While there are many advantages to gardening in a container, there are a few drawbacks as well. Perhaps the biggest challenge in container gardening is that more frequent watering is required. Vegetables, in particular, need consistent levels of water for optimum growth and production of fruits. The limited size of pots, the porosity of some containers, and increased exposure to wind can dry out the potting medium sometimes causing a need for watering more than once a day.
There are a few good ways to overcome this problem. Drip watering systems work well but can be difficult to install and can also be expensive if many large containers are involved. Another solution is to water by a method called “wicking.” Using this system water travels from a well up a nylon rope and across the container underneath the soil by capillary action. If you have ever accidentally left a corner of a dish towel in a sink filled with water and found a puddle of water on your counter or floor, you have experienced capillary action at work.
A simple container garden system can be made using plastic gallon jugs, 1” pvc pipe, 1” pvc pipe caps, and ½” nylon rope. The only tools needed are a saw to cup the pvc pipe and a utility knife to cut the top rim off the milk jug and to open holes near the top of the jug for the nylon rope to emerge. For a 2’x4’ container bed, two units are needed. The length of the pipe needed will depend on the depth of the bed. It is best to set the bottom of the unit on the base of the bed. Because the gallon jug must be completely covered with the potting medium to prevent light from entering (to prevent algae growth), the pvc pipe should be long enough to extend several inches above the top of the soil to facilitate adding water to the jug. For a bed that is about 12” deep, a 14- 16” piece of pipe will work well. About 5’ of rope will be needed for each unit in a 2’x4’ bed. The pictures provided show a completed unit and several beds with this system installed. (Note that the rope must be completely underneath the soil to prevent water loss. Since the water is needed by the roots, a depth of 2-3” works well.) Once the system is installed, water can be added through the top of the pipes using a garden hose as needed.
There are many advantages to using this type of system. Beds watered by wicking use about 50-75% less water because the watering is more efficient. Because there is no run-off, fertilizers won’t be leached out of the potting medium, making them available to the plants. There are fewer opportunistic weeds because the water travels from the bottom up and the surface of the potting medium has less water. This system also lessens the possibility of splash-back and reduces the occurrence of disease causing molds and mildews. Finally, it is inexpensive and easy to use!
Submitted by: Roz M., MG since 2015