I understand this is an old thread, still hopeful that someone would answer my question. I have a slightly raised garden bed 8 feet away from a mature maple tree. The first season, I grew veggies, herbs, and flowers with very good results. At the beginning of the second season (last year), I noticed that the bed had been completely invaded by the tree with dense roots everywhere. I cut the roots, refreshed the soil, and planted the same things. They did not grow well, all the nutrients being sucked up by the big tree. Now, I am looking for a barrier to isolate my garden bed from the smart tree. It has to cover the bottom and one side of the bed. Any suggestions would be greatly appreciated. BTW, I cannot move the garden bed to a different location. This is the only spot that I have.

organic black earth would contain triple mix I imagine. So I think you are good. If you feel you need some drainage, add some more peat moss. My mix is mostly the blackearth and about 2 bags of the manure. I sometimes add peat moss and sometimes I do add bone or blood meal but that won't be necessary with your high iron content. Just mix it in. You can start a compost box elsewhere and create your own compost to add to the soil later on.

When staining your planter, you probably ingested, by breathing in, vastly more xylene and or trichlorobenzene that you would through the food you'll get out of your planter. Once the stain is dry, the hazardous volatiles are mostly gone and whatever remains, you'll breathe in just by standing near it, especially if the stain is on the outside!

Yes, the plan does warrant boxes. They will be on a large slabbed patio that is very geometric in nature. Through careful placement and usage I can take advantage of the hard edges and angles already in place to create a nice sense of unity. I am a designer, I can nerd out about this stuff for hours ;) Also, I was looking for a whitewashed look as well, as some of the brick on the back wall of the house has an aged look with white flecks... it would be a nice tie in to the boxes and wouldn't create such an abrupt change. Though tension is always nice.