Sustainable Gardening and Permaculture – the Key to Restoring Urban Land Vitality
When speaking about sustainability, regeneration of resources, and permanent agriculture, people often think of fields and farms. We often forget that cities also occupy large swathes of land, and their landscape plays an important role in our entire ecosystems. Limiting our efforts to making open-field agriculture sustainable would not only be short-sighted, but also overlook massive benefits for us and the environment.
We spoke with Caleb Gruber, Supertrends expert in permaculture and owner of a business specializing in landscape designs for urban properties, about the challenges of restoring the ecosystem in the urban environment. We complemented his ideas with a few tech innovations that could benefit consumers in creating and maintaining their own home green spots in a sustainable way.
Supertrends: What is permaculture and why is it important for us?
Caleb Gruber: Permaculture gives us a system of ethics and principles which we can use to guide our urban land use decisions. For example, conversion of irrigated turf grass to wildscape and food production can have enormous environmental benefits.
In order to restore vitality and stability to our urban land, we must consider re-wilding as much of it as possible. Truly wild landscapes are at the heart of ecological sustainability – they provide the buffer for everything that we do, and it is the sheer beauty of these wild areas that grounds us and reminds us of our role as a humble species of Planet Earth.
Permaculture gives us a toolbox and a language for harmonizing with the rhythm of nature, for becoming stewards and caretakers of Earth rather than just taking resources from it, and for creating a new urban ecology which all beings of the Earth can benefit. Just imagine what we could do with all the land if we applied permaculture as a solution.
A NASA-sponsored study estimated that between 40% and 55% of all urban development in the US, or roughly 40 million acres, is devoted to irrigating turf grass. By converting just 10% of this land area to wildlife refuge, using permaculture methods and indigenous plants that flourish based only on natural precipitation, an estimated 25 trillion gallons of irrigated water per year could be saved. If another 10% of that land were used for growing food, we could grow enough to feed two million people.
ST: What are the most important practices of urban sustainable gardening?
CG: The most important practices of sustainable gardening can be drawn from permaculture, and that is to use only organic methods for growing, i.e., eliminating the use of chemical fertilizers, pesticides, and herbicides. Only organic fertilizers should be used, such as manure and compost. The gardener should strive to keep their ecological loop as close as possible, meaning they should recycle nutrients and organic material back into their gardens by composting as much as possible and growing a sufficient amount of high carbon crops (a technique known as biointensive gardening). Also, it is very important to actually eat or use what you grow. Vegetable and fruit plants require a significant amount of water to grow, so it is important that we aren’t just growing food for “fun”, but with the intent of consuming all of it.
ST: Why is it important that city people practice sustainable gardening in their homes?
CG: Even by growing a small amount of your own food, you can greatly curb your carbon emissions. Food mileage has a significant carbon footprint. A tomato shipped from 1,000 miles away may have a carbon footprint of a few hundred pounds of CO2. By growing our own food, we also reconnect ourselves to the cycle of nature and gain a better appreciation for the process. We learn how to eat in season, and we learn how to preserve our food to make it last longer. Food security and food resilience depend on a diversified and stable food chain, and by growing food ourselves, we greatly increase our own resilience and the resilience of our local food system.
ST: What are the practical challenges urban people face in implementing permaculture principles and sustainable gardening?
CG: Space is always a concern in urban settings. Many people may have access only to a balcony, or perhaps not even that. Modern technology gives us tools for growing plants indoors, but without direct access to the Sun, they are energy-intensive. Cities and suburban areas often have rules, ordinances, or Homeowner Associations that can impose legislative limits on what people are allowed to do on their properties, or may require that a certain percentage of their yard be devoted to turfgrass. It is not uncommon for urban soils to be polluted or contaminated, preventing people from being able to grow edible food safely. All of these issues create roadblocks and limitations to implementing permaculture that can be difficult to overcome. However, consumers don’t need to convert their entire property into a farm to practice permaculture or sustainable gardening. The best way to start is to start small, and use the permaculture principle of “small and slow solutions”. Plant a tree, start a small vegetable bed, make a worm farm, support local businesses – all of these things are a great way to get started with permaculture.
ST: What is a wildscape, and why is it important for the ecosystem?
CG: A wildscape is a deliberately altered and maintained landscape with the sole purpose of providing habitat for wildlife and conservation of regionally endemic plant species. This differs from a true wilderness area, in that a wildscape is maintained by humans, and in that wildscapes are typically a form of restoration from the previously damaged landscape. Urban areas have sprawled into wildlife habitats, causing irreparable damage and strain on the survival of wildlife. Therefore, it is critically important that we cultivate our urban land with the intention of providing habitat for wildlife.
ST: What is the role of pollinators for the ecosystem, and what should city dwellers be doing to protect them?
CG: Roughly 90 percent of plant species on Earth require pollination by animals in order to reproduce. For nearly 250 million years, flowering plants have been co-evolving in symbiotic relationships with their particular pollinator species. For example, the tubular white flowers of the flowering desert yucca plants co-evolved with only a few species of night moths and bats.
Urbanization of wilderness areas drastically changes the biodiversity of local pollinator communities. When we talk about pollinator conservation, we cannot omit a discussion of rural agricultural land and its impact on pollinator biodiversity population. Because agricultural land has takes up a much larger amount of land than urban areas, it is actually in these rural regions that we see significantly lower populations of pollinator species. As it turns out, urban areas can act as oases and refuges for these threatened pollinator species to survive.
In 2015, Barack Obama issued a challenge to the urban conservation community to create a million new pollinator gardens in residential yards and business campuses.
ST: How can technology assist in implementing sustainable gardening in the city? Can you give us examples?
CG: One example of a sustainable garden technology is smart irrigation controllers. Most irrigation systems use timed controllers to water a landscape on a pre-set schedule. Modern smart irrigation controllers take this a step further by automatically up-regulating or down-regulating their water use by accessing the internet to predict the weather and rainfall amounts, and by using on-the-ground sensors to measure rainfall and soil moisture. The future of this technology will utilize artificial intelligence (AI) and more advanced sensors to integrate every measurable environmental factor, and cross-reference this information with botanical databases to determine the exact water needs of each individual plant in a landscape, thereby allowing plants to thrive on less water and not wasting a single drop of this precious resource.
Smart irrigation controllers could be connected to rainwater collection systems and prioritize the use of rainwater over tap water when the rain collection tanks are full.
There are also many technologies in the realm of hydroponics and aquaponics that can assist with increasing the sustainability of gardening in cities where it isn’t feasible to grow outdoors. Examples include LED grow lights, vertical hydroponic tower gardens, and growing systems incorporating fish (aquaponics). Composting technology has come a long way as well, and people can now purchase home-scale anaerobic digesters and biogas generators. Satellite technology could be used to determine which areas of a city might be best suited for conversion to wildscape or farmland.
ST: Should city people grow their own food? If yes, how and why?
CG: Without a doubt, everyone who lives in the city should be growing at least a small portion of their own food, and in particular, they should be growing things that they like to eat often. Growing our own food helps to curb carbon emissions from food mileage, and it also adds to the food security of the urban eco-region. But before starting out, it is important for people to do a bit of research and educate themselves on what techniques are appropriate for their region, so that they are using their natural resources most efficiently and effectively. There is an ever-increasing number of technologies for people living in city apartments to grow food indoors. Many companies have created hydroponic growing towers that can fit in a living room or balcony. Wall-mounted hydroponic systems exist, as well as small desktop grow lights.
ST: Can aquaponics and hydroponics technologies be used in an urban home setting? How and why?
CG: Yes, aquaponics and hydroponics can be a great alternative to traditional soil growing methods in urban settings, particularly when people have limited access to land. Aquaponics is a more sustainable approach than hydroponics due to the use of fish in the system. The fish, along with beneficial bacteria, provide all of the nutrient needs of the plants, and eliminate the need for synthetic nutrients. Hydroponics does have the advantage of being able to grow food in small spaces with just a small tank of water, such as grow towers like those of Lettuce Grow. One big advantage of using aquaponics or hydroponics indoors is that it is possible to grow food year-round, and if LED grow lights are used, electricity consumption can be minimized.
Curious to find out more about sustainable agriculture and technology? Check out our sustainability publications page for more information on the topic.
About Caleb Gruber
Caleb’s personal mission is to empower urban land owners to regenerate their land and use its inherent potential to create ecological habitat for wildlife and to grow healthy, organic food. Through his private design practice All Beings Ecoscapes LLC, Caleb creates holistic permaculture landscape designs for urban properties and works with clients to maximize the potential of their land and reconnect with the rhythm of nature. He has spent the last seven years studying and practicing sustainable farming and landscaping techniques, including permaculture design, ecological habitat design, organic gardening, hydroponics, and aquaponics. He also teaches sustainability topics at Montessori School of Denver. Caleb holds a Bachelor’s degree in Environmental Engineering from the University of Colorado at Boulder and a Permaculture Design Certificate from Koanga Permaculture Institute in New Zealand.