Rock flour is a natural product that can improve your garden's soil and introduce various minerals and trace elements beneficial to plants. However, you can find out in this article why it is not suitable for fertilizing hydrangeas.
Can I fertilize hydrangeas with rock dust?
Rock flour is obtained from volcanic rock. The minerals it contains cause a high pH value. Since hydrangeas require acidic soil, fertilizing the ornamental shrubs with rock dust is not suitable.
What is rock dust?
So-called rock flour, also known as primary rock flour, is anatural soil additive made from volcanic rock. It contains minerals such as calcium, iron and magnesium, but neither phosphorus, sodium or potassium, which are commonly found in fertilizers as these support plant growth. Rock dust is therefore not a fertilizer in the true sense, but it can be used to improve the soil in the garden.
Is rock dust good for hydrangeas?
Due to its alkaline properties, rock dust isnot suitable for hydrangeas Even the relatively acidic bas alt rock powder has a pH value that is too high for hydrangeas. Similar to the use of lime, which is also contained in small amounts in rock powder, soil that is too alkaline means that hydrangeas can no longer optimally absorb the nutrients from the soil.
Tip
These plants love rock powder
While it is not recommended for use on hydrangeas, rock dust is suitable for many other plants in the garden. Heavy eaters such as tomatoes are particularly happy about the extra portion of minerals and the deacidification of the soil.
