Lucerne hay, a nitrogen fixing mulch.
Personally I use it spent after the rabbits have a go at it for bedding, bunnies are good like that, enriching your mulch. For those who don't have bunnies lucern is far better mulch than anything else on the market. Yes it is expensive but the plusses outweigh the cost. Seaweed is also good. You can't just throw anything on top of plants many will create nitrogen draw down, use more nitrogen than they produce, blocking this essential growth element from the plant. If using other mulch feed with chook poo thickly then mulch as this will counter balance the mulch.
Hops are a nitrogen hungry plant, see the growth rates, with a balanced diet they will do well. If in doubl liquid feed 1/2 strength.