Make great use of all the Flower arrangements from the ceremony at the reception hall - Discuss your options with the Florist to decorate the reception site with additional flowers and pedals. The following are some noticeable areas that could be decorated with the same color or schemes of the center pieces:

To decorate the cake with your choice of flowers/pedals

To decorate the following:

Place card Table

Gift Table/Money Box

Main Table/Bridesmaid and Groomsmen Table

Tea Table/Fruit Table/Desert Table

Bar Counter
Also, to reduce cost, have your florist use the center pieces which will be used at the reception hall, to be used as aisle decorations at the church.
Discuss other options which you may have for additional decor and decorations both at the ceremony and the reception site.