Bioretention media is an important topic in the design world. As green infrastructure solutions gain acceptance, there is increased focus on finding the most effective media for on-site stormwater management. But there isn’t (yet) a lot of agreement on what the media consists of, and how to make it both functional for stormwater while being… More
Dr. Kelby Fite is a national leader in the use of biochar to improve tree health. Kelby is an Arboricultural Researcher at Bartlett Tree Laboratory in Charlotte, North Carolina — a 350 acre private arboretum, diagnostic laboratory, and exceptional applied research center. His specialties are root biology and urban soil renovation. Kelby has a PhD…. More
Most urban sites have some amount of mineral soil in place when the time comes to install plant material, yet these soils are often assumed – erroneously – to be unsuitable. Historically there have been two approaches to this situation. The default option is to ignore the problem, or make minor modifications such as digging… More
Humans have been managing plants for thousands of years – watering, saving seeds, protecting plants from herbivores. We began learning about horticulture initially through observation. Some of our observations were correct, such as which plants needed lots of sun and which could grow in the shade. Others, such as adding sugar to the soil for… More
We’ve all taken shelter under a tree’s canopy during a storm, grateful for its ability to intercept rain. You may not realize this, but rainwater that passes through tree canopies is modified both volumetrically and chemically in processes that have been relatively well studied in forests. That modification, which encompasses several different components, is what… More
In anticipation of the American Society of Landscape Architects tradeshow later this week, today we’re highlighting an iconic tree planting project using suspended pavement – including archival photos and original section details – that took place in Denver in the early 1980s: the 16th Street Mall. -LM Denver has long been a place of significance in the… More
Question: What does “non-point source pollution” mean? Answer: What’s the point of non-point? The point is clear once we realize we’re talking about pollution. Non-point source pollutants are water contaminants that don’t come from a pipe, well, construction site, or any other well-defined, specific source. They come from a diffuse source of contamination originating in… More
Today’s post, written by James Urban, FASLA, originally ran in 2011. But understanding soil organic matter – a sometimes mysterious-seeming property of healthy soil – remains a fundamental component of any discussion about planting trees for long-term success. -LM As a soils guy, I have a lot of discussions with clients and colleagues about the quantity… More
Q: I recently got into a conversation with someone who claimed soils are a renewable resource because the nutrients in them can be replaced with fertilizers. But I’ve heard that soil takes a really long time to form, so that to me makes it non-renewable. What’s your opinion? A: The idea that soil is renewable… More
A recent issue of the Ontario Association of Landscape Architects (OALA) magazine, Ground, contained a great discussion between nine professionals on the topic of soil. James Urban, FASLA, ISA, wrote to the magazine to add a few more comments to the piece – taking issue with the contention that what we plant in shouldn’t be… More
Last year, Jim Urban wrote a post for this blog entitled Against Mulch. The principle reasons he cited for his position were: 1) Mulch floats and can clog drains and releases “lots of phosphorus” as it breaks down, and 2) work by Gilman et al. that suggest that mulch does not reduce evapo-transpiration. We discussed… More
We love trees. We also love woodies. For those of you who have been reading this blog for a while, you will know that we promote large volumes of non-compacted, biologically active loam as essential for street tree health and longevity. There are other plants which require soil volume and need attention as well. Vines,… More
Soil. Stormwater. Sustainable Infrastructure.
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