I've been using coffee grounds, all kinds, for years. I get 200# of grinds per week from star!ucks. Be careful not to add too much straight grinds into the soil, the grinds take a long time to break down. I stopped adding straight grinds to my garden a year ago and only add well composted grinds. They compost well in a tumbler mixed with equal parts dry leaves from the fall. Do an experiment with 10-20% grinds in potting soil and plain potting soil and watch what happens. Also spent grinds are not real acidic as they lose acidity when brewed into coffee. I would only add 1/2 cup to each hole, mixed in well, before planting. I would also like some feedback from others who use lots of coffee grinds.

Compost pete, do you use the grounds after planting, i.e., as side dressing during the growing cycle? Could they be incorporated into water and then used to water container grown tomatoes and other veggies?

ditnc,
I only use the grounds after they have been in a composter for 4-6 months. Straight grinds right out of the coffee maker are very, very, slow to break down and the nitrgen is tightly bound-up. IMHO I do not think they would work well as a side dress or foliar spray if they have not been composted.

Is there any proof that they are good for deterring some pests?

Im curious as to why you would worry about flavorings in the compost when you don't seem to be worried about them in your coffee?

Mulio, maybe she doesn't want hazelnut-vanilla tomatoes?

I use grounds as mulch in my pepper bed and it has worked well. I use grounds from a local shop that sells a lot of flavored coffee, and also my girlfriend drinks hazelnut. It is a good mulch and hasn't hurt the plants. I put it on damp and smooth it out. It makes a fairly attractive cover and the worms dig it.

I was told that flavored grounds are as good as unflavored. When I was in Real Estate, we marveled at how lush, quick growing and healthy the large container plant on the floor in the main lobby was. Come to find out, the managing Broker always poured his leftover coffee on it before refilling his cup. Also, many, many years ago I read that coffee grounds put on the ground around the foundation of your house keeps ants out.

Do coffee grounds repel pests?- I do not know, the caffeine and smell may repel something. A camel non-filter cigarette has been used to de-worm goats because the nicotine does kill intestinal parasites, but I have not heard anything about caffeine or coffee. Earth worms do love grinds mixed into the soil, but I do not see them in any of my piles of straight grinds. If the flavor of the ammendment carried thru to the taste of the fruit, my tomatoes would taste like the underside of a horses tail!!

I came in to ask the same question about flavored coffee grounds - I wondered if the flavoring which is some kind of oil I hear, would be harmful. I'm going to guess a little will go a long way on this one. I have a lot of coffee grounds saved, only some is flavored so thought I'd mix about a cup into the soil for each container as my way of recycling and if there's a benefit to the plant, great! :)

Might the question be, is flavored coffee ok for you? :-)

Might the question be, is flavored coffee ok for you? :-)

True but more relevant is do coffee grounds of any kind do anything for tomatoes?

Since there is lots of scientific testing and anecdotal evidence to the contrary I wouldn't worry about whether they were flavored or not. I'd just add them to the compost pile where they can actually have some benefit.

Dave