We've had some crazy weather in Georgia this year. It's possible that more asparagus will come up as the temps warm up and stay up. If not, you will need to plant more, so that they are spaced approx 18 inches apart. Leave the ones that have already turned to ferns. They will die back next winter, and then trim the dead fronds back.

I've grown asparagus before. They would still be producing right now, but I totally changed my gardening area. Asparagus are sooo easy to grow. And homegrown asparagus taste so awesome that they are worth any trouble at all. I'm a little late planting my asparagus roots [ yep, I'm cheating. ;) ], but I'm going to plant them anyway.

GA Extension Info:
http://apps.caes.uga.edu/urbanag/Home&Garden/indexFS.cfm?storyid=2242

Good info:
http://newstimes.augusta.com/news/2012-01-08/proper-preparation-is-the-key-to-growing-asparagus

Here is a link that might be useful: Growing asparagus from seed