Richard R. MacMahon, Ph.D.
Method is Organic Gardening.
Organic Gardening (OG) is a system of gardening that depends upon the use of only natural fertilizers, natural insecticides and companion planting to maintain the health of a garden. Any method that teaches environmental quality should be simple and demonstrate a minimum of man-made additives to the natural system being studied. ( I am well aware that a garden is not strictly-speaking a natural system and actually does not come anywhere near being so, but it is a system that may be manipulated and studied by high school students with some assurance of success.) The OG movement is rooted historically in the type of agriculture that was practiced in this country and in Europe in the eighteenth and nineteenth centuries.
Method is simple.
What exactly is involved in OG? Plants are planted as seeds or set out as seedlings just as in any garden. However, the plants are aided in their growth only with natural products. No man-made chemical insecticides, fungicides, herbicides, rodenticides or fertilizers are used. Pest problems are solved in a number of ways, none of which involve chemicals that are foreign to nature. The simplicity of this method makes it inexpensive, low-tech, and time-intensive.
Method involves minimum of additives to soil and plants.
There are basically four categories of garden pests Ð insects, fungi, mammals and birds. Each group of pests is handled in a different way. Below is a partial list of pests and the methods used in their control.
Mammals:
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Rabbits Ð chicken wire around the garden, dog droppings as a repellent used only outside of the garden, blood meal as a repellent used inside of the garden
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Rodents Ð chicken wire, traps
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Birds Ð netting over crops
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Fungi Ð good husbandry, keeping refuse composted
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Insects Ð pyrethrin for flying insects, rotenone for leaf-eating insects, and Bacillus thuringiensis spray. Fly paper is also effective. Others may be picked off by hand. Powdered tobacco is also effective but I do not use it except on non-food varieties of roses and other flowers. Companion plantings of marigolds, nasturtiums and other species are also helpful in repelling insects. And beneficial insects may be purchased and placed in the garden. These include Lady Bug beetles, Trichograma wasps, Green Lacewings and Praying Mantis.
In order to build up the soil, there are a number of other natural additives that may be used. These include:
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Bone meal Ð source of calcium and nitrogen
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Blood meal Ð source of nitrogen, organic material and iron
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Greenstone Ð source of phosphate
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Ashes Ð insect repellent and source of potassium.
Finally, there is the gardener. Most insect pests can be removed by hand. There are not that many of them. I have removed potato beetle larvae, tomato horn worms, cabbage worms and others by hand and disposed of them by simply dropping them into a container of rubbing alcohol or just plain water. The insects die quickly and may then be added as a source of nitrogen to your compost pile. (Kerosene or old anti-freeze are also recommended for this task, but then where do you dispose of the remains? Certainly not in the compost pile.) Plain old-fashioned fly paper is still available and effective, as are mosquito dunks, which slowly release
Bacillus thuringiensis
into ponds or other standing waters.
What is involved?
For the students and/or teacher just starting into organic gardening I have prepared four lesson plans that should help students understand much more about soils and plant growth. These are:
Nature and properties of soils Ð Lesson plan #1
Seed germination and growth Ð Lesson plan #2
Composting Ð Lesson plan #3
Natural pest control Ð Lesson plan #4
These are included in a separate Appendix One. There is also included a separate Appendix Two of Teacher’s Notes to help in the teacher’s preparation of this unit. Appendix Three is a separate bibliography for organic gardening which includes a number of books that can guide a teacher and class through setting up an organic garden.