Grade 3 School Garden Lesson Plan - Seeds Lesson; Seed Dispersal ~ Massachusetts

TRAVELING SEEDS
Grade Level: Grade 3
Description
In this activity students will learn that plants disperse their seeds away from the parent plants in In
this activity students will learn that plants disperse their seeds away from the parent plants in different
ways. They will observe some of the mechanisms that are used to disperse seeds and observe how the
seeds travels. Students will then develop a new strategy for seed dispersal and test their method of
release and travel.
Guiding Question
What are some of the different adaptation strategies that plants have developed to help them move
their seeds away from the parent plant to a new location where the seeds will have a better chance to
grow without competition.
Big Idea
Seeds stand a better chance of growing if they do not have to compete with the parent plant for light,
water and nutrients. Since plants do not move, fruits and seeds have developed unique structures to
help them move to a new place where there is less competition and the growing conditions are more
favorable for growth and survival. The main way seeds are dispersed are by wind, by hitchhiking a
ride on a passing animal, by floating in water, by being eaten by an animal and then moved through the
animal’s gut or by being moved by an animal or insect for other purposes. A few seeds can even move
themselves. Within these strategies there is a huge number of adaptations to increase the success of
the seed’s dispersal.
Learning Objectives
To understand that plants have developed a number of strategies to help them move their seeds away
from the parent plant to a location where they can grown without competition.
Materials
* Examples of fruits and seeds that exhibit a variety of different seed dispersal mechanism, including
wind blown, helicopters, hitchhikers, salt shakers, exploders, water floaters, edible fruits and nuts.
* Variety of seeds such as nasturtiums, marigolds, beans, peas, corn
* Paper bags and scissors for collecting seeds in the school yard
* Old wool socks or mittens
* Various Materials for building a new dispersal method including, paper, tissue paper, crepe paper,
feathers, cotton, wool, yarn, string, toothpicks, rubber bands, springs, pipe cleaners, glue, tape,
paperclips, etc., etc.
* 6 inch pots, buckets or large bowls
Lesson supported by a Specialty Crops Grant from the Massachusetts
Department of Agricultural Resources

Preparation
Gather together examples of various seed dispersal mechanism and fasten them to posters. You can
also use the photo images included in this lesson. Bring in additional seed examples for students to
observe.
Assemble a large number of materials that students can use to construct their new seed strategies.
Introducing the Lesson
Activate prior knowledge: Ask students what would happen if all the seeds that a plant produces
fell on the ground around the plant. What would it look like next year, when all the seeds grew up
underneath the mother plant. Would there be enough water, light, and nutrients.
Tell them plants are unable to move on their own. Yet their seed have developed wonderful ways to
move away from the parent plant so they will have a better chance of survival.
Ask them to think of ways that these seeds might travel. Have they ever seen a seed travel. On the
wind; on their socks or dogs fur; on water; by a bird or animal?
What might be some hazards of this as a means of transportation? Where might some of these seeds
be planted?
Discuss how seeds are formed: As the ovules in the ovary of the flower develop into seeds, the ovary
swells and becomes fleshy or hardens to protect the developing seeds. The part of the plant containing
the seeds is called the fruit. In addition to protecting the seeds, many fruits are designed to help seeds
ultimately disperse, as described below.
Fruits take many forms. The two general categories used to categorize fruits are fleshy and dry.
Fleshy fruits include apples and berries. They usually have sweet, fleshy ovaries surrounding the
seeds They are enticing for birds and animals who, in turn, scatter seeds away from the parent plant.
Dry fruits. The ovaries of dry fruits also contain the seeds, but the ovary walls are thin and dry, rather
than fleshy. Some dry fruits like pods spilt open, letting the seeds drop out. Some dry fruits have
fluffy or feathery parts on the outer coat, which help the fruit float on the wind. Other dry fruits, like
those of the maple tree, consist of stiff, wing-like parts that allow the fruit to twist or flutter to the
ground.
Engage Student Interest: Tell students that they are going to be seed scientists and study some of
the ways that seeds travel away from their parent plant to a more favorable location for growing. As
they study different seed adaptations, each team will develop a new technique that a seed might use for
traveling. Then we will set up an experiment to test the success of each method.
Procedure Total Time: two class sessions of forty-five minutes to an hour
Department of Agricultural Resources.

Part 1
In the Garden:
If a garden or outdoor space is available take the students outside to explore and seek out seeds and
fruits. If no space is available, collect a variety of fruits and seeds and bring them to the class.
1. Ask the group to explore the garden or schoolyard to look for fruits and seeds. Observe where the
seeds are located on the plant. What methods might they be using to travel? Find dandelions, asters
or other wind-blown seeds and ask students to disperse them by blowing on them, throwing the fluff
in the air, etc. How far to they travel? Use mittens or old wool socks to gather hitchhikers. Bring
along paper bags and scissors to collect different fruits and seeds to bring back into the classroom. (20
minutes)
In the Classroom:
1. Introduce each method of seed travel included in this lesson: Parachutes, helicopters, grasses,
hitchhikers, water floaters, exploding pods, salt shakers and fruits and seeds that would be attractive
to birds and animals. Bring in samples of each method or use pictures to show each strategy. Let the
students explore the plants and pictures to understand how the seeds might move. What questions to
they have about each. (20 minutes)
2. Divide the class into small groups and give each group a number of the seeds and fruits collected
from the garden or schoolyard, or that you brought in for them. Ask each group to predict the method
of travel these seeds might have used. Invite the groups to show their seeds and then demonstrate how
the seeds might travel. (10 Minutes
Part 2:
In the Classroom
1. Divide the class into small groups. Review seed dispersal strategies. Challenge each team to
invent a strategy for seed dispersal. The seed might float on wind, explode, hitchhike, be thrown
from the plant, float, be eaten by a bird or animal, or some other mechanism that they develop. (10
Minutes)
2. Supply students with the a variety of miscellaneous materials to help them create the new seed
dispersal. These materials should be used to modify seeds. Provide a number of different seeds for
them to use. Let them know that they will have a half hour to build their seed dispersal mechanism.
Suggest that each team draw their separate design and then the group should decide on one strategy to
build. (25 minutes)
3. Ask teams to develop and write a story for how their seed will travel (10 minutes).

Wrap Up
Ask each group to demonstrate their seed dispersal mechanisms by launching it towards a six inch pot.
Give each team three try to reach the pot. Offer teams a chance to modify their design to improve
success. (15 minutes)
Assessing Student Knowledge:
Ask students to identify one plant that travels by each of the following methods: wind blown,
helicopters, hitchkikers, salt shakers, exploders, water floaters, fruits, nuts. Invite students to act out
each seed dispersal mechanism.
Extensions
Research how the seeds of different fruits are naturally dispersed.
Write creative travel stories from the perspective of a seed that has left its parent with the help of a
natural force.
Find pictures to compare seeds to human made objects, e.g. maple seeds and helicopters; burdock and
velcro.
* MA Department of Education Standards in this lesson *
Life Cycles
Standard 3. Recognize that plants and animals go though life cycles.
Standard 9. Recognize plant behaviors
Books and Resources
Massachusetts Agriculture in the Classroom Newsletter on Seeds
http://aginclassroom.org/Newsletter/spring2006.html
A Handful of Seeds: Seed Saving and Seed Study for Educators
Lessons linked to California Educational Standards Practical Information on Seed Saving for School
Gardens History and Lore. On the web at: www.oaec.org/school-garden/handful-of- ?seeds
Botany for All Ages: Discovering Nature Through Activities for Children and Adults by Jorie
Hunken and the New England Wildflower Society (The Globe Pequot Press) 1994.
Hands-On Nature: Information and Activities for Exploring the Environment with Children edited
by Jenepher Lingelbach 1986.
Grow Lab Activities for Growing Minds from the National Gardening Association, 1990.
Please visit the Massachusetts Agriculture in the Classroom website at www.aginclassroom.org
to tell us how you used this Seeds Garden-Based Lesson

Seed Dispersal Strategies
Wind Blown Seeds
Plant Parachutes: Some seeds are very light
and attached to tiny hairs, silken threads or fluff
that act like parachutes that allow the seeds to
float on the wind, sometimes for miles. Seeds of
plants such as the milkweed (pictured on right),
cottonwood, dandelions, goldenrods, thistle,
lettuce and pussy willow are dispersed this way.
Watch these seeds to see in which directions the
wind is blowing. Do they all travel at the same
height? Will they all wind up at the same place?
Helicopters: Seeds of plants like maple
(pictured on right), elm, basswood, ash and pine
have wings. They spin away from the tree and
ride on the air like gliders.
Grasses: Seeds of grasses also contain tiny hairs
to help them move in the wind.

Hitchhikers
Hitchhikers: Some seeds, such as those of
burdock and beggar tick, travel by sticking to the
fur of animals. The burdock seeds pictured on the
right have rows of hooks to grip the coat. These
seeds may travel for several miles before being
brushed off, chewed from the fur or released by a
burrowing animal. Notice where these seeds are
located on the plant.
Water Floaters
Water Floaters: Some seeds may get washed to
a new home by a hard rain. Others sail on rivers
like small boats. A few seeds, like the coconut
can sail across the ocean and still germinate.
Special fibers around the seeds help the coconuts
to float. Many water traveling seeds have
inhibiting seed coats or chemical timing devices.
Cranberries have tight, but thin, skins that keep
them from drying out. (Lotus pods and seeds
pictured on right)
Self Movers
Self Movers: Some seeds move slowly along
the ground as if crawling. The seed of wild oats
and the common storkbill has a twisted tail.
When the tail is damp it partly untwists. As the
seed dries the seed twists again. This twisting
helps the seed move along the ground and may
also twist into the fur of animals. Mexican
jumping beans jump away from their parent
plant. Tumbleweed breaks off near the ground
when its seeds are ripe. As it rolls along, it
scatters its seeds. (Seed of common storkbill is
pictured on the right.)

Mechanical Methods
Salt Shakers: Some seeds are shaken out of
pods by the wind. Iris and poppies have openings
at the top and as the long stalks are blown or
shaken they scatter the seeds. An iris pod is
pictured here.
Exploding Pods: The pods of touch me
nots (jewelweed) and witch hazel pop open
explosively when the wind knocks them around
or an animals brushes by, sending the seeds flying
several feet. Violets pop open when they dry.
The squirting cucumber may throw its seeds as
high as a three story building.
Fruits that Shatter and Scatter Seeds: The
fruits of plants such as the coneflower and
echinacea shatter releasing their seeds slowly as
the wind shakes the plant or as a bird stops by
to feed on the tasty seeds. Scattered seeds may
reach several feet from the original plant.

Birds, Animals & Insects
Food for Birds: Many seeds are scattered
because of the fruit or pulp around them which
is attractive to birds. When the seeds are green
the fruit is sour. When they are ripe the fruit is
sweet. The birds may eat the fruit and drop the
seeds while eating or eat both the fruit and seeds,
which are protected by the seed coat and past
through the digestive system unharmed. (Image
of Viburnum fruit pictured ion right.)
Food for Animals: Acorns, hickory and other
nuts may be collected by squirrels. They bury
the nuts in the fall and may forget where some
are planted. Some seeds are shaken out of pods
by the wind. Iris and poppies have openings at
the top and as the long stalks are blown or shaken
they scatter the seeds. (Image of an acorn seed
on an oak.)
Ant Ferries: Almost one third of the woodland
wild flowers of the eastern forest, such as the
bloodroot, depend on ants to disperse their seeds.
Some seeds have a special, edible appendage
called an elaiosome, which is rich in sugar, oils,
amino acids and aromatic compounds attractive
to ants. They take the seeds to their nest, remove
the elalosome and feed it to their young. The
“useless” seed is moved to their compost heap, an
underground chamber containing decomposting
food scraps and other organic materials, perfect
for keeping seeds moist and supplying nutrients
to young seedlings.

Grade 3 School Garden Lesson Plan - Seeds Lesson; Seed Dispersal ~ Massachusetts

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Grade 3 School Garden Lesson Plan - Seeds Lesson; Seed Dispersal ~ Massachusetts