Wood ashes are very rich in mineral salts, they contain calcium, potash, silica, magnesium and phosphorus. They are a source of food for plants and cannot harm them because their assimilation is gentle.
Here is a list of 12 plants that enjoy wood ashes:
More generally, in the vegetable garden, ash is good for most vegetables. Roses also appreciate it, as well as flowers, small fruits, fruit trees and most perennials and ornamental shrubs.
How to use wood ash on plants?
However, this natural mineral fertilizer must be used sparingly: spread in excess, the ash unbalances the soil and disrupts the plant’s assimilation of the various minerals and trace elements. It should not exceed 100g per square meter per year, i.e. two good handfuls. It is also necessary to disperse the ash well, even to scratch the soil to promote its incorporation.
Always wait until the ash has cooled down before sieving it, because the large residues cannot decompose quickly enough and cannot be assimilated.
Spreading will be done directly at the foot of the fruit trees just below the crown.
For bedding, spread the ash on the surface and then lightly scratch it into the soil.
If you want to save the ash for use the following spring, sieve it and store it quickly in airtight bags for safe storage until it can be used.
Be careful, do not abuse the ashes at the foot of the heather soil plants because they contain mostly calcium which modifies the PH of the soil, making it alkaline and therefore very unfavorable to the cultivation of these plants which would then risk developing chlorosis.
Are ashes good for plants?
The center is a good fertilizer because it is mainly composed of calcium (between 20 and 50%). It also contains silica (14%), potassium (between 3 and 9%), magnesium (1 to 4%), phosphorus (0.5 to 2) and other trace elements.
It is a good amendment because :
- Calcium is important for the proper functioning of the clay-humic complex and therefore for soil fertility,
- Potash stimulates the development of roots, the extent of flowering and, consequently, the generosity of fruiting,
- Silica plays a role in the assimilation and metabolism of plants,
- Magnesium is the main constituent of chlorophyll,
- Phosphorus plays an essential role in photosynthesis.
However, the balance of a floor is delicate! It is therefore essential not to make a massive contribution, otherwise the chemical and biological composition of the soil will become unbalanced.
Concerning the quality of the ashes, use only ashes from untreated materials, without paint or glue, free of plastic or colored paper. This would pollute your garden and drastically reduce the sanitary quality of the crops in your garden. Also, never use mineral coal ash, which is very toxic. Finally, prefer fresh ash, of better quality.
Do wood ash repel slugs?
You can spread ash around recently planted vegetable seedlings or around plants prone to the voracity of gastropods.
It only takes a few centimeters and the ash, slightly caustic, hinders their progress. But it must be renewed very regularly. Indeed, dew and rain make it totally ineffective, and we end up using too large quantities. It can be useful in a punctual way but it is not the best way to protect oneself from slugs and snails.
Can I add wood ash to my compost?
You can compost the ash, but only in limited quantities. However, because of its fine texture and high limestone content, it tends to hinder the proper aeration of the compost and slow down the bacterial activity, and therefore, the proper decomposition of the elements. Asphyxiation is all the more important in compacted and moist composts. Therefore, limit the amount to a handful from time to time.
When should I add wood ash to my garden?
The ideal time to use the ashes in the garden is the end of winter, in March or even April. Indeed, the potash contained in the ash is soluble and easily leached by winter rains. However, it is safe to do so earlier.
When spreading the ash, be careful not to do it on bare ground, otherwise you will quickly observe a beating phenomenon: the ash forms a crust that slows down the circulation of air and water and makes the environment asphyxiating. This is harmful to biological life and plant growth. Instead, spread the ash over a mulch.
To sum up, wood ashes, which are very rich in mineral salts, are a very good source of food for most plants in the vegetable garden. Their assimilation is gentle, therefore without risk!
Please note that acidophilic plants (called “heather earth”) do not tolerate ashes.