We produce a huge amount of used coffee grounds every month, and all of it goes into the compost. Can we use some of it to fertilize our lawn too?
Used coffee grounds slowly release nitrogen, phosphorus and other trace minerals into your lawn, making coffee an effective natural fertilizer for grass on mature lawns. Do not use them on new lawns, however, as the dense clumps of coffee grounds can prevent seedlings from growing.
Let’s dive down in more detail into the subject of using coffee grounds as lawn fertilizer, and discover why grass loves it, and how and when to apply it for best results…
Will Coffee Grounds Hurt My Lawn? (or Kill My Grass?)
Coffee grounds won’t hurt your lawn – in fact, your grass will love this nitrogen and phosphorus-containing treat.
Used grounds slowly release these nutrients, plus other trace minerals, into your lawn, making coffee a great natural fertilizer for grass.
The worms also love it, so they’ll soon get to work on aerating the soil when they wake up and smell the coffee. Even better, pests like slugs and snails don’t appreciate the rich aroma and will keep away.
However, if you’ve recently sown a new lawn, coffee’s not the best fertilizer to use. The dense grounds can prevent the seedlings from growing.
On the plus side, coffee grounds also inhibit some types of weeds, but you don’t want to risk smothering your new grass.
How Do I Use Coffee Grounds as a Top Dressing Fertilizer on My Lawn?
You can simply scatter the used coffee grounds on the lawn, then rake them to prevent clumps forming. However, it’s far more fun to make a bucket spreader.
- Get an old, small bucket
- Drill a few holes in the bottom (¼ inch holes are good)
- Put the grounds into the bucket, then walk across the lawn with it, gently shaking out the grounds evenly
Repeat this every month or so to give your lawn an enriching treat.
Can I Use Coffee Grounds on My Lawn in Winter?
We generally don’t use fertilizer on our gardens during the winter months, when many plants are dormant and the ground is hard.
If you’re getting a build-up of good grounds over the winter, you can either stick them in the compost ready for next season, or if you have the space, freeze them. They’ll quickly go moldy if left, so if you want to stockpile for the spring, you’ll need to freeze the grounds.
Can You Put Coffee Grounds Directly on Soil?
Yes, you can sprinkle coffee grounds directly onto your soil as a slow-release fertilizer. However, be mindful of how you do this, or you could find yourself with an impenetrable barrier of coffee, which actually prevents rainwater and nutrients getting into the soil.
How does this happen? Well, we’ve talked a fair bit about how coffee is extracted. Grounds are designed to be difficult for water to pass through, because as the water moves slowly through the coffee in the filter or portafilter, it picks up the maximum flavor.
Slowing the water down makes your cup of joe more aromatic – but when it comes to gardening, it interferes with the natural drainage of the soil.
It’s simple to overcome this: just scatter the coffee grounds thinly (like the bucket method we mentioned), or give them a quick rake to separate any clumps.
If you want to find out more about using coffee grounds as fertilizer, this short film is a helpful guide.
Are Coffee Grounds Good for St Augustine Grass?
Coffee grounds are a helpful fertilizer for your St Augustine grass. It’s a pretty tough grass that tolerates humidity, so it’s popular in warm, coastal areas.
However, St Augustine is also a thirsty grass, so if you’re spreading coffee grounds on your lawn, it’s super-important that you spread them finely.
Coffee grounds will naturally clump together, and as we mentioned above, this can mean that they form a dense barrier, which in turn can affect drainage. Make sure you’re not preventing water from reaching the roots of this thirsty type of grass.
Do Coffee Grounds Prevent and Kill Weeds?
Coffee grounds are what’s called “allelopathic”, which means they can inhibit the growth of certain types of plants.
The grounds will help to suppress weeds in your lawn without harming the grass. If you’re looking for an eco-friendly way of keeping the weeds down, try adding coffee.
Will Coffee Grounds Kill Clover?
Coffee grounds will suppress some weeds, and that includes clover. At the very least, they’ll slow its growth.
If you want a clover-strewn lawn (don’t forget how much the bees love this plant), don’t use your old grounds on the grass, but save them for the compost or the soil.
However, if you want a smoother lawn without clumps of clover leaves, coffee is a good natural way to help you achieve this.
Do Coffee Grounds Kill Moss?
While coffee grounds don’t kill moss directly, they can still help to keep it down. How does this work? Well, the natural fertilizer strengthens the grass, which makes it more able to withstand the moss.
The moss can’t compete with strong and healthy grass, so won’t take over the lawn.
Do Coffee Grounds Attract Rats?
To be honest, rats are pretty neutral about coffee grounds. They aren’t repelled by the strong aroma of the used grounds on your lawn, but neither do they come scampering over for a caffeine fix.
It’s possible that the pungent smell of the coffee masks other scents, both good and bad. Be aware of this if you’re trying to keep the rats away using natural deterrents that rely on scent.
Will Coffee Grounds Repel Dogs?
They may be man’s best friend, but dogs don’t share our human love of coffee. If you want to stop your pooch from digging up the lawn, a good scattering of coffee grounds may be enough to make them break the habit.
Likewise, cats aren’t coffee fans either. If you’re having problems with the local cats (or your own kitty) littering in the flower beds, add a good scoop of coffee grounds to the soil.
Do Coffee Grounds Keep Moles Away?
Unlike rats, moles have an opinion about the smell of coffee: they really don’t like it. If moles are digging up your lawn, a good sprinkling of coffee grounds may be enough to deter them. It’s certainly worth a try before calling pest control.
Skunks aren’t too fond of the scent of coffee either (the irony), and it may even keep the raccoons out of your backyard.
With these guys, you may have to identify the weak spots where they’re getting in, and place a bowl of used ground at the site. Sprinkling them around won’t be as effective.