Richard R. MacMahon, Ph.D.
Although somewhat surprising, many students reach high school age without ever having participated in any gardening activity. Thus the teacher must assume total ignorance on the part of most students with regards to preparing the garden, seeding, weeding, cultivating, etc. The four included lesson plans are designed to acquaint students with some of the fundamental aspects of organic gardening.
Lesson plan #1: Nature and properties of soils Ð
This exercise is in the form of a laboratory exercise which can be xeroxed as is. (Just cover the words Appendix One and Lesson Plan). The students are asked to submit a report for each group. This encourages group cooperation and responsibility within each group. The success of the exercise depends largely upon how well the students cooperate.
Soil
Ð The teacher will have to supply one or more soil samples for the class. You may ask students to bring in samples of soil from home, but it is a good idea to have at least one sample that you provide. This sample should have at least 15 - 20% organic material. You can make sure of this by adding organic material such as compost to the soil. Students do not need a great deal of soil. Usually samples are too large, rather than too small. Remember, only enough soil is needed to fill a Petrie dish.
Lesson plan #2
:
Seed Germination and Growth Ð
This exercise is best accomplished during the school year in February and March. You will have to prepare some of the materials for this exercise. Most of the materials are easily obtained and can be purchased locally for much less than from a scientific supply house.
Lights
Ð A four-foot fluorescent shop light currently costs about $10.00 and is obtainable at Sear’s, Home Depot, and other such building supply stores. The lights come with two short chains from which they may be suspended. It is also desirable to include at least two 100 Watt incandescent bulbs in this bank of lights.
Timer
Ð An inexpensive timer, designed to control light circuits, is
generally available for around $5.00. You do not need the heavier units, which are designed to control air-conditioning units.
Table
Ð A six-foot rectangular table is all that is needed to place the plants
on. If the table is of any value, you should protect the surface from water and soil spills with a layer of plastic.
Light suspension
Ð the lights need to be suspended above the table at a height of about 18 inches. You may ask some students to construct a frame, or you may simply rest the ends of the lights on two sturdy cardboard or wooden boxes. You might also suspend the lights from a two by four that rests on the backs of two folding chairs.
Seeds
. Ð I have had the most success when I buy seeds in large packages at Agway or other suppliers of that type. I keep the seeds from year-to-year in a large metal canister. Most seeds seem to remain viable for three years, and it is much more convenient to buy them in large quantities, as well as a great deal less expensive.
The one problem with buying seeds is that they almost universally are treated with a fungicide to promote germination. Students need to be sure to wear protective gloves when handling seeds and to wash their hands thoroughly when finished. Fortunately seeds may be saved from the garden each year. Thus you may eliminate this concern entirely.
Lesson plan #3: Composting Ð
This exercise really is designed to be completed before the gardens are started. It can be done any time during the school year, but is probably best attempted during February and March. The vegetable materials to be composted can be collected by the students. Have each student save all of their family’s vegetable scraps for one week and then bring them to school. They may be kept in the refrigerator or freezer in a plastic bag while they are being collected.
The plastic bins to compost in are the type of plastic storage boxes that are sold in discount department stores and Woolworth’s (about 16”L x 10”W x 8”H). Sometimes these type of plastic boxes may be obtained used from fish stores or from restaurants that sell a lot of fish. I have used these fish boxes a number of times. All they need is a thorough washing to eliminate the fish smell.
Lesson plan #4 : Natural pest control Ð
This exercise can not be done indoors ahead of planting the regular garden, since it uses parts of the garden for the experiment. The principle involved is called companion planting. This involves planting marigolds, which are naturally repellent to insects, next to tomatoes, which insects will readily eat. The theory says that the marigolds will repel the insects, keeping them off of the tomatoes. I have had mixed results with this method.The students will also be using two natural insecticides, rotenone and pyrethrin. Rotenone is derived from the roots of a South American plant called Cube, while pyrethrin is derived from the plant
Pyrethrum
, a member of the Chrysanthemum family. These insecticides may be purchased at a garden supply store. Rotenone comes as a powder, which may be dusted on plants. Pyrethrin is usually a liquid but also comes as a powder. You must be careful, however, that these are the only ingredients. Many products offered have pyrethrin or rotenone as the main ingredient but may have other man-made ingredients added as well. You must read the labels completely and carefully.
Why are we using these two insecticides? Because they are both natural products that are effective against insects in the garden. And because they both break down in nature after about five days and leave no poisonous residue behind. Since they are both natural products, they are handled naturally by bacteria and other decomposers. But they are both extremely effective against insects. As the students plan their gardens, they must do some research on the space required. Some plants are larger than others and require more room between rows and more room between plants in the rows. I usually try to generate a contest and award prizes to the best garden plan, the most imaginative plan, the most efficient plan etc.