Why isn't my rye producing flowers?

So I've tried rye grass in a couple of locations and it's just basically getting to the size in these photos and then turning yellow and dying back.

Wheat grass is doing the exact same thing - but strangely barley and oat grass is doing very well and producing abundant flowers.

Am I doing something wrong?

I know the soil is good in nitrogen, and phosphorus, and the pH is around 6-6.5.

http://imgur.com/a/UHJT5