Fireplace Ash---Is it OK to spread on your lawn? environmental impact?

Fireplace ash contains lots of potassium, as well as traces of other plant nutrients, so it is a fertilizer. It is also strongly alkaline.

If you live in an area with acidic soil, and you haven't spread lime lately, ash will make the soil less acidic and it will be easier for plants to absorb nutrients. If you have alkaline soil, which is most common in deserts, it might do more harm than good. But wildfire is natural everywhere, so every soil can handle at least some ash.

Spread the ash widely, because it is fairly easy to overdose.

Yes it is. The high carbon content helps promote a good garden.The best evidence to support this is volcanic soil. Most areas that have had volcanic activity, or even forest fires have always grown back lush and vigorous. I store my fireplace ashes in the basement until I get ready to plant. I till up the soil and add generous amounts of the ash with my fertilizer. I ALWAYS have a great turnover of vegetables and flowers. However, bring some of you base soil to a garden shop and have it tested for ph levels, as you want to insure a good balance.

Fireplace ash is not toxic to the environment, it's technically just burned wood. So long as you're not using chemical logs or fire starters. There should be no problem throwing it outside. The chance that the ash will blow back in your face if there is the slightest breeze may persuade you to be standing in the right location when it starts to fly.

I spread it around my garden and shrubs. Been doing it for year and they love it. I would not dump it on my lawn though..too strong..might kill it in that spot.