This ‘common’ kitchen ingredient has ‘amazing’ benefits when used in the garden

You can also spread the grounds over the mulch. If you do so, make sure it is in a very thin layer, as too thick of a layer won’t allow air or water to pass through.

Place the grounds on the soil, then cover with a layer of organic matter, like shredded bark, wood chips or compost. 

Because of the coffee ground’s high acid content, it can be used to balance the pH of soil. If your soil is too alkaline, dig into the soil and add the grounds at a depth of 17 to 20 cm.