Yellowing garlic leaves

The tips of my garlic plants are starting to yellow, anyone know why this might be ?

The tips on ours have been yellow for a couple of months now, all the new growth now it is warming up and staying damp is nice and green though. I think if there is a lock up of nitrogen  in the soil for whatever reason the leaves yellow slightly. Somebody else will know more about that than me but i think if you give them a feed of chicken manure pellets or similar they will be fine.

Totty

(SNAP)

Worm feed would be fine -- they just need a nitrogen boost, probably because the heavy rain has washed a lot of nutrients down deeper.

Thanks worm liquid it is as my wormery produces a lot of this and no worm compost, but thats another question