Garden

It depends on what fuel you use. Ash from coal or smokeless coal fires should not be used in your garden. Such ash contains trace amounts of sulphur and chlorine compounds, which can harm your soil and plants. Please let the ash cool fully, then dispose of it with your normal household waste 

Ash from a log fire, however, is perfectly safe and can be beneficial. You can add cooled log ash:

• To your compost heap, where it helps enrich the material.
• By digging it into bare ground, improving soil quality when preparing beds

Absolutely, but only if it's from a log fire. Log ash is completely safe and makes a great additive to your compost heap, helping to enrich it naturally. However, ash from coal or smokeless coal should never be used in your garden or compost — it may contain trace amounts of sulphur and chlorine, which could harm soil and plants. Please make sure any coal ash has fully cooled, then dispose of it in your normal household waste.