When most people hear “no-soil gardening,” they immediately think of hydroponics. Yet that is only one of several ways that gardens can be grown without the use of soil. No-soil gardening (or soil-less gardening) is used throughout the world to grow many things. From the American space program at NASA, to the basement tomato aficionado, soil-less gardening has become extremely popular worldwide.
Many gardeners have found that not only does it allow year-round growing in most situations, but it also allows the grower complete control over nearly every aspect of the growth process. Scientists use it to test plant strains, amateurs use it to produce better, healthier, more productive plants, and commercial gardeners use it to grow tastier, more consistent crops.
The most well-known of the no-soil gardening techniques, hydroponics is the growing of plants in water, bypassing soil altogether. For most amateur gardeners, this is one of the easier ways to grow, as it requires only moderate amounts of equipment and a little knowledge to do well.
The process is relatively simple: the plants are suspended in a medium (clay tablets, coconut fibers, or any of a number of media used to support the plant by its roots) and flowing or stationary water is kept underneath. The water is dosed with nutrients and light is supplied by sun or artificial means.
This is not necessarily a growing system apart from other soil-less methods, but is instead an extension for them. Fathered by Dr. Luther W. Thomas in the 1980s, bioponics became a scientific way to analyze the nutritional needs of plants and supply that nutrition in a more biologically active way. It is used in most types of no-soil gardening including hydroponics, aquaponics, and others.
Dr. Thomas’ research and life work has inspired thousands of others to formulate nutritive mixes for specific growing needs around the world. His own formulas are still produced in a family-owned business called Cornucopia. Thomas died in 2002.
Another well-known soil-less gardening technique, aquaponics is similar to hydroponics in that it focuses on the delivery of water and nutrients. The chief difference is that in hydroponics, water and nutrients are only used to foster plant growth. In aquaponics, the focus is on creating a closed-loop system, with the water itself also providing for forms of life outside of the plant crops being grown.
Most aquaponics systems include fish and other aquatic creatures, which provide nutrients and another productive food source for the garden. NASA has particularly focused on aquaponics as a possible stable, long-term food option for interplanetary travel and colonization.
Another no soil gardening method is aeroponics. A version of hydroponic gardening, but aeroponics focuses on the oxygen delivered to the root system. Instead of being grown in a water medium, a mist delivers the nutrients and water to the root system based on a timer.
Primarily the growing medium is oxygen, allowing quick growth of plants with oxygenated root systems. A benefit of aeroponic gardening, beyond quick growth, is water conservation.
There are many aeroponic growing systems with the simplest being an AeroGarden for home gardeners. These are small countertop growers for indoors, even a kitchen counter. Larger aeroponic systems can grow many types of vegetables.
Check out the video below to see no soil gardening in action: From rooftop to table top from CNN:
A term coined by Dr. Brett Roe, vermiponics is the combination of vermiculture (the husbandry of worms for composting and garden use) and gardening techniques to create a nearly closed-loop system for the growing of edibles.
The system works by using worms to quickly compost organic wastes (table scraps, inedibles, leftovers) and turning the resulting super-compost into a liquid nutrient for use in hydroponics or aquaponics systems. Aquaponics is preferred, as excess worms can be fed to the fish as another food source.
While still very new, the landmark paper produced in Australia by Roe and others has begun a new trend of discussion in soil-less gardening options.
Want to learn more about no soil gardening?
Check out these helpful websites:
Simple Home Hydroponics [PDF] from Northern Territory of Australia
Aquaponics from NASA
Rooftop Gardens and Vermiponics [PDF] from Rural Industries Research and Development Corporation in Australia