Here's an article from Lizzie Bennett of Underground Medic, a website that is no longer around where this was originally published. ~ Daisy

18 Uses For Wood Ash
Wood ash is suitable for much more than the compost heap.

Wood ash is composed of calcium, potassium, phosphorus, and magnesium but also contains trace amounts of iron, manganese, sodium, boron, zinc, copper, and molybdenum. As it's alkaline, handle it with care, especially when it's wet! And never mix it with nitrate-based fertilizers unless you actually intend to produce ammonia gas!!

Did you know that:

Putting wood ash on an ants' nest forces them to relocate…the ash seems to cause them problems so they pack and leave.
A pan of ash in the corner of a basement or other dark area will deter mice and roaches…not tried that one but assured by a friend it works.
Decent-sized lumps of wood charcoal will filter impurities out of water.
Wood ash in a metal or ceramic container will dehumidify a damp space very well.
Putting ash on a fire will snuff the flames instantly. We actually keep a decorative bucket of it near the fireplace just in case an ember hits the carpet.
Neutralise acidic soil by adding wood ash, never use around tender young plants though as it's too strong and will kill them off.
Sprinkling wood ash around the edge of a young plant bed will deter slugs and snails from having a midnight feast. If they don't like its drying effect on their undersides, re-apply after rain.

At up to 70% calcium carbonate, wood ash can replace lime in a pinch.

If you keep chickens ash mixed with sand makes a great dust bath for the birds.

Make soap. Here's a recipe

Ash on paths and driveways prevents slipping and melts snow and ice. It is messy as hell, so make sure you have a mat so boots can be wiped before coming indoors. A bag of ash in the trunk is great for giving some grip if you get into a wheels spinning but going nowhere situation.

The mildly abrasive nature of ash makes it excellent for cleaning up dull silver, metals, and cloudy glassware. Make a thick paste and rub lightly. leave a few minutes and then polish off. Always wear gloves…it's caustic.

Wood ash neutralizes bad smells. Great for home gyms, sheds, garages, etc; replace with fresh ash every few days.