LBHS: Sprinkler Conversion

Right up there with weeding and deadheading, irrigation maintenance is one of those garden jobs that never really goes away. The task of replacing sprinkler heads, broken emitters, and stretches of punctured drip line is both urgent and important and the problem pops up more frequently than anyone is happy with.

Often times, students (and maybe just people in general) are intimidated by these tasks and are quick to either pass the problem off, or ignore the problem completely. Perhaps for fear of getting wet, the average student is not interested in fixing irrigation, go figure.

However, it is an important skill for at least one student in the garden to know, so, in the following post I have outlined a lesson plan about sprinkler conversion. My logic is that if the students can build the irrigation system, they will know when something is wrong with it. After problem diagnosis, I can then teach the skills they need to fix the specific issue.

Workshop Details:
2 day activity- total 2 hours (30 min. discussion and 90 min activity)

Workshop Goals:
Teach students the importance of water conservation in addition to practical irrigation repair skills.

Required Materials:
-measuring tape
-graph paper
-pruning shears
-* 1/2" x 3/4" bushing
-* 3/4" elbow joint
-* 3/4" 15PSI pressure regulator
-* 1/2" compression tube adapter w/ 3/4" pipe thread
-** 1/2" poly-tubing
-***appropriate joints and end caps for poly-tubing

*you will need 1 part for each sprinkler head that you are removing
** poly-tubing is usually sold in 50 or 100 ft lengths (purchase after measurements are made on day 1 of activity)
*** poly tubing joints are either T-joints, elbow joints, or couplings (purchase after garden layout is determined on day 1)

In this two day activity, I spend the first 15 minutes talking about why it is important to conserve water and where the water comes from. The second half of the discussion I gave an overview of the project and explained the role of the students  in the plan. Then we got to work.

Background information:
What is groundwater, and where does it come from?

The soil holds water in the spaces between grains of sand, clay, and gravel. Where the water fills up all the available space between the soil particles, we say the ground is saturated. We use wells and pumps to tap into this saturated layer, and if we pump the water out faster than the well is being replenished, the groundwater supply shrinks.

Over time, the ground that was once saturated becomes dry and collapses under the weight of the soil above it. As you can see in this famous picture of the San Joaquin Valley, CA, the ground has shrunk almost 60 feet since 1925. Once this ground has collapsed, it cannot be put back. As a result, the maximum amount of water that the soil can hold decreases and there is less water available for the future.

Why do we need to conserve water?

We need to conserve water, so that we can continue to grow crops in the future. Increasing our collective water use efficiency, both in the field and in our homes, is an easy way to reduce waste and preserve our future.

So, who is excited to switch our wasteful sprinklers to a more water efficient drip system now!

Activity Instructions:

As I mentioned earlier, The activity is broken into two separate days. The first day, students will measure sections of the garden that will be maintained by drip irrigation and dig shallow trenches where the poly-tubing will be laid. In addition to recording the length of the trenches, the students will determine the correct number of T-joints, elbows, and couplings that need to be purchased.

As an instructor, you should give the majority of the students their digging instructions first so that you can spend your time making sure that the measuring team is successful. Make sure that the students systematically stack the piles of dirt onto one side of the trench. This will ensure that the soil can systematically be put back once the poly-tubing is laid in the trenches.While most of the students are occupied, assign a group of 3 students to measure the length of the areas where poly-tubing will be laid. Have one of the students record the lengths on a piece of graph paper. I suggest drawing the irrigation plan on the graph paper. This will make the objective more clear for the students. Finally, allow the students to tell you which joints are required to connect the different limbs of the irrigation system.

On the second day, have the students finish digging the trenches, if they have not already done so. After the trenches are completed, break the students up into 4  groups. One group will layout the poly-tubing and cut the pipe using a pair of pruning shears, while another group will connect the poly-tubing using the appropriate joints. You will need another group to start filling in the trenches where the tubing has already been laid. Finally, you will need to assign the last group to rig the sprinkler head up like shown in the picture adjacent to the "Required Materials" section of this post.

I suggest keeping a close eye on the group that is assigned to convert the sprinkler head as it is likely they will be the quickest with their questions. In my retrofit, some of the sprinklers were connected to a 1/2" riser instead of the 3/4" pipe depicted in the required materials picture. As a result we had to insert a 1/2" x 3/4" bushing in between the sprinkler riser and the elbow joint to make the rest of the parts fit on top of the riser.

Please leave comments if you have any questions! Good luck and have fun!

LBHS: Companion Planting and Seedling Starting

Hello again, today's post continues the former by detailing another workshop I developed for the students at Luther Burbank High School. As mentioned in the title, this post is about companion planting and seedling starting.

Workshop Details:

30 minutes (10 minute discussion, 20 minute activity)

Workshop Goals:
Teach students how to start plants in a seedling container. Help students gain an appreciation for the complex relationships that exist between plants in a garden.

Required Materials:
- 6-cell seedling containers (1 per student)
- Potting mix
- Perlite
- Seeds (suggestions for varieties listed below)
- Spray bottles
- Permanent Marker
- Masking tape

After explaining to the students that I was going to break them up into teams and teach them to start seedlings for their fall garden, I mentioned that they would also be making teams. After some confused looks,  I used the quiet greenhouse to explain that the teams were made up of plants that work well together, in other words, companions. 

Background information:

Some varieties of plants, such as those in the genus Brassica, have similar nutrient requirements and are susceptible to the same pests. For example, planting Broccoli, Cabbage, Kale, Kholrabi, and Collards (all Brassicas) next to one another can lead to an infestation of Cabbage Moths.  These little white butterflies lay their eggs on the undersides of the Brassica leaves until they hatch into hungry caterpillars that camouflage themselves supremely well. In addition to creating a serious pest problem, the plants can inhibit the growth of each other by fighting over the same kind of nutrients. However, by acknowledging these problems, you organize your garden to reduce pest problems and nutrient deficiencies. 

In other words, due to all the variables that can limit plant germination
outdoors, it is better to seed each hole heavier than you would indoors.

Below is a list of plants that might grow well next to one another. Generally, one plant is an herb with fragrant leaves and will repel flying insects while the other is always an unrelated species:  

- Bok choy and Celery

- Broccoli and Onions
- Cabbage and Dill
- Cauliflower and Rosemary
- Chard and Fava Beans
- Garlic and Kale
- Lettuce and Radish

- Spinach and Strawberries 

Activity Instructions:

First divide the class into groups and assign each group to seed a different combination of companion plants. Once each groups has received their seeds, they will need to fill their seedling containers with potting soil. It helps to have a large container set out, such as a wheelbarrow, so that multiple groups can fill their trays with potting soil at the same time. In addition, a wheelbarrow will give you and easy way to moisten the potting mix before the students put the seeds in their containers. Though moistening the potting mix is not required, by wetting the mix before the students fill their containers, they will be able to easily poke a finger in each cell of their container to the depth of their fingernail. 

Two students show off their seedling trays newly topped with Perlite.

After the students have made a hole in each cell in their container they are to take ONE seed and put it in the hole. After the students have carefully placed the seeds into their containers, they should cover their seeds with a thin layer of perlite to help the soil retain moisture while reducing the chance that fungal gnats will want to lay their eggs in the seedling trays. Fungal gnats prefer dark colored soil because it is indicative of moisture, however the white Perlite can be used to fool these pests... sometimes.

Finally, the students need to label their trays by sticking some masking tape marked with a permanent pen to the side. The students will want to record their name, date seeded, and plant variety. Labeling the trays will help the students identify their variety of seedling and track its growth as it matures into adulthood. 

LBHS: Aerobic Composting

Workshop Series

Hello again, the following post details my progress working with students in the gardening elective at Luther Burbank High School in Sacramento. As a result, this particular post will become augmented as I develop more curriculum for the students. 

The school itself has an amazing infrastructure complete with 20 raised beds, a greenhouse, shade house, animal stalls and a barn which houses a tractor! Unfortunately, after the school lost funding for its gardening program 7 years ago many of these resources have been neglected. The tractor now gathers dust, the barn is used for storage, and animals are no longer present on campus. However, due to the superhuman efforts of teacher, Aaron Mcclatchy, and Health Corps Coordinator, Isa Del Signore Dresser, I have been given the opportunity to teach the students some skills they can use to revive their gardenscape (picture below).

Aerobic Composting Building and Scavenger Hunt

The aerobic composting workshop takes about 20 minutes including 10 minutes of discussion and 10 minutes of activity.

Workshop goals:

Teach students what compost is and how to make it. Teach students why composting is important.

Required materials:

- spade/pitchfork

- food scraps

- leaves, grass clippings, yard waste

- hose 

- staging area for compost pile

After an initial discussion where I asked the kids some simple questions, "What is compost?", "Why is composting important?", I realized that none of the students felt comfortable with the what or whys of composting. As a result I gave a brief talk about soil and plant nutrients to supplement the compost talk.

Background information:

Compost is decomposed plant matter. Composting is important because it replaces nutrients that were taken from the soil. Just like humans need certain vitamins and foods to stay healthy, plants need certain nutrients found in compost in order to grow and produce fruit. Plants gather nutrients from the soil and store those nutrients in their leaves, stems, flowers, and especially fruits. In conventional agriculture, we harvest the parts of the plant that have the highest concentrations of nutrients and ship them hundreds of miles away from where they were grown in order to feed people. As a result, those nutrients that were once in the soil are now also hundreds of miles away and over time the soil will become depleted of vitamins that plants need. By composting, we return the nutrients that we took from the soil. Thus, composting is important because it ensures that the land will continue to support us. 

How to make compost:

We make compost by layering high nutrient food waste with low nutrient yard waste and adding water. By sandwiching a layer of food waste in between two layers of yard waste we are creating an environment that is suitable for the decomposing microbes to breakdown the plant matter into soil. All we have to do is add water until the waste pile is about as wet as a wrung out sponge. 

Activity Section:

Each student is encouraged to help build the compost pile by digging a hole in the yard waste and placing a shovel full of food waste into the hole. 

The next part of the activity encourages students to go on a scavenger hunt in the pile and identify the following items:

- a piece of high nutrient waste

- a piece of low nutrient waste

- find something that doesn't belong in the pile

After the activity section of the workshop, one student is asked to water the pile as the others reflect on the pieces of waste they gathered from the pile. The students should be able to justify what they found as fitting into one of the three categories mentioned above.