In article , HaaRoy
writes
I have always thought that using ash from the bonfire was good for the
plants but am i under a false illusion ?

No, garden bonfire ash from mainly brushwood and similar material makes
a good potash based plant dressing, it is especially beneficial to soft
fruit bushes. The ash should be allowed to mature for several weeks,
longer if you can, then diluted with ordinary soil sifted fine, or a
little sharp sand. It should not be applied directly touching the stems
of plants. Bonfire ash can also be dusted onto compost heaps, or used
sparingly in conjunction with mulches.
--
Alan & Joan Gould - North Lincs.