Soilless growing seems like a gardening oxymoron but it is the basis of hydroponic and aquaponic gardening. This type of gardening has been in use for thousands of years, from the Hanging Gardens of Babylon to the Floating Gardens of China to modern-day commercial or home gardens.
William F. Gericke, a plant physiologist at the University of California, ignited the recent revival of this ancient gardening technique during his tenure at the college during the early 20th century. He was a pioneer in hydroponic gardening and is credited with coining the term “hydroponics” which translates to “water works.” His skeptics were converted when he introduced them to a 25’ high tomato vine grown with just water and nutrients!
Since Gericke’s time, the science of hydroponics has advanced and been accepted by both commercial and home growers.
Basics of Hydroponics
Plants need nutrients, light, and water to survive. Most derive the former from soil, although in hydroponic systems water is the medium in which plants grow. The addition of nutrients mixed into the water allows plants to uptake these nutrients and light is often provided in an artificial form as many home hydroponic gardens are raised indoors.
Aquaponics introduces another loop into this system where fish are raised in tanks and their waste is incorporated into the fertilizing system. This type of farming is more involved than what many home gardeners have space or time for, but is seeing some industry growth for farmers that are land-strapped.
In its simplest form, a home hydroponic system consists of a container, a growing medium such as perlite or sand protects the roots, water, and nutrients. Many aquatic plants in nature have leaves that rest of the water surface and stems that extend downward into the mud, some plants grown in a hydroponic system will need some type of vertical support. Low growing plants such as greens do not need this support. This growing medium also protects the roots from light exposure and temperature fluctuations that may be detrimental. Excessive temperatures can stress the plant root.
Growing containers may be recycled pots or bottles depending upon the size of the plants being grown. Glass, ceramic, or plastic pots are preferred since they won’t rust and contaminate the system.
Grow lights may be necessary for the plants to photosynthesize and thrive since most hydroponic systems are set up indoors with insufficient exposure to natural lighting. Of course, a hydroponic gardener can use sunlight to power the plants and is a viable option. Like any gardening, the options are endless and revolve more around the gardener’s time and desire to undertake this type of growing. Grow lights recreate natural sunlight, emitting specific spectra of light that plants can use.
Water and nutrients round out the final items for the system. The nice thing for water is that it can be recycled from the system and reused versus lost to runoff or evaporation in an outdoor setting. A blend of macro- and micro-nutrients need to be added to the system since that is what is lost without soil.
Commercially available kits make home hydroponics easy to undertake. These kits may be small just for growing a fresh supply of greens or more involved for growing tomatoes, peppers and other crops. These larger systems might also need to be setup in a greenhouse or garage that won’t be ruined by water spillage.
Instead of an irrigation timer turning on and off for watering, many hydroponic gardeners use a timer to pump premixed nutrients into a reservoir that are then distributed to the growing containers. Piping is necessary in these cases to distribute the water and nutrients to the plants, but again, depending upon the size of the system, may be a simple solution of mixing nutrients into a watering can for adding to the pots. Piping may be made from PVC tubing or drip system tubing and connectors to deliver water directly to each plant. Submersible pumps, like those used in a pond, also may be incorporated to evenly distribute water and nutrients to the plants.
Some hydroponic systems incorporate an air pump which oxygenates the water and provides some circulation.
Many nurseries, home-and-garden centers, or online garden supply shops provide hydroponic kits that are ready to go. For the DIY gardener, there are a wealth of systems online that can be constructed to meet the complexity of their design. In the old days, hydroponic systems focused on the just the practical nature of growing plants, but today designers have also incorporated artistic or visually-pleasing systems that match any home décor.
Care and Maintenance
Like a normal garden, hydroponic gardening takes some care, maintenance and vigilance. Checking for leaks or plugs in the watering system is critical, as well as keeping a clean space that is disease and pest free. Outdoors its pulling weeds, but indoors it may be watching out for mold or mildew or insect infestations. Home hydroponic growing isn’t worry-free but offers an alternative solution to home gardeners that may have limited growing space, the desire to produce some basic greens, or wish to participate in a different method of gardening.