Coffee Grounds: Your Gardens New Best Friend or Foe?

Coffee Grounds: Your Gardens New Best Friend or Foe

Coffee is a favorite of Americans all around the country.  Most of us rise every morning attending first to our coffee fix.  Americans spend countless dollars each year at coffee houses.  All this coffee consumption leaves many used coffee grounds in its wake.  Recycle and benefit your garden by utilizing used coffee grounds as part of your regular routine.

Why Coffee?

Coffee grounds have great versatility in the gardening world.  They can be helpful for multiple things, such as a substitute mulch, preventing weeds, acting as a repellant against cats, killing slugs, and fertilizing the soil.  Coffee grounds can also be used to attract earth worms and aide in the acidifying of soil.  It has even been used as an aerating agent by working grounds into the soil.

Is the Hype Really True?

While coffee grounds have been hyped up to max, little actual research has been conducted on its benefits.  As it turns out there is some truth to these claims.  It seems the grounds are unable to kill or deter pests, but all is not lost as they do have wonderful antimicrobial properties.  In the science lab research has shown that fungus rots and wilts were prevented with coffee grounds, but it is likely this is not applicable in the uncontrolled setting of the real world.  Despite this, coffee grounds do seem to have significant fertilizing potential as they contain nitrogen.  This vastly improves the fertility of the soil.  Be careful though, coffee grounds are not a good substitute for plant food as they can impact microorganisms in the soil, affecting your plants growth and soil pH.

While pH tests have shown acidic properties found in coffee grounds, it appears they are excessively acidic and thus should not be used directly on soil.  While some plants are inhibited by coffee grounds others see increased yields if the grounds are used for mulch or compost.  The same effect is seen with germinating plants, some are enhanced while others are inhibited.  Thus, for the typical gardener it will be difficult to discern when to use coffee grounds as it can be vastly different from plant to plant.

So, How Can Coffee Grounds Benefit My Garden?

Despite some of the negative findings of coffee grounds, used properly they can be a huge benefit to your garden.

Compost, Compost, Compost

Coffee grounds can be easily repurposed by adding them to compost.  Up to 20 percent of your total volume of compost can be coffee grounds.

Mulch Sparingly

Coffee grounds can be used as mulch, although it is imperative to avoid using it too thickly and preventing air and water from passing through.  When using coffee grounds to mulch take care to spread it thinly, going no thicker than half an inch.  Finish the process by covering the grounds with 2-4 inches of shredded bark, wood chips, or compost.

Check pH Beforehand Coffee grounds can be a great asset to acidify your soil (if need be).  Conduct a soil test to measure pH.  If your soil warrants acidity, work coffee grounds into the soil up to 8 inches in depth.