Hello I am an amateur gardener and my narrow yard is nothing more than a sand bar.. and to make matters more interesting… on it’s 14foot width there is a 6foot difference from one side to the othe as I am on the side of a hill. I put black earth, compost and mulch yearly and it all seems to vanish to middle earth… I have heard about biochar and I have been trying to figure out it’s it is viable for a garden that mostly is struggling perennials and shrubs.. how to use it… ANY information would be helpful.
Thanks for contacting us. The first issue is that you are dealing with a significant slope. That means that all those amendments really are vanishing … they are being washed away. Please have a look at our response to a previous inquirer regarding gardening on a hillside, here.
With respect to biochar, the research is ongoing. There are positive results in some agricultural crop growing projects; not so much for home gardeners. In part, that’s because it’s pretty complicated science and also complicated production.
A fact sheet prepared by Linda Chalker-Scott, Washington State University Puyallup Research and Extension Center can be found here. Another, from a scientist at Oregon State University, here. And from Arizona, this.
Closer to home, a professor at University of Waterloo conducted a 3-year study on the effects of biochar, ending in 2019. She has spoken about it at conferences and has prepared a factsheet which was published only 2 days ago! You can find it here.
At this point, it may be promising for large scale agriculture but the research is still ongoing. Meanwhile, in home gardens like yours, good compost can accomplish excellent results. And in your case, the first important step is to manage that slope.