They'll keep growing. My second year cascades are doing well, but the Willamettes are toast. I'm going to dig them out, for whatever reason, they don't like it where I planted them.
Adding some compost or fertilizer is always a good thing. I take a little compost, put it on top of the soil, then when I water the nutrients from the compost go down into the soil.
Congrats on the hops - they're looking good!