CO-Horts

Hydroponic Gardening

Posted by: Andie Wommack, Douglas County Extension

Our growing season in Colorado leaves something to be desired, especially by those of us who have transplanted from other areas of the country. Coming from the Idaho Palouse, I am used to a longer growing season, better soil, and more moisture than we get here along the Front Range. One of the solutions to increasing the potential for food production is greenhouse gardening. Greenhouse gardening extends our growing season and greatly improves our growing conditions. Greenhouses also help protect against some of the environmental factors that can adversely affect our plants like wind, hail, or late season frosts.

 

One particular method of greenhouse growing I would like to talk about is hydroponics, aquaculture and aquaponics. Hydroponics is the raising of plants without soil. Nutrients are added to the water which replicates the nutrients present in soil. Aquaponics is the mixture of hydroponics and aquaculture so the fish water is used to feed the plants. And finally, aquaculture is the raising of fish. If you are growing plants hydroponically you need to ensure that your water solution contains all of the essential plant nutrients since there is no soil to provide these nutrients for the plants: Macro Nutrients: nitrogen, phosphorus, potassium; Secondary Nutrients: calcium, magnesium; Trace Elements: iron, manganese, boron, zinc, copper, and molybdenum. The grower is responsible for balancing all chemical and physical conditions surrounding the roots of your plants. Since the grower has total control over the environment in which their plants are growing, the production capacity can be maximized. Another way to maximize efficiency and production can be done with the use of climate controlling technology.

Greenhouses, regardless of their complexity, all help control the climate of the growing area. Hoop houses help increase temperatures to extend the growing season. If you are interested in a hydroponic system, a greenhouse with heating would be recommended because you are dealing with water flow. A frozen system can not only kill your plants, but it can also severely damage your system. If you do not want to invest in a heating system, you would have to shut down production when the risk of heavy frost and low temperatures come around.

Hydroponic systems are closed systems that recirculate water throughout the system continuously. There are a variety of growing medias that can be used in a hydroponic system such as expanded clay, rockwool, or gravel. However, when growing hydroponically, water is the most important component. Maintaining water quality, pH, and nutrient availability will greatly affect the production and health of the plants being grown in the system. Depending on the type and size of your system, water should be changed or added to on a weekly basis. If you are utilizing an aquaculture system (combing fish production with plant production), one of the main things you will want to monitor is the ammonia levels in the water. Adding water weekly to these systems help lower these levels. You will also lose water because the plants are utilizing water to complete the process of photosynthesis. In a temperature controlled environment, it will also be warm enough to have potentially significant water loss to evaporation. Water levels not only affect the growing environment for your fish and plants, it can also affect your system. A hydroponic, aquaculture, or aquaponics system all rely on at least one pump to circulate water throughout the system. If the water levels get too low, you run the risk of burning up your pump or damaging other equipment used in the system. 

Hydroponics and aquaponics can be a great way to increase your production capacity and extend the growing season here in Colorado. Initial startup costs are quite a bit higher than traditional gardening methods, but the return you get in being able to grow your own food all year long can help recoup those costs.