I was told by a few people to be careful about using wood ash in the garden. Nitrogen and other nutrient issues being the largest reasons why if I remember correctly.
If your soil could constantly use some lime like mine, then adding ash isn't an issue as when you get ash wet you get lye which is very caustic and acts as a fast acting "lime" on the soil. If your soil is on the base side and needs help with acid, I wouldn't.Hmmm, I'll keep that in mind and do a little more research on it. Thanks for the feedback!
When the pH is wrong it ties up nutrients up in strange ways, so as long as you aren't messing up the pH with the ash it should be fine as long as you don't just smother the garden with it.