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Which End is Up? ![]() Consider engaging young students in observing bulbs and predicting which part is the top (produces the shoot) and which is the bottom (produces the root). It's not, after all, obvious to the untrained eye. Once they've made predictions, they can set up investigations to test their ideas. Lay the groundwork
by having the class explore and compare different types of bulbs with
their hands and magnifying lenses, and list their observations on
the board. You can slice some bulbs in half so they can examine the
insides or wait to do this until they've conducted their investigation.
Based on their predictions and observations, have students decide
how they want to orient their bulbs in pots of soil (or in the outdoor
garden). They should label their pots and record how the bulbs were
planted. Once some of the bulbs have flowered, students can dig up
all the bulbs and compare the routes the roots and shoots took on
their journey. (The bulbs that were planted upside down are less likely
to bloom because they will have used their stored energy trying to
reach the light, leaving little for flowering.) Discovering
a Colorful History Possibly the most fascinating aspect of the history of flower bulbs is the economics and horticultural background of the industry, particularly the tulip trade. These hardy bulbs, which originated in the mountains of Turkey and other parts of central Asia (not in Holland, as many believe), were brought first to the Royal medicinal garden in England. As the idea of gardening for decoration not just for medicines took hold in the 1600s, Dutch horticulturists began propagating beautiful exotic breeds of tulips. Little did they know what a stir they would create. In the years that followed, wealthy people coveted these beautiful tulip breeds and spent scads of money on them. Illegal traders cashed in on the buying frenzy and earned outrageous sums. One bill of sale, in fact, recorded this transaction for just a single tulip bulb: two loads of wheat, four loads of rye, four fat oxen, eight fat pigs, twelve fat sheep, two barrels of wine, four barrels of beer, two barrels of butter, 1,000 pounds of cheese, a marriage bed with linens, and a sizeable wagon to haul it all away! When the craze, dubbed "tulipmania," finally subsided, the markets crashed and filthy rich businessmen were ruined. (Your students might want to research and compare how this investment craze compares with more contemporary ones!) Today, Holland raises and exports billions of flower bulbs each year; U.S. gardeners are the biggest buyers. Here are some Web sites your students might visit to dig deeper into the histories of these delightful packages: Bulbs
& More: History Exploring
Bulbs: From the Inside Out Inside a humble
bulb is everything needed to produce a flowering plant. Invite
students
to explore the secret life of bulbs by splitting one (or several)
in half. Consider including some of the bulbs we eat, such as
onions
or garlic. In the center of the bulb, they should notice a baby
flower bud surrounded by protective "scales," which
contain the food the bud will need to emerge and bloom. The
hard flat plate
at the bottom supports the bud and scales as well as the roots.
The papery outer skin (e.g., the onion skin), called the "tunic,"
protects the package. (Some bulbs, such as lilies, are called "scaly"
bulbs. Instead of the papery tunic, they have fleshy scales that
also store food.) When you provide the right conditions for bulbs to spring to life in the classroom, they typically take off . . . and fast! In fact, amaryllis grow so fast in a warm environment that students can practically watch them push upward. (Your class might capture this daily spurt using a digital camera and use the images to illustrate presentations about their discoveries.) Challenge your young scientists to consider how to best record growth of their indoor bulbs. Should we measure the growth of the flower stalk, leaves, or both? How will we ensure that they're measuring from the same point each time? They might also predict the final height (and tape markers on a wall) and/or the rate of growth. Ask, How can we assess the growth rate? (For instance, they might note the angle of the line on a handmade or computer-generated graph or subtract each day's stalk length from the previous day's length.) If you have more than one container of bulbs (which we strongly recommend), students might want to set up some investigations and comparisons. For instance, they might brainstorm the variables that could affect the growth rate hours of light, type of light, temperature, and so on and then design experiments to test their ideas. One school even reports setting up an Amaryllis-growing competition among different classrooms. Consider playing
pollinators! The
size and magnificence of amaryllis flowers invites close exploration
of flower parts, pollination, and seed and fruit production. Like
other lily family members, the flowers have six petals and six stamens
surrounding a pistil. Once
the flower is open, have students observe the parts carefully to discover
signs of the flower's readiness for pollination. (The three prongs
of the pistil actually open upward when the flower can accept pollen.)
Invite your class to "play the bees," using a cotton swab or paintbrush
to transfer pollen from one flower to another. Following successful
pollination, a swelling containing ovaries and then seeds will emerge
at the base of the flower. It would take 2 to 3 years to grow a flowering
plant from these seeds. Copyright© 2003 National Gardening Association Growing Ideas Classroom Projects is a benefit for NGA's Members |
Pg. 1: Coaxing Flower Bulbs Easiest
Bulbs for Grappling
with Growth Dutch
Bulbs Award! Fundraising
with Bulbs Planting
Bulbs Teachers
are raving about this book filled with actual school garden plans,
stories of how students participated in the design process, how-to
information, and resources.
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