
Curriculum
Connections
Garden
Investigations: Testing Partnerships
If
you focus on growing garden companions, you'll have lots of opportunities
to engage your students in authentic science. After all, many of the
companion planting strategies in practice are based on historical
observations or beliefs about which plants help each other grow better,
rather than on strict scientific research. And each garden system
is unique. Student teams might plant selected companions and chart
plant growth, insect visitors, or other factors over time, or they
might set up some controlled experiments. Their research questions
might be inspired by companion planting traditions (many of which
are featured in this newsletter); their own garden observations; or
what they've learned about plant needs from seed catalogs, books,
or the Internet. Here are some sample questions:
-
If
we surround a bed with garlic, will it have fewer pests than one
that has no garlic around it?
-
Will
we get a bigger corn harvest if we grow pole beans between corn
rows?
(Note: Give the corn a head start of a few weeks.)
-
Will
flea beetles bother radishes in our vegetable plot rather than attack
our cabbage seedlings?
-
Can
we get bigger pumpkins if we grow clover between the hills?
-
If
we put plants that are supposed to attract beneficial insects in
one section of our schoolyard, will we find more of the "good guys"
there than in other parts of the campus?
-
Will
spinach planted in the shade of peas last longer than spinach planted
in an open bed?
-
How
can we arrange lettuce and onions in a plot to get the best yield?
As groups plan investigations, help them consider the "steps" they'll
take in terms that help them think through the problem. Some of the
questions to ponder throughout the process are: What do we want to
find out about? How can we make the best observations? What do we already
think we know or have we observed about ____? What is the best way to
answer our questions? What types of data will we need? How can we make
it a "fair" test? What types of observations or measurements should
we take? How can we organize and communicate the data and results to
present the clearest answer or strongest explanation? They
can then mirror what scientists do by presenting their plans to peers,
who give feedback on the experimental setups.
Plant
Family Detectives
Before
you tackle companion planting, think about having your students dig
into plant families. Plants that are closely related often have similar
nutrient needs, attract or repel the same types of insects, are susceptible
to similar diseases, and so on. Learning
about these kinship ties can inspire close observations and help students
make planting decisions.
Flower
structure is the main criterion scientists use for grouping plants
into families. For instance, legumes, such as peas and beans, have
irregular flowers with a top and bottom petal surrounded by wing-like
petals (photo is of sweetpea flower). Cabbage family plants, including
broccoli, kale, mustard, turnips, and radishes, have four flower petals
arranged in a cross shape. Plants in both families have pod-like fruits.
(Other criteria for grouping plants into families include seed and
fruit numbers and types.) Although botanists have named about 300
plant families, a handful of enormous families represent many of our
garden denizens. These include the mint, mustard (cabbage), parsley
(carrot), lily (onion), rose, pea, daisy (aster), and grass families.
The potato family, solanaceae, features such garden favorites
as tomatoes, peppers, and eggplant, as well as highly toxic plants,
such as deadly nightshade. Although the flower structure is usually
telltale, the average size of different plant species in each family
can vary greatly; apple trees, for instance, are in the rose family.
Invite your students
to use their eyes and hand lenses to closely observe a variety of
flowers in the neighborhood, schoolyard, and garden. They should look
at and describe or draw each flower as a whole and then take a closeup
view. Have them examine the number and nature of different flower
parts (e.g., stamens). Ask individuals or small groups to identify
three flowers they think are closely related and use clues (evidence)
from their observations to support their choices. Ask, How do your
ideas (inferences) compare with those of other students? Which similarities
were most dramatic?
Once students
have done their own detective work, they can use the Internet, books,
or field guides to check hunches and extend their understanding. (Plant
Families, a book by Carol Lerner, is an excellent resource
for upper elementary students. It is out of print, so check for it
at a local library.) Here are some other family-related activity suggestions:
-
Research
the Latin names of plant families. What do they tell you about the
flower or plant? For instance, the Latin name of the mustard/cabbage
family, Cruciferae, means "cross-bearers" (see photo, right).
The carrot family name, Umbelliferae, is descriptive because
the flower head is curved up like an inside-out umbrella.
- Examine different
plants in the mint family, such as spearmint, basil, and oregano.
Try to guess which feature, besides flower structure, most plants
in this family share. (In cross section, the stems are square. Students
can feel this by rolling a stem between their fingers.)
- Design a wall
chart of common plant families found around the school. Press plants
or post drawings or photographs along with descriptions of each family.
Design
an Edible Landscape
Invite your students to see vegetables and herbs through a new lens
as they muse about a garden, schoolyard, or even one bed that uses
food plants artistically. They might start simply, by choosing a few
vegetable or herb plants to place into existing flower beds or incorporate
into new ones. (Have them think about mature heights when making decisions
about what to plant where.) A more involved project could include
perusing vegetable and flower gardens, seed catalogs and packets,
and other resources, and thinking about colors, textures, sizes, and
forms. The class can then use these resources, along with advice from
neighborhood gardeners, to begin to figure out planting schemes and
calendars and draft maps for different areas.
Imagine the possibilities
for practicing teamwork and honing math and art skills as students
puzzle out design details. How much space does a bean tepee take
up? How closely can we plant lettuce and parsley? What do we have
to plant and when should we plant it in order to have great colors
throughout the season?
Copyright© 2003
National Gardening Association
Growing Ideas Classroom Projects is a benefit for NGA's Members
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