Believe it or not, the ashes that remain from your fire can be a wonderful natural source of potassium for the garden. And the best part it is free!

Wood ash typically is good for plants that enjoy an alkaline soil which will suit most plants. However, there are some exceptions where wood ash should be avoided such as berries and roses as they prefer an acidic soil base. 

When to spread wood ash: 

If you are planning to spread the wood ash into the soil directly, apply it sparingly on the soil and dig in. This will ensure that it is well mixed into the ground and you won’t end up with any areas where there is a particularly high level of concentration.

Raking wood ash into garden

You can also add the ash into your compost heap. This will help fertilise the whole compost heap ready for when you use it for planting. Just be sure that you use the compost for the right sort of plants. This can be added in at any time of the year. However, don’t add ash from coal. Not good. Ash from lump wood charcoal on the other hand is fine to use if you use that in your BBQ.

How good are the nutrients? 

The amount of nutrients in the ash from the fire will depend on the wood that you are burning. For example, hard wood ash (Oak) has more nutrients than soft wood (pine or fir). As with anything, you will need to strike a balance when thinking about the nutrients in the garden. 

Things to be aware of

It is best to dig in the ash over the winter months prior to sowing. This is because the ash, in some cases, can burn the plants. By getting it in the soil early, the nutrients are in the right place and there is little to no danger of them causing any damage

If club root is present in the garden, you can also use it to prevent and control it. However, you don’t want to raise the PH level in the soil too much as it will have a detrimental effect on your vegetables. You are looking for normal operating PH levels to be around 6.5 but we wouldn’t advise going anything over 7.5 as this will have a negative impact. 

Can I store the ash and use it later

Yes, of course. However, you must ensure that it is kept in a dry place away from any moisture. This is because as soon as it gets wet, the nutrients that you want to go into the soil will simply be washed away. If you have the space, try storing you ash in a water tight metal bin – in a garage or shed to prevent any moisture getting in. 

Other tips

Naturally, when you clean out your fire or bbq (if you use lump wood) you want to make sure than any large bits of wood that remain are removed. You can use a basic sieve to get these out. 


When dealing with the ash, it will contain small particules. We recommend, using a face mask if you can to prevent you breathing in any of the particles. This is especially important if you are sieving the ash to remove any large lumps.