How and where to use biochar
When you are planting out into the garden / allotment you should apply biochar to the soil, in the root zone. Add 1 part of biochar to 9 parts of compost (10% application rate) and make sure it is charged up with nutrients before planting with it. Biochar can also be applied as a top dressing where it acts as an effective mulch. Some of this biochar will eventually be transported throughout your soil by worms.
Pricking Out & Growing On
When you prick out your seedlings into individual pots / trays, giving them a little bit of biochar will help establish a healthy root system. Use the same application rate of 10% as you would for all soil, just go a little lighter on the fertiliser you're using to charge the biochar. Too strong and you will burn the roots of the plant.
There is no need to add biochar to your potting mix when you are sowing seeds.
At the early stage of a plant's life, the roots can be damaged by a high concentration of nutrients, so this is why we don't recommend using biochar for very young plants.
Other ways to use biochar: Biochar compost
When you add biochar into the composting process from the start it dramatically increases the quality of the finished compost product. This is known as Co-Composting. Your compost will reach higher temperatures in a shorter space of time as the microbes find refuge inside the pores of the biochar causing them to multiply. More microbes mean faster composting! It also absorbs methane emissions making your compost produce less greenhouse gas.
But that isn’t the only benefit of using biochar in composting. Most people find the task of emptying their kitchen caddy into their garden compost bin unpleasant. To overcome this, every time you add to your kitchen caddy, also add some biochar. This will absorb most of the unpleasant smell as well as absorb the liquid.
Read our blog to find out more about how compost plays its role in helping combat climate change.