The Signal Tribune newspaper

Filed under Garden Variety

Grounds for coffee

Hang on for a minute...we're trying to find some more stories you might like.

Email This Story

Jennifer E. Beaver

It all boils down to coffee.
I love talking to other gardeners because I learn so much. In the past month, I’ve had the honor of discussing edible gardening with members of the Long Beach Gardening Club and the Lakewood Community Garden. Both are outstanding organizations with lively, interesting, knowledgeable members.
Three questions popped up related to the same unlikely subject— coffee.
When asked, Can I use coffee grounds on my plants?, I answered with my usual rap. Coffee is fine on acid-loving plants like azaleas, blue hydrangeas, camellias, gardenias and blueberries.
Well, at both meetings I was gently told that coffee (and coffee grounds) enhance everything! So I did some research, and here’s what I found:
Most experts say coffee grounds are wizards in the compost bin but should be used sparingly as a top dressing, and then only for acid-loving plants. Be careful using it on fruiting plants such as tomatoes. Coffee grounds add nitrogen— essential for leaves and green color— but may cannibalize soil’s phosphorous, which is necessary for flowering and, eventually, those ripe tomatoes.
If this is too much chemistry for you, as it is for me, I suggest sprinkling those used grounds sparingly and see what happens.
The next question: What type of worms is used in worm bins, and where can we get them? The answer is red worms, or red wiggler worms, and you can get them on Amazon. I am not kidding.
But what, you ask, does that have to do with coffee? Turns out that worms like coffee, too. When intrepid Washington master gardeners used up 270 pounds of coffee in their worm bins, they found that these happy wigglers produced high-quality compost— and lots of it. Worms can eat and expel their own weight every day. Use the grounds soon after brewing to avoid souring, which attracts fruit flies.
For more on composting and vermiposting (composting using worms), attend a free workshop. Stop by the LA County-sponsored event on Nov. 12 from 9:30am to 11am at Birney School, 710 W. Spring St. ( On Nov. 19, visit a Long Beach-hosted session at 2929 E. Willow St. from 10:30am to 12:30pm ( Discounted bins will be available.
The last question: My basil plant isn’t doing well; what can I do to help it flourish? Well, by now I bet you know the answer: Coffee. According to Organic Gardening magazine, spraying undiluted, cooled coffee on basil plants gives them a boost.

Jennifer E. Beaver, a Wrigley resident, is a master gardener and author of Edible Gardening for California.

Leave a Comment

If you want a picture to show with your comment, go get a gravatar.

Serving Bixby Knolls, California Heights, Los Cerritos, Wrigley and Signal Hill
Grounds for coffee