what is it?

"...what is hydrophobia got to do with plants and what is it?..."

It scares the water from plants ;-).

Seriously, it means the coffee grounds can form a barrier that repels water if put on too thick. Incorporated into the soil this barrier can't form and water passes through it, but piled thickly on top of the soil and the barrier can set up. If saturated with water, the barrier will break down, but rainfall will bounce off at first.

tj

Here is a link that might be useful: Hydrophobic Effect

I am new at gardening, I would like to know much coffe grounds and egg shells to use on one rose bush?