It depends. Do you want to plant a vegetable garden, or a flower garden?
If you just want to plant a flower garden, it's not too late. You will just have to buy actual flowers rather than starting from seed. (much easier this way anyway) =]
Although, it might be a little late to plant a vegetable garden... I tried to plant a vegetable garden one time, and it turned out to be too late in the summer for it. Nothing grew very big. It was dissapointing. =[
