I was reading up on garlic fertilizing, and was wondering how much potash to give my garlic plants. I don't know much about it, except the fact it is garlic from a single clove off a bulb.
Garlic’s demand for K ranges from 125 to 180 kg K2O/ha (Bertoni and Morard du L. Espagnacq, 1988; Zink, 1963).
If you're autumn planting where this is Oct-Nov, then the RHS advises
Apply a general fertiliser, such as Growmore, at planting time at 2oz per sq yd (50g per sq m) followed by a light dressing of 1oz sq yd (25g sq m) of sulphate of potash in February.
But if your soil has plenty of potassium, you should not need to add more.