I have the same question myself. I actually started the geranium seeds march 8th and they are sprouting. I think we missed the prime time but why not start anyway and plant them out when they are mature enough. Then when it starts to get cold we can have them as houseplants? My sister does this and it always has flowers on it in her window. And she is by no means a avid gardener. I read of people taking cuttings of the plant right before spring and starting new plants. So even if you can't get a long period of blooming outdoors you could help to better plan for them next year by taking cuttings! Just an idea!