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Teacher’s guide



Teacher’s guide


This document was made for teachers participating in the Bulbs4Kids campaign.

It contains all kinds of information about flower bulbs and is intended to serve as

a teacher’s guide for lessons about this subject.

Flower bulb workbooks

The Bulbs4Kids kit includes workbooks that can be used during classroom

lessons. To learn more about flower bulbs, every student will receive his/her

own workbook that contains stories about flower bulbs through the seasons

as well as information about the history of flower bulbs. Also included are craft

and photographic assignments that can be done individually or with the class.


When you think of flower bulbs, you might immediately think of those

beautifully colored tulip fields in the Dutch bulb-growing region between

Leiden and Haarlem. But did you know that tulips aren’t the only beautiful

flowers that come from bulbs? And that the traditional bulb-growing region

isn’t the only place where bulbs are produced: they are also grown in the

northern part of the Province of North Holland. Time to immerse yourself in

the world of flower bulbs! Have fun!

Teacher’s guide www.bulbs4kids.com


Flower bulbs: a famous product

What do you know about the Netherlands? Maybe not a whole lot, but you can probably name three things: windmills,

wooden shoes and flower bulbs! Oddly enough, though, this list doesn’t reflect reality. Many windmills have disappeared

over the years, so there aren’t that many left. And wooden shoes? Who still wears wooden shoes? Almost nobody, right?

It’s only the flower bulbs that can really be associated with the Netherlands of today. And that’s been true for centuries.

You can see them everywhere, all year through. In the winter, you see them inside on window sills. For the rest of the year,

they bloom outside in gardens and parks where they’ve simply been planted in the ground or in large planters. And then there

are the flower bulb fields. Thousands and thousands of bulbs in bloom as far as the eye can see. Many people earn their living

from the trade in flower bulbs. They are sold to people all over the world. So it’s no exaggeration to say that Dutch flower bulbs

are a famous product!

Flower bulbs grow very differently. They are the real early birds. The way they grow is almost magical. One day, you see their

shoots coming up and before you know it, the flower buds are popping open. Suddenly, after a cold dark winter, the garden

is bursting with color. And now you know how this can happen. All the food needed to grow was already inside the bulb.

Besides that, flower bulbs need very little sunshine. That’s why they have a big jump on other plants in the garden.

Of all the flower bulbs grown in the Netherlands, hardly any are really native - or indigenous as we say - to the Netherlands.

Originally, almost all of these flower bulbs come from regions around the Caspian Sea, the Black Sea, and the Mediterranean

Sea where the summers are hot and dry and the winters are harsh and cold. Even now, it is this winter cold that many bulbs

need. In fact, the colder the winter, the faster the bulbs will be in bloom. This is why we plant them in the fall. At that time, the

ground is not yet too cold, so the roots begin to grow. Very slowly, the flower bulbs start to develop. Then winter begins.

They stop growing. Their dormant period has begun. In the cold ground, the bulbs are waiting for warmer weather. On a

certain day, that happens and the first shoots emerge above the surface. In the warm spring sunshine, the bulbs quickly

produce stems, leaves and flowers.

Flower bulbs - or are they corns, tubers, rhizomes or rootstocks?

Most people don’t know it but what we often call “flower bulbs” could also be corms, tubers, rhizomes or rootstocks. People

simply refer to all of them as bulbs. This is not so surprising, though. After all, they are often planted at the same time of year.

They are all purchased as dry products in a bag or box. And true flower bulbs as well as corms, tubers, rhizomes and rootstocks

all look rather alike. All of them contain food reserves that enable them to grow and bloom after being planted in the soil. A

rhizome, however, has a different appearance: this is actually a thickened underground stem that usually grows horizontally.

The tip of a rhizome often bends upward and forms a new plant there.

Summer-flowering bulbs

Most flower bulbs, such as tulips, hyacinths, daffodils and crocuses, bloom in the spring. As soon as winter ends, most plants

in the garden are still bare of any leaves. They need time to display any signs of life. Very cautiously, they start putting forth a

little green bud here and there.

Summer-flowering bulbs

Did you know that some kinds of flower bulbs bloom in the summer? We also plant these summer-flowering bulbs such as

gladioli, lilies, dahlias and begonias outside - but not in the fall. Because they originally come from regions with a tropical

climate, they cannot tolerate the winter cold. If we planted them in the fall, they would not come up in the spring. By then,

freezing temperatures would have killed them. This is why summer bulbs are planted in the spring. That’s also when you can buy

them. Many of these summer bulbs are less well known. After all, there are so many other plants on display in the garden at that

time! Meanwhile, the plants that grow from flower bulbs are not as conspicuous. Many people don’t even know that these are

flower bulbs!

Tulips = Bulb Dahlia = Tuber Oxalis = Rhizome

Teacher’s guide www.bulbs4kids.com



Tulips from Turkey

Our most famous flower bulb is the tulip. “Tulip” comes from the word Tulipa which is Latin meaning “the flower that looks like

a turban”. This might seem like a strange name but not when you know that tulips were already being grown and sold in Turkey

during the Middle Ages. At that time, men there wore a turban. So now you know! And here’s something else: the Dutch tulips

are descendants of the tulips that grew in Turkey. Turkey was a powerful country around 1550 when its ruler was a rich

sultan: Suleiman the Magnificent. His palace gardens were bursting with the most beautiful tulips. After all, he was wealthy,

and wealthy people can afford luxurious things. These things included tulips since tulips were highly regarded. It’s hard to

believe now, but in those days, a single tulip was worth more than the life of a human being!

An expensive gift

The sultan was very protective of his tulips. Only his very special guests might sometimes receive a few bulbs as a gift.

One of these famous guests was Mr. De Busbecq, a nobleman from Flanders who had been sent as an ambassador to Turkey.

De Busbecq then gave the tulip bulbs to a friend of his, Carolus Clusius. Clusius, who was in charge of the herb garden

belonging to the Emperor of Austria, gave the tulips a place of honor in that garden.

The trade in bulbs

Later, Carolus Clusius left Austria to live in the Netherlands. There, he became a professor at Leiden University and also the

head of the university’s herb garden. He brought the tulips along with him and conducted all kinds of tests on them. But as

beautiful and rare as they were, he refused to sell any. One night, however, some of his most beautiful tulip bulbs were stolen

from the garden. These stolen bulbs, originally from Turkey, were the beginnings of the trade in bulbs in the Netherlands!

Wild speculations in tulip bulbs

At first, only very wealthy people could afford to buy tulips, so it was considered very high class to have tulips in your garden. The

flamed and striped kinds were especially favored. So what happened then? Prices for tulip bulbs went through the roof! Many

people thought this was a great way to become rich overnight. They took their chances and sometimes even sold all their

possessions to buy a single bulb. Actually, this wasn’t even a bulb but a piece of paper stating that you were the new owner

of a tulip bulb. You didn’t even get to see the bulb itself because it was planted somewhere else in the ground. And sometimes,

there wasn’t a bulb at all because what you wanted to do with the piece of paper was to sell it to somebody else - and get a

much higher price for it than what you paid yourself. After all, it was all about making a profit. People were paying ridiculously

high prices for tulip bulbs.

An amount equal to 1,500 dollars for a single bulb was not at all uncommon. Rare bulbs sometimes commanded a price equal to

4,800 dollars in today’s money! This strange trade was called “tulipomania”.

Expensive and unusual

This speculation in tulips bulbs was short-lived. It lasted only from 1634 to 1637 when the government put an end to it.

During this brief time, some people became fabulously rich. Others were less fortunate and lost everything they owned.

Those were strange times but they generated a huge interest in bulbs, even in countries outside of the Netherlands where

people love them to this very day. Even so, it would take years before flower bulbs were grown in many gardens. They

remained expensive until around a hundred years ago. Even then, however, flower bulbs remained something special for

many more years to come. Today, all that has changed. Flower bulbs are no longer expensive and not unusual either. What’s

more, they are widely available. That’s why you now see them in almost every garden.

Lilies conquer the world

For a long time, tulips, daffodils and hyacinths were the most important flower bulbs. Many people think this is still so but

much has changed. The tulip may still rank first in importance (almost half of all the bulb fields are planted in tulips), but now in

second place are lilies followed by daffodils, hyacinths and gladioli.

Teacher’s guide www.bulbs4kids.com


The right soil for growing bulbs

Where are flower bulbs cultivated?

Long ago, flower bulb growers discovered that the soil right behind the dunes was perfect for this purpose. This is because

bulbs require very good drainage - no wet feet for them. These sandy (geest) soils behind the dunes are just what bulbs need

to thrive. Rainwater drains right through this soil. And the groundwater here is deep beneath the surface. Bulbs also prefer a

chalky soil. These geest soils provide that, too. This is because this soil is so close to the sea that it contains a lot of pulverized

shells. For a long time, the growers believed that they were restricted to these geest soils for growing bulbs. Although this is

true for daffodils and hyacinths, they later made an important discovery. Tulips, lilies and gladioli would also thrive in light clay

soils. This is why you now see flower bulb fields in many other parts of the Netherlands.

The cultivation of flower bulbs

When the bulb fields are in bloom, people flock to see them. For the growers themselves, the flowers are unimportant. All they

want is to produce nice big flower bulbs. That’s what it’s all about. The bigger the flower bulbs, the more money the grower will

make. So it’s no wonder that growers do everything they can to give their flower bulbs everything they want. That starts with

preparing the soil. On geest soils, the groundwater is deep beneath the surface so the soil can be plowed to a great depth.

This provides the flower bulbs with fresh soil again and again. But they need more than this. They also need fertilizer because

the soil behind the dunes is not rich in nutrients. For this reason, growers add the fertilizer or compost that the bulbs need to get

extra big and fat. Both plowing and fertilizing are thus important. This soil preparation has to be done before the bulbs are

planted. This happens in October. The growers use machines for this. Afterward, the fields are covered with straw or reeds. This

protects the bulbs from the worst of the winter cold. The mulch also keeps the sand from blowing away.

Spring is in the air!

Towards the end of winter, the layer of straw is removed. This is when you can start to see the first green shoots emerging from

the soil. Day by day, temperatures rise. This triggers the plants to grow faster and faster. As soon as the bulbs produce flowers,

the flowers are cut off (”beheaded”). What you see then are piles of flowers next to the fields. What a waste of beautiful flowers

you might think. But the grower has to do this. If he left the flowers on the stems, they would use up all the food that the plant

would produce. Then, the bulbs would remain small, and he couldn’t sell small bulbs.


After the flowers are removed, all that are left in the fields are stems and leaves. These parts of the plant produce the food for

the bulb to grow. Once the plants turn yellow, the flower bulbs have absorbed enough food. After this happens - between around

the middle of June and early August - the bulbs are removed from the soil. This is called “lifting”. After lifting, the bulbs are dried and

cleaned. The young bulblets are also removed from the large bulbs. We call this cleaning “peeling”. The large bulbs are sold. The

little ones go back into the ground in the fall.

New colors and shapes

Tulips come in many colors and shapes. And new ones are being added every year. Every new tulip gets its own name. This can

be a made-up name. But some tulips are named after famous singers, princesses and other celebrities.

First of all, the plant breeders with a new bulb flower have to be located. They are then asked if they want to name the new bulb

flower after a famous person. This could mean extra money for the grower because such a new tulip could be much in demand if it

gets written about a lot or even gets shown on television. To begin with, however, this new tulip will receive a number and will then

be reserved at the Royal General Bulb Growers’ Association. This organization also checks to see whether the name chosen by the

plant breeder is still available. If so, a real “christening certificate” is made which will then be signed during the “christening ceremony”

by the plant breeder and the person after whom the tulip is being named. The promising flower is then christened with Champagne

or water and begins what will hopefully be a nice long life.

Teacher’s guide www.bulbs4kids.com


How do you get a new tulip variety?

Just imagine that a plant breeder has a tall yellow tulip. Everyone thinks that its color and shape are wonderful. The only problems

are that its stem is not strong enough and the plant blooms too late in the spring. But the plant breeder also has a short white tulip.

Its shape isn’t as pretty but it blooms earlier in the spring. The plant breeder then crosses these two tulips. We call this ‘hybridizing’.

He puts a little pollen from one flower onto the pistil of the other flower.

Hybridizing tulips

He then collects seed from that plant. He plants this seed to produce bulbs. About five years later, these bulbs will bloom. This is

when the plant breeder finally gets to see whether he will get what he wants: a tulip with the right characteristics of both the yellow

and the white tulips. In this case, it would be a tulip that flowers early, is short and has beautifully shaped yellow flowers. As you can

see, this is quite a long and complicated process. The plant breeder has to know exactly what he is doing and needs to have a lot of

patience, too. Otherwise, he wouldn’t get anywhere!

From growers to gardens

Where do these flower bulbs go next?

Many are sold in countries outside of the Netherlands. They could be sold directly to a company that will export them. But many

bulbs are also sold at auction. Dutch flower bulbs are bought primarily in countries where winters are cold. This generates a lot

of money for the Netherlands. The Dutch government is thus very pleased that so many flower bulbs are grown in the Netherlands.

Many of these flower bulbs are sold to people with gardens. They buy them in a shop or garden center. Many people also buy

flower bulbs from a webshop.

Flower production

Many flower bulbs are sold to flower growers. These are people who buy bulbs to force them into flower. Instead of growing the

bulbs, flower growers use the bulbs to produce flowers. Most flower bulbs bloom in the spring. So how can you see tulips for sale in

shops at Christmas? This is the work of the flower growers. In their greenhouses, they adjust the temperature and humidity to get

the bulbs to bloom earlier than they would in a garden. Some of the bulbs are planted in the greenhouse right away. Others are

planted in boxes and put into a room where the temperature is kept cold. This is because bulbs need to be exposed to cold

temperatures first. Once they have been in the cold long enough, they are placed in the greenhouse where they will quickly produce

flowers. What happens to the bulbs once the flowers are harvested? These bulbs cannot be used again. Their rapid growth has

weakened them too much, so they are thrown away.

Teacher’s guide www.bulbs4kids.com


Flower bulbs on their way

A single grower can’t grow all kinds of flower bulbs in his fields. This is why wholesale and export companies buy their bulbs

from various growers. They can then offer their buyers many kinds of bulbs. Many bulbs are usually packed into large boxes

and crates. In a shop, you often see them packaged in nets and small boxes with pretty pictures on them. The pictures give

customers an idea of what to expect when the bulbs bloom.

Flower bulbs have to be treated with care. “Handle bulbs as if they were eggs” people say in the flower bulb business. This is

because a flower bulb can be damaged. But a diseased bulb should never be found among all the healthy ones. The bulbs

being exported to other countries have to pass especially strict inspections. If they pass, they get a plant passport. If not, they

can’t cross the border. The bulbs also have to remain in good condition during shipment. Trucks, airplanes and ships take them

all over the world. These modes of transport are designed and equipped to make sure that the bulbs are healthy when they

arrive at the customer’s location.










flower bulbs

Sie sorgen drinnen wie draußen für Stimmung

A cheerful sight both inside and outside

Every fall, countless flower bulbs are planted everywhere in the world, and not just in gardens but also on balconies.

After all, even if you don’t have a garden, you can use flower containers. Many flower bulbs are also planted indoors in the

fall. In pots and other containers, they give us a breath of spring even during the winter. Some of them will be blooming

as early as December. Do you know which ones these are? Hyacinths and daffodils are two examples. Hyacinths produce pink,

white and blue flowers. Daffodils are usually yellow, white or orange. These bulbs are being sold as individual bulbs or in

pretty boxes as early as the middle of September.

Hyacinths in the winter

You can use pots of various sizes for hyacinths. The best kind to use have a hole in the bottom. Placing the bulbs close

together will provide a better result.

1. Put some pot shards or a layer of gravel in the bottom of the pot.

2. Partially fill the pot with potting soil.

3. Place the bulbs on top of the potting soil. The tops of the bulbs should stick up just above the edge of rim of the pot.

4. Now continue filling the pot with soil. Tamp the soil gently. The “noses” of the bulbs should remain just above the rim of the pot.

5. Water the soil until it is nice and wet but not muddy.

6. Place the bulbs in a cool dark spot. The best temperature is around 13 degrees Fahrenheit but never warmer than 55 degrees

Fahrenheit. And always avoid freezing temperatures. Look at them every week to see if everything is OK. Keep the soil moist.

7. But what if you don’t have a spot like this? No problem: just bury the pot with its bulbs outside. Make sure that the rim of

the pot is about 4 inches below the soil surface. Here, you don’t have to water the bulbs because the rain will provide enough.

8. After 10 to 12 weeks outside, you can bring the bulbs indoors. Don’t put them right next to a window in full sunlight at first,

and keep them as far away from a radiator or heating vent as possible. Plants are attracted to light and this makes them lean in that

direction. For this reason, rotate the pot halfway around every day.

9. After a few days, the bulbs can be placed in direct sunlight. Be sure to keep the soil moist. In another few weeks, the bulbs

will bloom.

You can also get hyacinths to bloom without any soil. To do this, you can use a special hyacinth glass but a jam jar will work

just as well. The first roots will appear in just a few days. Care for the bulb just as you would for bulbs in a pot. You can’t put

hyacinth bulbs in water in a hole dug outside. Instead, look for a cool place like a cellar, garage or cabinet.

It’s also fun to paint your own flower pot first. If someone will be having a birthday soon, a pot with flower bulbs would

make a very nice gift.

The amaryllis is a GIANT!

“Amaryllis” is actually not the real name for this

gigantic bulb, but this is what almost everyone

calls it. Its real name is: “Hippeastrum” (say

hippyastrum), and it comes from the tropical regions

of South Africa. You can’t plant it outside but it

will do just fine indoors. You see them in various

colors such as orange, salmon and white. But red

is the most common color. Do you know what

makes an amaryllis so nice? It has such a long

planting period. If you want the bulb to bloom

very early, plant it in October. But you could also

wait for up to 6 months before planting it - until

the end of April! Actually, a flower bulb is a little

miracle. If you want a big miracle (and who doesn’t?),

plant an amaryllis. Have you ever seen such a huge

bulb? And take a peek at its clump of big fat roots!

With roots like those, the flower should be gigantic.

You might think that growing such a big plant would

be difficult. But you’d be wrong - all wrong! Of all the

bulbs, the amaryllis is the easiest to grow. Would

you like to know how? Put the pot in a warm place

in the light. As long as you don’t see anything

change, give it only a little water. When you see

the stem emerge, give it a little more water. Rotate

the pot every day. This way, the stem will not lean

towards the light. One day, you will notice the

color of the flower showing through the buds.

It’s now time for the “giant” among bulbs to start


Daffodils: just add water

The easiest daffodil to force into bloom is called the ‘Paperwhite’. And its flowers really are as white as paper. Anyone can grow

these bulbs - and quickly, too. You don’t even need potting soil. Paperwhites used to be grown only in Israel and southern

France. Now, the bulbs are also grown in the Netherlands. They can’t be planted outside because they would freeze there. They’re

real “indoor bulbs”. You can plant them from early October until the end of the year. It takes them just 4 to 6 weeks to produce

delightfully fragrant flowers.

1. Partially fill a shallow bowl (a glass one is pretty) with gravel.

2. Place the bulbs on top of the gravel. The tops of the bulbs should stick up just above the edge of the bowl.

3. Carefully pour water into the bowl. The surface of the water should just barely touch the bottoms of the bulbs.

4. Then add more gravel. This helps to support the bulbs.

5. Put the bowl right next to the window. This way, you can see what happens every day.

6. Even after a week, roots and shoots start to emerge. Be sure to keep topping up the water in time.

7. Then it happens: the clusters of buds start to open. What a beautiful sight! And don’t they smell good!

8. Keep an eye on the water level, and you can be enjoying your daffodils for about three weeks. When the flowers have

finished blooming, you can dispose of them since Paperwhites will not flower the second year.

Teacher’s guide www.bulbs4kids.com


Variety Planting depth Distance between the bulbs

Daffodil 6-8 inches 6 inches

Tulip 4-6 inches 4 inches

Crocus 4 inches 3 inches

Hyacinth 8 inches 6 inches

Snowdrop 2-4 inches 2-3 inches

Once the planting is done, cover the bulbs with the soil you dug out before. Write the names of the bulbs on the plant

markers. Stick the marker into the soil where you planted the bulbs. This way, you will know where you planted your

bulbs later on. If a hard freeze is predicted, cover the planting beds with a layer of dry leaves. With the Bulbs4Kids kit, you

and your class can plant bulbs around the school, in a school garden or in planters on the school grounds. Your school

would then look colorful next spring. Bulbs start becoming available in September in garden centers, supermarkets and

even in department stores.

Fun things to do with bulbs

The website www.bulbs4kids.com has many links to sites with fun things to do with bulbs like the Flower Bulb Game,

a video about the flower bulb auction, a coloring page and a flower bulb library.

Make your school playground beautiful

Flower bulbs in planters

Flower bulbs will grow very well in pots and planters. You can make them out of wood or just buy or borrow a few. Be sure that the

planters have holes in the bottom. If they don’t, the soil can become too wet. When that happens, the flower bulbs will start to rot.

You will also need some pot shards (or gravel) and some soil. Start by making a layer of pot shards or gravel at the bottom of the

planter. Then add a layer of potting soil. Now arrange the first layer of bulbs on top. These will be the ones that bloom

latest in the spring - like tulips. Cover these tulip bulbs with another layer of potting soil. On top of this, arrange another layer

of bulbs. These will be ones that flower a little earlier than the tulips. Good examples would be daffodils or hyacinths. Cover these

flower bulbs, too, with a layer of potting soil. Finally, arrange the bulbs that will bloom the earliest such as grape hyacinths or

crocuses, and cover them with potting soil. By planting various layers of flower bulbs, they will bloom one layer after another.

Have you ever heard of this method? It’s called “lasagna planting”. This way, you will be enjoying your flower bulb planter for a long,

long time.

Flower bulbs in the garden

Flower bulbs can be planted in many places in a yard: in the grass, under or among shrubs, and between other smaller plants.

To plant the bulbs, start by loosening the soil. Then dig a planting bed. This is a hole with a flat bottom. The depth of the hole should

be the same everywhere. Arrange all the bulbs of the same kind in the planting bed. Don’t plant them in straight rows but in little

groups. This will make them look a lot more natural. Here is a list of bulbs and how deep and far apart they should be planted:

Teacher’s guide www.bulbs4kids.com



Weeresteinstraat 10

P.O. Box 170

2180 AD Hillegom

The Netherlands

Phone: +31 (0)252 535090

Fax: +31 (0)252 535088




Versie US/CAN 2016

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