well if it is too acidic I would recommend agricultural hydrated lime instead of wood ash, Though, wood ash as I have been told is a good source of certain micro nutes. With soil mixes I tend to have the opposite problem of soil being too alkaline. For that I just started using this organic soil acidifier which seems to be working pretty well so far. that and some bone meal and I was able to get my soil from 7.5 to 6.5-6.0 in a week or so. I work with organic veggies as well and the best soil mix imo is 1/3 peat moss 1/3 vermiculite and 1/3 of compost made of at least 5 different types of organic materials. (most compost sold in stores is made from a single type of organic matter with limited nutrients. kitchen compost is always best.) For my cannabis plants I use the same thing except with the added ph adjustments, a solo cup full of wood ash, and a good sprinkle of bone meal. I am sure as I progress my methods I will add and adjust this mix but so far this mix seems to be working great for my ladies. they seem to get plenty of nutes all through the cycle.