If you have fairly mature gerbera plants try the following first. Water well. Now use a slight lifting action around the plant. Reach into the center of the plant, teasing gently. It is very possible that you will find yourself lifting out the whole center of the plant or young plants that have formed in the crown. Pot these and shade until hardened off. Gerbera flowers best when the crown is kept thinned out. If you do not want to increase your supply of gerberas, just be ruthless and thin (pull out) the centers.

Thank you for the detailed reply Nadina. I tried this but maybe my plant is still not mature enough? I tried to 'tease' the center out but it didn't budge so I left it alone. I bought it about 2 months ago from the nursery and it had a single flower at the time.