The Use of Black Cinder in your Garden
Mix the native clay with half black cinder to aerate and “loosen” the mix.
Like other volcanic rock, black lava cinders have lots of pores resulting from expanding gasses when the stones are formed. These pores provide the perfect habitat for beneficial microbes to grow. Cinders are dense and will not float providing a more stable medium for growing plants.
For heavier, thicker soils the ratio should be about 60:40, adding more black cinders for better soil aeration, micro-organism retention and root development and increasing the soil’s drainage capacity.
This mixture is a blend of black cinders and soil. Black cinders are crushed volcanic rocks formed during the depressurization and cooling process of a volcanic eruption that are harvested from cinder cones. Their cavities are bubble-like, and are called vesicles. We recommend the black cinders for garden soil mixes
Adding black cinders to your soil yields a product called “Black Cinder Soil”. Depending on your needs and the density of your soil, the ratio of soil to black cinders can vary. Some gardeners use a mix that’s half cinder and half soil, and others increase the ratio to 60:40 when their soil is more “clay-like”, adding more black cinders for better soil aeration, micro-organism retention and root development as increasing the soil’s drainage capacity.
While quality topsoil contains organic matter that’s essential for plant growth, adding cinder to the mix can significantly improve its nutrient-retention. The vesicles and amorphous minerals, like allophone and imogolite, found on the cinder are notable for adsorbing organic matter, which is necessary for plant growth.