Why is coal ash no good for fertiliser?

Question

Wood ash is excellent fertiliser. As you'd expect, it contains exactly the minerals plants need. So how come coal ash is no good? It comes from the same source.

Coal originated as vegetable matter. It still contains the same elements. So why isn't it a useful fertiliser, like wood ash?

Coal originated as vegetable matter. It still contains the same elements. So why isn't coal ash a useful fertiliser, like wood ash?

Answer 1

Damm, thats a good question! To the guy above me, how can the oils still be in the coal ash? The coal is already spent..

Answer 2

Coal is a carbon based fuel and once spent contains no nutrients.
Wood ash that has obviously come from spent wood fires contains believe it or not, nutrients such as Potash which is beneficial to plants especially good to help and encourage flowering. These nutrients are taken in by the tree/bush whilst growing and are stored in the cells of the tree.

Answer 3

Great answer, Neera S. well thought out. As is always the case with vague questions like this.. A vague answer must follow. If you have Alkaline soil, wood ash is not appropriate. It will buffer pH even higher, which can be harmful to many plants. If your soil is acidic, it can be helpful. Ash is low in Nitrogen, so a high N source is likely needed in addition to the ash. The most important thing is.. KNOW YOUR SOIL before using ash. Test for pH and nutritional deficiency. Add nutrients that the soil needs, not just what you have available to you. Too much of certain nutrients can be toxic to plants and can be worse than having insufficient amounts of others. Have your soil tested. Then amend.

Answer 4

Coal contains oils that are not good for the plants or the soil.

Answer 5

Ashes really aren't good for plants because they contain salts.

Answer 6

its toxic.