Hydroponics for the indoor gardener
by Robert Paul Hudson, EDN
If you have the winter blues and are longing for the beginning of the spring gardening season, consider hydroponic gardening. Hydroponics is the science of growing plants without soil and brings gardening indoors for anyone regardless of space or resource limitations. Instead of soil, an inert growing medium is used in combination with a nutrient rich system supplied directly to the roots, and either artificial light or sunlight if it is sufficient. Hydroponics systems on average use 10% of the water that traditional growing methods use, can be grown without the use of pesticides in a more sterile environment, and in some cases grown without seasonal interruption.
“Hydroponics lends itself to simplicity. The basics make it simple enough for anyone,” and goes on to say, “tomatoes, salad greens, and herbs are the most common plants for the beginner.”
Imagine being able to harvest fresh vegetables year round.
“Plants such as lettuce can be harvested continually year round if you are providing the right conditions,” according to Kelly Caudell of Corvallis Hydroponics.
There are two types of hydroponic methods to consider: static solution and continuous solution.
Using static solution, plants are grown in containers of nutrient solution and water in something as simple as a glass mason jar and aeration to the solution is provided with an aquarium air pump and airstone. A hole is cut in the lid of the container for the plant to grow through. Without a lid, rockwool may be used to keep the plant firmly in place and upright. If the container is clear, it should be covered with something such as foil, butcher paper, or black plastic to block light that would create algae growth inside the container. Only the plant growth above the nutrient plant reservoir needs to come in contact with light. The nutrient and water solution is changed according to a pre-determined schedule or more accurately indicated by an electrical conductivity meter.
Continuous flow is when the solution is constantly flowing through the roots in an automated circulation system. The constant flow naturally carries oxygen to the roots and can be easily regulated for temperature and nutrients. These types of systems are typically used in larger scale growing operations.
Some plants will grow better with their roots in a medium rather than suspended in a liquid solution. Growing mediums include rockwool, which is made from molten rock and spun into filament fibers, expanded clay pellets, coco peat which is the fiber from coconut shells, perlite which is made from volcanic rock, pumice which is also from volcanic rock, and vermiculite which is a super-heated mineral. All of these mediums have various pros and cons, but all have excellent cation exchange capacity – the ability to attract nutrient ions and hold them for plant uptake. They are porous and absorb the nutrient solution in either static or continuous solution systems.
Because of its simplicity, a static solution is typically more cost effective. Continuous flow will offer faster growth, blooms and higher harvest yields.
“The most critical thing to consider is light and to have the appropriate light for the plant species and the amount of area being covered,” says Caudell. “I recommend fluorescent lights for a beginner and small scale projects”.
High intensity lighting may be provided by metal halide and HID lighting that run on computerized electronic ballasts which are much more costly.
Caudell went on to say, “a good start up system including lights for two to four square feet of coverage could cost as little as $200.00.”
Virtually any plant can be grown hydroponically, whether it is fruits and vegetables, herbs, or houseplants.
“The only thing I have yet to see is root vegetables like carrots or potatoes,“ laughed Caudell, but added “it could be done with a deep enough container and some experimentation”.
Shea said, “there is more of an interest now in local grown produce, and nothing is more local than growing it yourself.” It is a hobby for people of all backgrounds and ages, and interest in the hobby is GROWING!
Emerald Valley Gardens
88680 McVay Hwy
Eugene, OR 97405
5490 SW Philomath
Corvallis, OR 97333