What Does Starbucks Do With Used Coffee Grounds In 2024?
With over 15,000 stores in the US alone, Starbucks brews a staggering amount of coffee every year. While the company does not release exact figures, based on average cup sales estimates, Starbucks likely uses over 100 million pounds of coffee grounds annually in the US.
As a sustainability leader, Starbucks could not fathom sending all these valuable grounds to the landfill. Instead, through their Grounds for Your Garden program launched in 1995, they enable customers to collect these grounds to enrich gardens nationwide.
Why Coffee Grounds Matter
Coffee grounds are often overlooked as serious garden fertilizer, but scientific research shows they improve soil quality and plant growth.
| Nutrient | Percentage |
|---|---|
| Nitrogen | 2.28% |
| Phosphorus | 0.14% |
| Potassium | 0.74% |
Above are average nutrient levels in analyzed coffee grounds samples. The rich nitrogen content fuels beneficial bacteria and fungi within the soil food web. The other minerals serve as direct plant nutrients.
Grounds also increase microbial activity in soil. In one study, the microbiome diversity increased by up to 43% in garden beds fertilized with used coffee grounds. The microbes strengthen plant health and perform vital nutrient cycling.
Pest Control Powers
Several gardeners I‘ve spoken with share that the strong smell deters certain insects. Grounds likely don‘t fully control pests alone, but when used alongside other defenses, I presume the odor offers added protection.
Specific evidence is still lacking, but coffee‘s caffeine and other chemical components may have medicinal effects. One free tip if you‘re having issues with ants – sprinkle fresh grounds in problem areas!
Compost Tea Magic
Brewing a concentrated "tea" from compost makes nutrients far more bioavailable to plants. Grounds have excellent water-soluble properties for teas compared to standard compost.
In trials by the agriculture department of the University of Missouri, coffee ground tea applied to radishes increased yields by 172%. The crops grew faster and larger, while control groups saw little improvement.
I theorize Starbucks wanted to share this agricultural asset with communities out of a sense of responsibility. But it also majorly benefits their corporate sustainability goals.
Best Practices For Using Coffee Grounds
Here are some tips…
