The inside is getting yellow from lack of sunlight and no other reason. If they are as thick as you say the sun can't reach the middle. Your patch should really be thinned out, but I have no idea how you'd go about it.

I wonder if maybe I planted them too close together. I followed the directions. I planted them about 12 inches apart and about 5feet between the rows. They are Jersey Giants, I hope they will survive. Next year is the third year so I can do a full harvest,right? Maybe it wont get so thick because I wont be letting them grow into ferns like I did this year. I sure would hate to loose them after coming so far.

They are fine. Just allow them to be until next spring. Then harvest more. or dump some compost over the patch this winter. Wait until winter is good and frozen.

Asparagus always turns yellow.

My patch is over 25 years old. still going strong.

The weather patterns are changing all across the country. I don't know what the weather's like wherever you live but your asparagus plant does. Like was said, asparagus ferns will turn yellow and it's perfectly natural. Once most of them yellow you'll want to cut them all down and clean-up your bed, then wait for spring and a new harvest of asparagus spears.

Greg
Southern Nevada