Redeem Your Grounds…Your Coffee Grounds That Is!
So I was at home writing a post when Britt texted me a pic that she had taken while at Starbucks picking up a morning boost…with the message “What a great idea for a blog post.” Her pic was of a sign promoting Starbucks’ “Grounds for Your Garden” program.
Friends have told me about how they’ve gotten coffee grounds from their local coffee shop…but I had visions of it being more of a covert operation…with an amenable, but non-compliant barista…like a drug deal behind the dempsey dumpster. I had no idea that Starbucks had officially sanctioned such behavior…and it seems for some time now…for several years. How have I missed this?
Anyway, Starbucks’ sign goes on to say… “Used coffee grounds are a ‘green’ component for your compost, a natural fertilizer for your garden and FREE at Starbucks. Take some home today – you’ll enhance your soil and reduce landfill waste at the same time. It’s another way the goodness of coffee grows beyond the cup.”
Since we give all of our food scraps to our chickens…and because I’m not disciplined enough to check on a compost pile (which takes very little discipline, by the way)…I’ve not used my coffee grounds in compost. However, I’ll regularly throw clumps of this rich, brown goodness into my raised beds as a treat for our veggies…and into our landscape beds to make our plants happy and green. And when I say throw, I literally mean throw…which at times requires me to retrieve the coffee filter that slipped through my lazy fingers. I realize that this is probably a sub-optimal use of my coffee grounds…but I thought the benefits of my grounds would eventually get to my plants…and besides, they’re better there than in some landfill…as Starbucks suggests.
But this got me thinking…why are coffee grounds so good for my plants and how do I really make the most of them? With that I asked around a bit and I let my fingers do a little Googlin’…and here’s what I learned.
Why Are Coffee Grounds Good for Your Garden?
In a nutshell, adding coffee grounds to your soil has 3 primary benefits (besides the whole “being green” thing):
- They add nutrients to your soil
- They improve soil texture and drainage
- As mulch they deter pests from munching on your veggies or the tender growth of your perennials (e.g., hostas)
1. Adding Nutrients to Your Soil
Although some claim that coffee grounds increase your soil’s acidity level, it’s my understanding now that they are only slightly acidic and really more neutral than anything else…so they probably don’t do as much as some suggest in altering the pH levels of your soil. However, they do offer other nutrients that your plants benefit from…releasing nitrogen, phosphorus, potassium, and other minerals…all helping support plant growth.
Plants that thrive in a nitrogen-rich growing environment will especially appreciate this caffeinated boost. For example: tomatoes, your green leafy veggies, blueberries, roses, camellias, azaleas, rhodies…err, rhododendrons. However, there are also some plants that really prefer not having a cup morning of joe…so to speak…e.g., asparagus fern, alfalfa, white clover, Chinese mustard, geraniums …and other flowering plants. Coffee grounds actually stunt these plants’ growth and inhibit seed germination. Fortunately for me, I have all the plants that like coffee grounds and none that don’t. Woopwoop!
2. Improving Your Soil’s Structure and Drainage
As for improving your soil’s structure and drainage, it’s actually quite simple. Being larger in size than other components in your soil, coffee grounds allow for air and water to flow more easily through your soil and to the roots…allowing the roots to their job of absorption more easily. Coffee grounds will also attract worms…which not only helps the structure and drainage qualities of your soil (as they travel through your soil they’re effectively aerating for you), they’ll also add nutrients by converting organic matter into nutrients through their castings…their manure…their poop. So double-bonus there!
3. Deterring Pests
When using coffee grounds as mulch, your furry pests (e.g., squirrels, chipmunks, and bunnies) don’t want to have much to do with them…so they stay at bay. I’m not certain if it’s the smell or the texture…probably the former. Coffee grounds will also deter slugs…likely because they don’t like the way it feels on their soft underbellies…and some believe they don’t like absorbing the caffeine as they slide on by.
How Do You Make the Most of Your Coffee Grounds?
There are a few ways you can use coffee grounds in your garden:
- In compost
- As mulch
- Amended directly into the soil
Again, due to my laziness and the fact that my chickens eat all of the potential food scrap components I’d use in a compost pile…I don’t compost. But if you do, coffee grounds are a great addition to your pile. Consider them to be “green” material (e.g., grass clippings and food scraps) that you mix in with your “brown” material (e.g., dried leaves, straw, and wood chips). You can even throw in your filters as some additional “brown” material…as they will decompose as well. Be careful though…don’t add too much of this rich brown goodness to your pile (i.e., > 25%) or it may throw off the overall balance of things.
As I mentioned above, coffee grounds can be used as mulch. Simply pile ½-1” of coffee grounds around your plants…but not more than that, otherwise you might be left with a moldy pile of yuck. But a mound this deep will fairly quickly be broken down by the rain, worms, and soil microbes. And again, adding them to the top of your soil in this fashion will also deter those nasty slugs.
3. Soil Amendment
For all the reasons I mentioned above, coffee grounds can be amended directly into your soil. You can do that either when you initially put your plants into the ground or by simply scratching it into the soil rather than piling it up as mulch. Your plants will thank you for the easier access to the coffee grounds’ richness.
This is what I’ll probably do. But more than likely…even after all of this new knowledge, you’ll probably still find me throwing my coffee grounds willy-nilly during my morning strolls in the garden. And if the filter flies into my beds, so be it…as long as you can’t see it that easily, I may just leave it there.
So for you coffee lovers, here’s a reason to love your coffee even more…for giving your plants a different kind of boost than it gives you. And now…the next time you order your half-cafe, double, Grande, 2 pump vanilla, non-fat, extra-hot, Latte…ask for a bunch of coffee grounds on the side. And if you don’t like coffee…go ahead, swing into your local Starbucks with the rest of us and place an order for used coffee grounds. I’m sure your friendly barista will be happy to oblige.
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