Strangely, I had an epic Elephant Garlic harvest of 12 huge bulbs in the garden, but the size of the Solent Wight and Early Purple Wight (both from TGF) were average. Rust this year in NW London was much less bad than the previous year, possibly we had proper frosts in the winter and then we had a very dry period mid-March-mid June (I harvested in the last week of June).
I”m wondering about feeding garlics comfrey tea in future rather than sulphate of potash (like you, I’ve followed TGF’s instructions the three years I’ve grown their bulbs) – I”ve read that onions rather like it during swelling phase so I kind of suspect that garlic will be the same…..I’ve used 50ml of concentrate in a 2 gallon watering can for runner beans and the effect has been excellent this September, so I’m thinking of giving it a go on the garlic in 2016….