Fertilize plants.
Don’t throw out those old coffee grounds. They’re chock-full o’ nutrients that your acidic-loving plants crave. Save them to fertilize rosebushes, azaleas, rhododendrons, evergreens, and camellias. It’s better to use grounds from a drip coffeemaker than the boiled grounds from a percolator. The drip grounds are richer in nitrogen.
Deodorize a freezer.
Get rid of the smell of spoiled food after a freezer failure. Fill a couple of bowls with used or fresh coffee grounds and place them in the freezer overnight. For a flavored-coffee scent, add a couple of drops of vanilla to the grounds.
Boost carrot harvest.
To increase your carrot harvest, mix the seeds with fresh-ground coffee before sowing. Not only does the extra bulk make the tiny seeds easier to sow, but the coffee aroma may repel root maggots and other pests. As an added bonus, the grounds will help add nutrients to the soil as they decompose around the plants. You might also like to add a few radish seeds to the mix before sowing. The radishes will be up in a few days to mark the rows, and when you cultivate the radishes, you will be thinning the carrot seedlings and cultivating the soil at the same time.