There are a lot of plants that can be propagated by placing a cutting into water so that roots will form. There are also a few plants that can live in water indefinitely as long as they are provided with nutrients. I have five or six water-filled vases that are spilling pothos, the oldest of them being grown in water for the last five years.

Of course, regular old tap water doesn’t contain the necessary nutrients for them to survive, so I add a few drops of liquid fertilizer when I refresh the water. Not every plant can grow in just a container of water, and many will experience root rot or wilting, yellowing and stunted growth due to the plants inability to access oxygen.

When speaking of hydroponic gardening, it is a lot more involved than just a few cuttings in a vase of water. Hydroponic gardening is a centuries-old process said to have been used to create the hanging gardens of Babylon, by ancient Aztecs for crop production, and as a growing technique for China’s floating gardens. The science of hydroponics used today is due to the experimentation of Dr. William Frederick Gericke at the University of California in the 1930s, earning him the moniker, “father of modern hydroponics.”

In traditional gardening, mineral nutrients are held by soil particles and the soil provides an anchor for the plant. In hydroponic gardening, a substrate replaces the soil which is used to anchor the plant. Since the substrate does not contain nutrients, they are added to the water.

Common substrates that are used in hydroponic gardening are coarse sand or gravel that has been washed thoroughly to remove impurities, and perlite or coarse vermiculite, which are both sterile and uniform, making them the preferred choices. The substrate is capable of supporting the root system, holds moisture and nutrients, allows aeration of the roots and has good drainage qualities.

The ability to grow hydroponics relies on the same basic requirements as soil-grown plants; adequate water, light, nutrients and warmth that suit the species of plant being grown.

The light required for the plant is based on the needs of the plant when grown traditionally. Since hydroponics are generally grown indoors, artificial light, such as grow lights, are used to replace direct sunlight. Fruiting plants, such as tomatoes, that require full sun to grow, need 10 to 12 hours of light, while foliage or ornamental plants require less, making them more adaptable to indoor growth.

Temperature must also be maintained to create an ideal growing environment for the plant. For warm-season plants, daytime temperatures should be kept between 70–80 degrees and between 60–70 degrees at night. Cool-season plants like their temperatures to be kept between 60–70 degrees during the day and 50–60 degrees at night. Temperatures that rise above or fall below these ranges will result in slow growth.

Water and nutrients go hand-in-hand, as the nutrients are added to the water. The key factor in successfully growing hydroponics is the nutrient solution. Water soluble minerals are made available to the plant roots in a complete and balanced solution. Pre-mixed solutions are available, or you can mix your own for a more precise nutrient combination for specific plants.

There are a few simple hydroponic systems that are good for beginners. A non-recycling system is simply a well-drained container filled with a substrate that, when watered, the nutrient solution drains away and is lost. A more economical option is to catch the nutrient solution and reuse it for subsequent waterings. Because the water drains through the substrate, watering may be necessary up to three times a day to keep roots from drying out.

Larger-scale recycling methods involve using a container that has a hose leading into it and a catch receptacle fitted with a submersible pump that is used to recycle the water back through the plant container. The container is tilted so the solution drains away and back into the catch receptacle.

Hydroponic gardening allows for plants to be grown indoors year-round if you are willing to put in the time and commitment into the process. Until next week, happy gardening.

— Irland, a member of the Limestone County Master Gardeners, can be reached at kippirland@hotmail.com. Visit https://mg.aces.edu/limestone for more information on the Limestone County Master Gardeners.