Originally appears in the Summer 2010 issue

Modern agribusiness has accustomed us to buy almost any fruit or vegetable whenever we want.  Finding bananas from Ecuador in the middle of winter is as natural as finding fresh seafood in the middle of the country.  The closest that many young people get to the origins of the food on their dinner table is at the local grocery store.  Being so far removed from agricultural operations, it is hard for them to truly appreciate the complex web of processes and relationships that brings food to their table.

By contrast, a sustainable food system encourages local production and distribution, and ensures that nutritious food is affordable and accessible to all. Further, it is a humane and just system that protects farmers and other workers, consumers and communities. Our food system is complex, woven with many interrelated parts, and best understood through systems thinking.  It is much easier for students to visualize and appreciate food systems when they have opportunities to study an actual system.

At Environmental Charter High School, we knew we needed a project that would help our students develop a more realistic view of the food system while teaching important concepts of sustainability, permaculture, and systems thinking.   The project we developed is a system using two buckets to grow food. It has provided us with a practical, hands-on learning opportunity that gets our students outside.  While our container gardens are much smaller than that of a traditional school food garden, they are large enough to provide an effective context for learning.

In this article, I will describe how to build this self-watering container system and suggest some related activities and experiments you can use with your students. While we worked with high school students, this system can easily be adapted for use with lower grades.

In our system, two buckets are stacked together. The inner top bucket holds the soil and the plant, while the outer bottom bucket holds the water. The water is delivered to the plant through a wicking system that draws the water up to the plant roots only when needed.  Much less water is needed than for a traditional garden – and very little is lost to evaporation. (Water is added to the bottom bucket occurs every 1-2 weeks through a tube.) With no weeding, it requires little effort to maintain.   It can be built quickly and economically with cheap or recycled materials. It is portable, does not take up a lot of space, and can be re-used year after year. And many people have found that container systems produce more vegetables than can be grown in comparable-sized spaces in traditional gardens.

Many types of vegetables, herbs or flowers can be grown in our bucket containers, but tomatoes grow especially well.  Your own choices will be dependent on your personal preferences, the season, your local climate and the length of time you can devote to this project. Whenever possible, allow students to choose what to plant, so that they will have more ownership over their project. Growing a salad or pizza garden with these container systems can be fun.  Obtain specific planting and harvesting time information for your area and avoid plants that are root intensive or like watermelons, don’t lend themselves to container gardening.  And to increase efficiency, we recommend planting seedlings rather than seeds.

Activities

Biology/Life Sciences: Initiate a class discussion about what makes up a community.  Suggest that the different plants in their containers represent a community, in much the same way that the class is a community. Each individual plant needs different amounts of water, organic nutrients, sun, and time to develop.  To have a healthy community in a container garden you need a diversity of plants that are fed with proper nutrients, water and sun. (The more bio-diverse an ecosystem is, the healthier it tends to be). The same concept holds true within your classroom.

Ask them to consider the growing conditions in their bucket containers or local food gardens or farms.  If the food grown in these local settings does not have the proper amount of nutrients, water, or sun or it is pumped full of chemicals, will they produce food?  If not, where will your food come from? (Food will have to be trucked in from outside the community.) What are the consequences? (Reduced productivity of the farmland causes social, psychological, and economic hardship for farmers, and the increased cost of food causes economic hardship for the community, whose money is no longer staying within and supporting that community.) Now zoom out to view the bigger picture. What can we do as a world population to make our food resources more sustainable? How can we keep our resources diverse and productive over time? What are the benefits of sustainable gardening and sustainable agriculture? What are the social, economic, and environmental consequences on a world level if we don’t move to sustainable agriculture?

Sciences

A:  The goal of the permaculture revolution was to create stable agricultural systems. (The term permaculture came from “permanent agriculture”, but has since been expanded to mean “permanent culture.”)  Among its key principles are the following: observe and interact with your surroundings; all energy can be captured; feedback is important (listen to your system); use your resources wisely; there is no waste in nature (nor should there be in our systems); use small, doable solutions; biodiversity is good; and everything should serve more than one purpose.

These principles apply equally to large agricultural lands and systems as small our self-watering containers.  Have your students apply permaculture principles before planting, during the growing period and after harvesting.  When using recycled materials to make their self-watering containers, make sure that everything serves more than one purpose. What other permaculture principles can be applied before planting? Have your students come up with creative answers.

B:  While the plant is growing, students should “listen to” their system—observing and interacting with their plants. Are the plants getting enough water? Students will have to monitor the water levels and make adjustments accordingly. There are intricate connections between the sun, the plant, the soil, insects, and humans. What are they? When you alter one, how does that affect your plant? What other permaculture principles are in place? For example, the energy from the sun is captured by the plant. Are you using your resources wisely, such as putting more into the system than you are getting out of it?

Systems Thinking

A:   All systems have inputs and outputs, and all systems need the support of other systems in order to operate. Our self-watering container system is an example of an open system: it demands inputs from other systems to sustain itself, but it also provides outputs. The plant – the fruit of our labor – provides us with oxygen to breathe and food to eat. What other outputs does our plant produce? Are these outputs now inputs for other systems? How do all of these inputs and outputs interrelate?

B:  All systems in our world nest within other systems. Take, for example, the buckets that we used for our self-watering container system. These buckets were originally used for a different system: the transportation and storage of food. What other systems brought your buckets to you? Typically these would include the transportation system, the agricultural system, the monetary system, and so on. As one can see, even just obtaining the two buckets involves a lot of systems. Have your students list all of the inputs the self-watering container system requires. There are the physical items needed to build the self-watering container (buckets, soil, fertilizer, etc.) plus the natural resources that the plant needs to live and grow (water, nutrients, carbon dioxide, sunlight). A concept map or flow chart is a great way to visualize all of the inputs our system needs.

Ethics  The ethical component of permaculture is the idea that we should utilize Earth’s resources in ways that are both wise and equitable. We should change the way we live in order to support each other. Not only does this protect the Earth, but it also develops stronger societies. Discuss with your class how you can use your self-watering container projects to help others. You could give your produce to families in need. You could host a farmer’s market to sell your produce and use the money raised for different projects. The possibilities are endless and the rewards are priceless. Sharing the harvest with others is an especially satisfying part of this project and is a perfect demonstration of permaculture ethics.

 

Science ExperimentsLaimon_1

 

After harvest, have your students design their own self-watering container system and decide what they would do differently the next time, based on feedback from their system (and with long-term sustainability in mind). What input/output changes to their system would they make? How could they make their system more efficient (i.e. Where did they get their inputs?  How can they decrease waste?)?  Consider the other, larger, systems that contribute to our system. How many different levels can they come up with? For example, “Have students think about how and where the buckets were made, what they were made from, who harvested the materials that made them, etc.

Have your students make recommendations that will be used by other students doing this project in successive years. For example, one permaculture principle is to produce no waste. Composting plant waste to return the nutrients to the soil is a sustainable way to provide needed soil nutrients. Reflecting another principle – using your resources wisely – students may also want to build a water catchment system that collects and uses water from the gutters of the school.

In addition to those discussed above, the self-watering container system offers several other potential connections to sustainability concepts and practices, such as the benefits of local, organic foods and the slow food movement. Some schools have also used their harvests for fundraising and philanthropy.

Using the self-watering containers to introduce the concepts of sustainability, permaculture, and systems thinking yields long-term benefits. Once students are empowered with this experience and knowledge, they will likely develop a world view that helps them to make better choices with the planet in mind. Our ultimate goal is that these future leaders will become more globally aware advocates for sustainability.

 

Making a Self-Watering Container System

Items needed:

  • Two recycled, food-grade five-gallon buckets for every 4 students in a class (You can often find free buckets at local restaurants or bakeries or via online services such as Craigslist. Do not use paint containers.)
  • One 16-ounce recycled yogurt container or plastic cup
  • One 17-inch bamboo stick or a similar length hollow tube or pipe about ½” in diameter
  • One bag of organic potting mix
  • One cup of dry organic fertilizer
  • Drill with 1/4-inch drill bit
  • Keyhole saw and/or a utility knife

Procedure:

  1. In the next few steps, you will find instructions for drilling or cutting the following holes in the bottom of one of the five-gallon buckets: one large hole for the 16-ounce container to sit in (which will act as the wicking chamber); one medium hole for the bamboo stick or tube (which will deliver water to the bottom reservoir bucket); and approximately twenty small holes for drainage.
  2. To determine how large of a hole to cut for the wicking chamber to sit in, you will need to find out the height of the water reservoir. To do this, put one of the five-gallon buckets into the other in front of a light source. On the outside of the outer bucket, mark the location of the bottom of the inside bucket, then measure the distance from the bottom of the outside bucket to this mark. Measure this same distance on your yogurt container or plastic cup, and measure the diameter of that container at this spot. Add 1/8 of an inch to this measurement and that will be the diameter of the large hole.
  3. Turn the inside (i.e. unmarked) five-gallon bucket upside down, and draw a circle in the center on the bottom of the bucket, with the diameter determined in step 2. Drill a series of 1/4-inch holes around the perimeter of this circle. Use a keyhole saw or utility knife to cut the hole out.
  4. Measure the diameter of your bamboo stick or tube. Add 1/8 of an inch to this measurement to give you the diameter of the medium hole. This hole should be near the outside edge of the inside bucket (the one you just cut the large hole in). Cut the hole the same way as above.
  5. Drill approximately twenty 1/4-inch holes in the remaining area of the bottom of this bucket. These will be drainage holes that will allow water to seep out of the soil (i.e. in addition to the ¼ inch hole).
  6. Up and down the sides of the yogurt container, drill 14-18 evenly-spaced ½” or ¾” holes. Take care not to cut open the side of the container, or put any holes in the bottom.  Once it is inserted into the bottom of the inner bucket and filled with potting mix, the yogurt container will act as the wicking chamber for the water.
  7. Next, drill an overflow hole into outer bucket (the five-gallon bucket without any holes) so that the inner bucket will not be sitting in water. Drill a 1/4-inch hole approximately 1/4 of an inch below the mark you made in step 2.
  8. Place the five-gallon bucket that is full of holes into the bucket with the overflow hole.
  9. Cut one end of your bamboo stick or tube at an angle and place the angled end into the medium hole at the bottom of the inside bucket and down into the water reservoir area of the outside bucket. The top of the stick or tube should be 2-3 inches above the top edge of the buckets. The angled end prevents the tube from clogging.
  10. Fill your yogurt container or cup with potting mix and place it into the large hole so that the bottom of the container is in the water reservoir area. The top of the container may stick up into the inside bucket but this is fine.
  11. Fill the inside five-gallon bucket with potting mix, compressing the mix along the way.
  12. Transplant your seedlings or plant your seeds in the center.
  13. Make a shallow, circular channel in the soil around the perimeter of the plant. Sprinkle a cup of dry, organic fertilizer into this trench.
  14. Pour water through the bamboo stick or tube into the reservoir chamber of the bottom bucket (you may want to use a funnel to make this process easier) until water begins to flow through the overflow hole.
  15. Place your self-watering container somewhere sunny (even if it is on pavement) and watch your plant grow!

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Sara Laimon is the coordinator of the Green Ambassador program of Environmental Charter High School in Lawndale, California.    To learn more about the program and the school, visit www.greenambassadors.org and www.echsonline.org.