Urban gardening isn’t just about growing tomatoes in a small closet. It’s about understanding the complexity of soil microbes in unconventional spaces and utilizing new methods that make city gardening not only possible, but also incredibly rewarding.
Plants with healthy microbial communities in their root zones tend to grow more vigorously and are better equipped to withstand stressors such as drought, pests, and diseases. In urban environments where plants face challenges like air pollution, heat islands, and limited space, this microbial support system becomes even more crucial.
Urban soil faces unique challenges that rural farmland doesn’t necessarily encounter on a daily basis. You’re dealing with:
Start with Quality Organic Matter
Your soil microbes are essentially composting machines, but they need fuel. Add compost, aged manure, or leaf mold regularly. These organic materials provide the carbon and nutrients that feed your microbial community. In cities like Portland and Seattle, many neighborhoods now offer community composting programs—take advantage of them!
Test and Track Your Progress
Understanding your soil’s microbial health doesn’t have to be guesswork. Modern soil testing technology allows you to monitor microbial biomass and the fungal-to-bacterial ratio right from your balcony or rooftop garden. This data helps you understand whether your soil management practices are actually working.
Minimize Chemical Disruption
Synthetic pesticides and fertilizers can disrupt your carefully cultivated microbial community. Instead, focus on building soil biology through organic amendments and natural pest management strategies. Beneficial soil microbes perform fundamental functions such as nutrient cycling, breaking down crop residues, and stimulating plant growth.
A recent study reported by the NIH reveals an intriguing connection between gardening and human health that goes beyond fresh vegetables and exercise. It found that frequent exposure to environmental microbiota, especially through skin to soil contact, diversifies commensal microbiota, enhances immune modulation, and ultimately lowers the risk of immune-mediated diseases.
As more Americans embrace urban gardening & soil health practices, we’re seeing innovations that make microbial monitoring and management more accessible than ever. Whether you’re growing herbs on a fire escape in Brooklyn or maintaining raised beds in a Phoenix community garden, understanding and nurturing your soil’s microbial community will help you grow healthier plants while potentially benefiting your own well-being.
Zack Shier, Joseph Tree Service
Effects of Humate and Organic Based Soil Treatments on Urban Soil Characteristics
Zack Shier, Board Certified Master Arborist and Plant Health Care Manager at Joseph Tree Service, is utilizing microBIOMETER® in his study titled Effects of Humate and Organic Based Soil Treatments on Urban Soil Characteristics.
Introduction to the study. Urban soils have long plagued tree care providers with a difficult obstacle to tree health optimization. The very nature of how our urban soils come to be makes it quite challenging to diagnose the major issues with our soils, let alone correct those issues consistently, and with enough efficiency to make it affordable to clients.
When buildings or homes are built in our cities and towns, the natural layout and structure of soils is heavily modified, and often changed in erratic ways. Large holes are dug, bringing soil horizons meant for the deep areas, to the surface; mixing heavily with surface horizons. The top O and A soil horizons are often scraped clean to level surfaces, moving them or completely taking them away. Outside products, like “clean-fill” are often brought in, adding foreign soil or even rock (like quarry, limestone fill) into the surface soil area.
On top of this sub-par growing medium we’ve created, we also plant turf or put asphalt and concrete into most of the area. We then rake up and get rid of all organic litter and material, continually robbing the soil of the reincorporation of organic matter that forests are accustomed to. To add to the problem, urban trees are grown quickly using synthetic fertilizers on tree farms, and then dug up to be planted, cutting anywhere between 50-90% of their roots off, and often planted in different soil than they were grown in.
This entire predicament creates poor chemical, physical, and biological soil characteristics, resulting in poor urban tree growth, increased insect and disease populations, and high rates of nutrient deficiencies. (Read more)
