If you're growing hydrangeas, use coffee grounds to affect their color. Coffee grounds add extra acidity to the soil around hydrangeas. ... Seedlings thrive off the nitrogen content in coffee, so give them a boost by making a natural fertilizer from the grounds.

How do I put coffee grounds on my hydrangea?

Simply layering the coffee grounds on top of the soil is quicker but may result in an ugly pile of mold that looks messy and smells unpleasant. Alternately, dump your coffee grounds into your compost bin and add the compost as part of your twice-yearly fertilizing ritual for your hydrangeas.

Is coffee ground good for hydrangea?

Some gardeners report success in turning their hydrangeas blue by applying coffee grounds to the soil. The coffee grounds make the soil more acidic, allowing the hydrangea to more easily absorb aluminum.