Tag Archives: pumpkin sprouts

OS10 Looking at Pumpkin Sprout Stems

Roots absorb water from the soil and send it to the leaves. To get from the roots to the stems the water must travel through the stems. When the leaves make sugar, they send it to the roots through the stems. Let’s find out how water travels through a stem.


Question: What does a pumpkin sprout stem do?


sprouts in plain and colored water

Sprout stems are mostly a greenish white color. The food coloring makes it easier to see some of the parts of the sprout.


2 Sprouted Pumpkin Seeds or the sprouts from Investigation 9


Razor blade

Magnifying glass

Custard cup

Pint Jar


Food coloring (red or blue)



Step 1: Open your Science Journal, write “Investigation 10” and the date.

Step 2: If you are using new sprouts, not the ones from Investigation 9, you need to put one in a jar of water with food coloring in it just as you did for that Investigation.

pumpkin sprout

A sprout has roots leading into a stem with cotyledons and a true leaf on it.

Step 3: Take the sprout out of the plain water and cut the stem off about 3cm above the roots. Set the top half with the leaves back in the cup of water. Cut the roots off about 1cm down and set the roots back in the cup of water. Carefully split the stem in half lengthwise. Try to cut it down into the root.

sprout stem piece

Sprout roots are white. Stems are green.

Seed coat and sprout piece

The seed coat is attached where the sprout root and stem meet.

Step 4: Examine the split pieces with the magnifying glass.

split plain stem piece

Splitting open a sprout stem shows the root part is solid but the stem is hollow.

Step 5: Take the sprout out of the water with food coloring. Cut it off about 3cm above the roots. Set the top half with the leaves back in the water with food coloring. Cut the roots off about 1cm down and set the roots back in the water with the food coloring.  Carefully split the stem in half lengthwise. Try to cut it down into the root.

stem piece from food coloring

The sprout roots appear blue but the stem doesn’t except where some food coloring got smeared.

Step 6: Examine the split pieces with the magnifying glass.

split colored sprout stem

The blue food coloring moves up through the thin walls of a sprout stem.

Step 7: Take the top piece out of the plain water. Carefully cut a very thin piece, as thin as a piece of paper, off the end of the stem.  Place a drop of water on a slide and put the piece on it. Do the same with the top from the water with food coloring in it. Place both tops back in their cups of water.


comparing stem pieces

The food coloring is in special places in the sprout stem. This shows that water moves through a stem in special places, not all over.

Step 8: Examine them through the microscope.

Step 11: Clean the slide and cover slip.

Step 12: Examine the top from the water with the food coloring with the magnifying glass. Try to see where the food coloring goes when it reaches the leaf. What parts can you identify in the growing tip?

Step 13: Discard the pieces of sprouts and clean up.



Plain stem:

Describe the outside of the stem

Describe where the stem and root meet

Describe the inside of the stem

Describe where the stem and root meet

Describe and draw what you see in the thin slice

Food colored stem:

Describe the outside of the stem

Describe where the stem and root meet

Describe the inside of the stem

Describe where the stem and root meet

Describe and draw what you see in the thin slice

Iodine turns purple in the presence of starch which is made of sugar. Describe where the iodine turns purple.

Describe where the food coloring goes in as it enters the leaves



Compare the stem and root parts of the sprouts. Can you tell where one ends and the other begins?


Why would the stems and roots be similar?



Where do you think the water and sugars move through a stem?


Why is it better to have the water and sugars move in special places?


What do you think the other parts of the stem do?


What do you think a stem does? [Think about a tree. Its trunk is a stem.]

OS9 Looking at Sprout Roots

Up to now I think the Investigations are pretty complete including the pictures. Starting with this Investigation there are some pictures missing because I split much larger Investigations into two different ones and made some other changes.

When you complete an Investigation, please let me know if something isn’t clear or doesn’t seem to work with the procedure I have given. This will help me fix those problems.

One thing you learn as a writer is how easy it is to see what you think you wrote instead of what you actually wrote. This is why a writer sends a book to an editor. For these Investigations, you are my editors.

Outside Project 9

Looking at Sprout Roots

No matter which way a seed points, the root still grows down into the soil as you saw in Investigation 4. A plant needs lots of water to grow and make sugar. The air is too dry so this water must come from the soil. Since the root is in the soil, it must get the water and send it to the rest of the plant. First let’s find out about how water moves through a sprout root. Then go on to Investigation 10 to see how water moves through a stem.


Question: How does water move through the roots of a sprout?

sprouts for Investigation


2 Pumpkin sprouts with their first true leaves



Food coloring (red or blue)


Paper towel

Magnifying glass



Preparation: You will need 2 pumpkin sprouts for this Investigation. You can use the same ones for the next Investigation if you do them the same day. You can start the seeds in a cup of dirt or you can start them in a glass jar like you did for Investigation 4. Using the glass jar lets you see how the roots grow and you don’t have to clean the dirt off.

Step 1: Open your Science Journal and write “Investigation 9” and the date.

Step 2: Put water in the jar so it is half full and add food coloring to make it dark.

sprout in colored water

When a sprout root absorbs water full of food coloring, the color goes with the water and shows where the water goes inside the root.

Step 3: Take the two sprouts out of the cup. Wash the dirt off the roots.

Step 4: Prop one sprout in the cup so the roots are in the colored water and the cotyledons and leaves are out of the water. Set it aside until color appears in a leaf. This can take up to a day.

Step 5: Set the other sprout on a moist paper towel. Examine it with the magnifying glass.

Step 6: Carefully spread the roots out and examine the roots carefully from the tip to the cotyledons. Draw and describe the roots.

sprout root

A pumpkin sprout has a main root that quickly branches off into many smaller roots.

Step 7: Cut about 1cm of the main root tip off with your fingernails or the knife. Put the rest of the sprout in a cup of water so the roots are in and the top is out of the water.

Step 8: Place the root tip on the table.

Step 9: Examine the root tip using the magnifying glass.

Step 10: Carefully split the root tip piece lengthwise and examine the cut sides with the magnifying glass.

Step 11: Take the second sprout out of the jar, rinse it, place it on a moist paper towel, carefully spread the roots and examine them with the magnifying glass.


colored sprout roots

Food coloring makes a sprout’s roots easier to see.

Step 12: Cut about 1cm off the main root tip. Put the rest of the sprout back in the jar with the food coloring.

Step 13: Place the cut root tip on the table.

Step 14: Examine this piece using the magnifying glass.

Step 15: Carefully split this piece lengthwise and examine the cut sides with the magnifying glass.



Describe the roots on the sprout without coloring:


piece of sprout root

A sprout root piece shows the root has a main piece with small rootlets going off of it.

Describe the roots on the sprout from the colored water:


colored root piece

Food coloring starts in the small rootlets and moves into the bigger root.

Describe the tip of the roots, plain and colored:


Describe the tops of the roots where they join the stem, plain and colored:


split open sprout root

Splitting the sprout root open where it joins the stem shows the root is solid and the stem is hollow.


Was it easier to see the different parts of the root with or without the coloring in the sprout? Explain.


What does the tip of the root do in the soil as the root grows? Why would cells here have to be different than in other parts of the radicle?


Why does the very tip of the root not absorb water?


Where are the cells that take water up the root to the plant located? Why are they located here?


split stem with coloring

Blue food coloring goes up through the outside parts of a sprout root so water must go up this way too.

How does the outside of the root change above where water is absorbed?


Why would this make it hard for this part of the root to absorb water?



OS7 Light and Sprouts

My seeds have sprouted. My sprouts are getting bigger. Perhaps yours are too. Here is Part 3 about growing the pumpkin vines with ideas about things you can study about them.

It’s time to start showing off our pumpkin plants. I will start a page of photo galleries of pumpkin plants. To get your own gallery so you can show everyone how well your pumpkins are doing, email me pictures of your pumpkin plant as it grows.

Project 1

Part 3

Growing Your Pumpkins


This is the hardest part of growing pumpkins for me. Maybe it is for you too. It only takes a few days to a week for the sprouts to appear but the time seems so long. One day there is that hook pushing soil aside or cotyledons open and pumpkin plants are growing.

The next step is keeping those plants growing and healthy.

Getting Started

Step 1: Only two miniature or sugar pie pumpkin plants can grow in one hill. Only one larger pumpkin plant can grow in a hill. More than two seeds should germinate so some have to go. Sometimes you can tell a sprout is very small or doesn’t grow very well. Pull these sprouts out. When they get their first true leaves, pull the smallest one. Do this again when the fourth true leaves appear until only three miniature or pie plants are left or two bigger pumpkin plants. Let the one grow to half a meter long, dig it out carefully and use it for Investigation 11. If the sun is very hot on your pumpkin plants almost all day, put up a shade to protect the plants from sunburn and dying. You can tell the sun is too hot if the edges of the cotyledons or leaves get dry and brown or they fade to light green.

Note: I hate to pull out a nice sturdy sprout and toss it away. It’s trying so hard to grow well. But it can’t stay where it is or none of the plants will do well later on. One solution is to transplant it someplace else. Pumpkins grow well with corn.

Step 2: While the plants are small, water them directly during the day. Once the plants start vining, water the vines by filling the moat and letting it soak in. While the vines are small, they may not need water every day unless it is hot. If the leaves wilt in the afternoon, you are not watering enough. Try not to get water on the leaves. Water your plants after the dew is gone but by early in the afternoon so the leaves get dry before sunset.

Getting Bigger

Step 3: Pumpkin vines grow extra or adventitious roots at every leaf node. The vines also grow in any direction. Before the roots grow, carefully move the vines to grow across your garden space. It’s best to do this while the vines are small and move them in the afternoon when the vines are softer. If the vine needs to be moved very far, do a little each day so you don’t break or bend the vine.

Step 4: The extra roots give you another way to feed the vines extra nutrients. This is very important for Halloween and giant pumpkins. For these vines, dig a little hole under the leaf node, put extra manure in it and cover it with dirt. Put dirt over the vines (not the leaves) to help protect them from borers and squash bugs. The dirt helps the adventitious roots grow faster.

Step 5: Especially for giant pumpkins, you may need to trim the vines and side vines when they get really long.

Step 6: Check your vines every day for insect pests and diseases. Pick off squash bugs and their eggs. Spray for cucumber beetles and flea beetles.

Keeping Records

Measure your plants for several days to find out how fast they grow. Write down how the plants change as they grow. Look at your plants at different times of the day and in different weather and write down comparisons. Describe how a leaf changes as it gets bigger then gets old.


When and where do your plants make adventitious roots? These are extra roots from the stems.

Giant pumpkin growers put dirt over the stems so the plants make more adventitious roots. What is the advantage of doing this?

When does your main vine put out a branch?

Does a branch vine grow faster than the main vine? Do you have to measure the entire vine to find this out?

Investigation 7

Plants need light to make food. A new sprout needs to start making its own food before it runs out of the food stored in the seed. How bright does this light need to be? What happens to a sprout if the light isn’t bright enough? Let’s find out.


Question: How does light affect a sprout?

materials needed


Long grow light

5 Styrofoam cups

10 seeds

Potting soil


Metric ruler

Plastic wrap

Books or blocks of wood to make steps for the cups


Step 1: Open your science journal and write the date. Put down Investigation 7. Copy Table 1 into your journal.

Step 2: Number the cups 1 to 5 and fill them with potting soil. The soil should be 1.5cm below the top after it is firmed down.

Step 3: Add water to each cup so the soil is damp but not soggy.

Step 3: Measure 2.5cm from the end of the pencil and make a mark. Use the pencil to make two holes 2.5cm deep in each cup.

planting the seeds

Each pumpkin seed is planted at the same depth in the same type of cup and potting soil.

Step 4: Put a seed in each hole. All the seeds should be planted the same way. Add potting soil to fill each hole. Cover the cups with plastic wrap.

Step 5: Build steps under the grow light so the top of each cup is 5cm higher than the next one. The grow light should be over the tops of all the cups and only 2.5cm away from the top cup.

Step 6: Turn the grow light on for 12 hours every day. Check for sprouts every day. When sprouts appear, take the plastic wrap off the cup. Don’t let the soil dry out.

Step 7: Describe, draw and measure the length of the stems in centimeters of all the sprouts every day until the first true leaves appear. Write the measurement in Table 1.


sprouts on steps

As the pumpkin sprouts get farther from the light, they grow taller trying to get to it.


Table 1: Length of sprouts

Table 1

Table 2: Describe the sprouts

 Table 2


Why do you make all the holes for the seeds the same depth?

Think back to other Investigations and explain why 2.5cm is a good depth to plant pumpkin seeds.

Why should all the seeds be planted the same way?

Is it important to have the light turned on for the first two or three days? Explain why you think this.

Does it matter how close to the light a sprout is? Explain why you think this.


sprouts lined up

A grow light isn’t really bright enough for a pumpkin sprout even when it is very close. But a sprout does its best to get close.

What happens to sprouts farther away from the light?

Think back to other Investigations you have done. Why is it important for the new sprout to have a short stem?