“Annie another way to conserve water is to use old coffee and grounds as fertilizer. It’s important to be clear about your goal though, because while coffee grounds add nitrogen to compost, they will not immediately add nitrogen to the soil around your plant if you put it there. Only unwashed coffee grounds will raise the acid level for acid loving plants. Rinsed coffee grounds are neutral and don’t provide the acid.
The soil around the plants will retain water more and better when coffee grounds are added because it softens the soil and makes it more amendable to plant growth. Also adding coffee grounds helps the soil determine how much water it needs and discards the excess. Grounds are an excellent deterrent to snails and cats, however friendly aerating worms love them. Coffee grounds discourage the growth of certain fungi.”
Collect coffee grounds and put on a bakers tray (crisscross gaps in the bottom). Be sure to lay paper in the bottom to increase absorption
Allow to dry in a sunny space that allows for air circulation
After a couple of days in the sun the grounds should be dry. Check to be sure the grounds look like freshly ground coffee. If not leave for a day or two longer
Store the dried grounds in air-tight glass jars
The grounds should be good for up to two years by keeping them in a cool dry place and airtight.