I hosted a garden themed party (the guest didn't know until the arrived), I have fresh flowers in a water can, flowered plates, gave game gifts like gardening gloves, etc......
My budget favor was I got the cheap flower seeds like Wal-Mart, Meijer has that are like $.59 each, wrapped them in cheap toole (sp?) and tied with a ribbon in the color of the wedding.
A few of the ladies told me later at the wedding they planted them and they were pretty!