You should deadhead whenever your geranium blooms begin to look brown or weak. ... Deadheading will encourage new, full blooms to grow in and replace any that look weak or less full. Work through your plant, doing this throughout its sections. You'll begin to see fresh new blooms in just a few days.

What happens if you don't Deadhead geraniums?

This pretty annual plant cleans itself by dropping the flower heads below. The plant will continue to flower all summer long with no extra work from you spent removing it's pretty blooms.

Should I cut the dead heads off geraniums?

Geraniums are easy to care for making them perfect for low maintenance gardens. They do not need to be pruned but they should be deadheaded regularly. Wilted flowers will needlessly drain the plant of its energy and this will prevent the plant from growing further flowers.