Naturcycle talks often about the benefits of green roof media and the dangers of high organic matter in roof soils. Even as we educate landscape architects and contractors about what quality, consistent, soil-less media should be, we still see factors like cost or time driving bad choices.
Pictured below is what happens if you think topsoil or native soils can be an effective on-structure solution. Soils with high silt or clay content cannot succeed in the unique micro-climate of a roof setting. The heating and cooling extremes, the limited soil depth, the wind conditions, the exposure to sun, and even reflection from nearby buildings are just a short list of the many challenges in making a green roof work.
This photo was taken in late May 2019 in Central New York. You can clearly see this material is a loamy native soil hoisted onto a roof. The failures are already beginning and this installation is no more then a few weeks old. It has not been that warm or dry in the region this year, but you can see the soil cracking and segmenting already. If this is happening in May, what will it look like in July? The soil can not hold the moisture it needs. It is likely far too dense to support good plant growth. You can see significant yellowing in those sad tomato plants, indicating plant stress. If the plant is stressed this soon after planting, I would bet it does not last through the season.
Cutting corners or not researching the right options leads to failures like this. Lightweight aggregate, quality compost and the knowledge of the right materials for the right application are what Naturcycle and its engineered soil success is built on. I cannot imagine what the removal and replacement of the soil pictured here would cost rather than doing it right the first time. Contact Naturcycle today about your project or green roof needs. We are happy to offer insight, planning and resources, as well as logistics expertise to help reduce cost and maximize time. We know time and cost are important factors, but failure is not acceptable to our team at Naturcycle. We are in the business of success!