Can You Use BBQ Ash on the Garden

A timely question for the summer was raised by a reader. Can you use the ash from barbecues on the garden? With one small reservation, a resounding yes.

Summertime Barbecues – Producing Ash

Hi John
Thanks for the newsletter – don’t know what I would do without it.
A question for you – is BBQ ash any good for the allotment ??
Regards
Mike Lenihan

BBQ ash is basically wood ash so well worth saving and using. Wood ash is a rich natural source of potash. Any unburned charcoal will break down in the soil and adds carbon, so benefiting a little. There is a fashion for using charcoal and biochar as a soil additive, usually quoting the benefits of Terra Preta in the Amazon.

Sadly there’s far more hype, often from those selling the product, than scientific fact so at best the jury is still out on the additional benefits of using charcoal and biochar in the garden soil.

Bones Add Value

Usually the barbecue has finished cooking way before the charcoal has finished burning.
Assuming it’s the standard carnivore meat-feast BBQ, you can add to the value of the ash by popping the bones on the charcoal at the end. If they burn away the ash will be richer for it.

Even the bones that aren’t burned to ash will add value to the soil but they can take a few years to disappear completely. You can speed the process by banging them with a lump hammer – sort of make your own bonemeal fertiliser Any bits of meat or fat adhering to the bones will have burned away so avoiding problems of smell and rats etc. being attracted.

Natural Charcoal – ideally local and sustainable

Warning!

One final point – charcoal comes in two types. Lumpwood charcoal which is purely made of wood that has been turned into charcoal and charcoal briquettes. There may be a problem with briquettes. Apparently some briquettes in the USA contain coal dust which means they’ll add minute amounts of coal ash to the soil.

Personally I’m not concerned about that in the slightest but undoubtedly someone will find a hysterical article on the web shouting that coal ash is more deadly than waste from a nuclear reactor!

Charcoal Briquettes – Regular shaped bricks

Most briquettes, in the UK at least, just contain sawdust and woodchips which are roasted in kilns and shaped. Additives such as cornstarch are then used as a binding agent so they don’t fall apart.

Preferably you should use a good quality local charcoal. Because this will be sustainable and 100% natural and not contain anything that possibly isn’t good for us. As with much in life, you pays your money and makes your choice.