Tulip Garden Update: April 23, 1999

Today's Report Includes:

April Flowers
Never mind waiting for April showers, tulips are already blooming in 61 new gardens. And they have emerged in another 31 places, including Soldotna, Alaska (60.46 N, -151.16 W): "A week ago there was up to 20 in. of snow on our tulip garden. It melted over the weekend and the tulips just emerged," they proclaimed on April 19.

Today's Garden Data

But as you plot spring's journey north on your map, don't forget: There are people who are STILL WAITING. "As of April 19 we still have 20 inches of snow," report the gardeners in Utsjoki, Finland (69.90N, 26.90 E).

Challenge Question #17
"When do you predict the tulips in Finland will emerge? And when do you think they will they finally bloom?" (In your answer, give examples from other Journey North gardens as to how quickly tulips can grow.)

Holland is famous for growing tulips, so we wondered:

Why Do Dutch Farmers Cut the Flowers?
Discussion of Challenge Question #14

"We think that the Dutch farmers remove the bloom from the plant because they are interested in growing bulbs, not flowers. They sell the bulbs to other gardeners. Right now, we are selling bulbs at school (not tulips!) and so we know that people need to just buy the bulb. By taking the flower off, the leaves can make food just for the bulb. The bulb is then bigger and hardy."
Third Graders - Ardenia, Eliza, Jesse and Cameron of Ferrisburgh, VT (lthurfer@pop.k12.vt.us)
Leave the Leaves!
By the way, after your tulips bloom this spring, don't cut the leaves! Let them collect energy from the sun--that's their job. The energy will go into the new bulbs that will develop underground. Wait until the leaves are completely brown before cutting them off. That's when you know their job is done.
What's Going on Underground?
Dig up one tulip today, bulb and all, and sketch what you see. Plan to dig up another one every 2 weeks, until summer vacation. But before you start, predict what you will see at various stages. How will the size and weight of a bulb compare to its size and weight when you planted it last fall? How will it change over the next few weeks? (And don't listen to us- experiment! Is it true that the leaves make the bulb grow? Cut the leaves from some tulips and not others. Does this seem to affect the bulbs?)
Where is the Heat Coming From?
Discussion of Challenge Question #16

We asked you to explain the surprise we found in our own garden: "When the air temperature was 2 degrees F BELOW zero, why do you think the soil temperature was 27 degrees F ABOVE zero? Where was the heat coming from?"

From Ira W. Travell School in Ridgewood, NJ came the answer:

"I think that the soil is warming the bulbs from below the crust (which is warmed by the mantle), and the snow is insulating the heat from above the ground. As soon as the tulips are planted, they are getting warmed. Then during the winter, the snow is protecting the plants from the weather. It also preserves heat from the soil."
(fbarbi@ridgewood.k12.nj.us)

And from students at Canton Country Day School in Canton, OH:

"Our class thinks that the soil stays warm when the air above the snow is cold because the center of the earth gives off heat and therefore could keep the soil warm." (pjones@ccd-school.org)

Did You Know?
The temperature at the center of the Earth can reach 5,000 degrees F! Just think: A little bit of this heat found its way to your tulips this spring!

What Does the Ocean Have to Do With Tulips?
In our last report, Challenge Question #15 asked you to compare two places across the ocean from one another. We asked: "Why do you think tulips were already BLOOMING in Holland (52 N) when they were only EMERGING across the ocean, in places like Burlington, VT (44 N) and Franklin, NH (43 N)?"

Canton, OH
"We think the reason that the tulips are blooming in Holland, before here is because Holland has a lower elevation level then we do so it is warmer for the tulips to bloom."
Jimmy and Rammy, Canton Country Day School (pjones@ccd-school.org)

Ferrisburgh, VT
"We learned that most of Holland is below sea level. When we go up a mountain in Vermont, it gets colder. Even in the summer, it is cold up in the mountains. We think land that is below sea level must be warmer. The flowers would grow faster if the ground is warm."
Christopher and Kameron (lthurfer@pop.k12.vt.us)

But look at this map. It shows yesterday's ocean temperatures--at sea level--all around the world. The different colors show how warm or cold the ocean was. Now what do you think?

Challenge Question #18
"On April 22, what was the temperature--at sea level--on the coast of Holland? What was the temperature--at sea level--on the coast of New Hampshire? Now why do you think tulips grow earlier in Holland? (In your answer, explain the cause. Based on this map and Journey North tulip data, what can you say about temperatures in North America and Europe?)

Suggestions:

• Find a place in North America--at sea level--where the temperature was the same as in Holland.
• What is the latitude of each place?
• Find a place in Europe that has the same temperature as New Hampshire.
• What is the latitude of each place?
• Trace the latitude line from Holland over to the U.S. What is the temperature at each place?
• Track the latitude line from New Hampshire to Europe. What is the temperature at each place?

How to Respond to Today's Challenge Questions