SUMMER GARDEN PROGRAM
Lesson 2

PHOTOSYNTHESIS, CHLOROPHYLL PRINTS

HARVESTING
Lettuce, Spinach, Cucumbers, Grape Tomatoes
Objectives:

  • To examine the green pigment that allows plants to make their own food:
    Make a chlorophyll print.
  • To become more familiar with vegetables we might eat

MATERIALS

FOR ACTIVITY:
  • bowls
  • ziplock bags
  • watering can
  • trowels
  • scissors
  • small edible leaves (basil, mint, kale, spinach)
  • watercolor paper or small pieces of white cotton fabric
  • metal teaspoons
  • an image of a leaf cross section seen under the microscope
  • images shown in the video portion of this session can be found in the following two books: Plant, Eyewitness Books, DK Children, 2004
  • Gardening With Children, Brooklyn Botanic Garden, 2006)

INSTRUCTOR PREP:
  • Collect leaves from vegetables and herbs like basil, mint, kale, and spinach (3 or 4 per child). Do this just before the lesson or integrate it into lesson and do it together with the children.
  • Decide how to divide the students into 2 or more groups, each accompanied by an adult.
  • Be sure to have a table or another hard surface available where the children can work on the chlorophyll prints.

divider

WARM UP

Go-round: Say one vegetable or fruit you enjoy eating in summer.

divider

PHOTOSYNTHESIS
ASK: What do plants need to live and grow?
  • soil, water, air, sunlight


ASK: What do they do with the sunlight?
  • Plants use the sunlight to make their own food.


ASK: How do plants make their own food?
  • they follow a recipe: With the help of sunlight energy, they combine two major ingredients
  • water and carbon dioxide, to produce an energy rich product - sugar. The process is called
  • photosynthesis


ASK: Can we make our own food?
  • People, like all animals, get their energy from the foods we eat.


ASK: What would there be for people and animals to eat if there were no plants?
  • nothing

Trace a food back to its plant origin

Pick up one or more foods that are mentioned and follow their main ingredients back to their plant origin.

ASK: Where does ... come from? What is ... made of?

Take pizza, for example:
The crust is made from wheat.
The sauce is made with tomatoes.
The cheese comes from cows, and the cows eat grass and other plants.

ASK: How come plants can make their own food, but people and animals can't?
  • Plants can make their own food with the help of chlorophyll, a green pigment that traps sunlight energy.
    Plants use the sunlight energy to put water and carbon dioxide together to make sugar. Every green part
    of a plant has chlorophyll. Every green part of a plant makes sugar.

Show an image of a leaf cross section as it appears under the microscope.
Plant or Gardening With Children or another book.

divider

ACTIVITY

Divide the children into two groups, each accompanied by an adult. Explain the plan for the day: One group will start with harvesting and one group will start working on chlorophyll prints. Groups will switch activities after 15 minutes or so.

Depending on the number of adults and children, you can also have the two activities unfold one after another:
All children harvest first (maybe in several teams). Then all children make chlorophyll prints together.

MAKE A CHLOROPHYLL PRINT

If you didn't collect leaves from vegetables and herbs like basil, mint, kale, and spinach before the session, do it now with the children.

You can extract the chlorophyll from a plant part and create a beautiful image when you make a chlorophyll print.

Demonstrate technique:

  • Take a piece of fabric or watercolor paper. Fold it in half, and then open it up again. Place a leaf, topside facing down, on one half of the fabric or paper and refold the fabric or paper back over the leaf. Tape the folded paper or fabric to the table to hold it in place.
  • Using the bottom of the spoon and pressing very firmly, rub the spoon across the fabric or paper. Hold the fabric or paper down firmly with your hand.
  • Rub the spoon over the entire leaf area so that all the leaf's chlorophyll will be transferred onto
    the fabric or paper.
  • Collect the prints in your nature journal.

Distribute materials and assist children as needed.

TIME TO HARVEST

Team up adults with small groups of children and assign each team a different area in the garden. Ask adults to demonstrate/review the appropriate harvesting technique and safe tool use and then assist children as needed. With each vegetable discuss how much should be harvested that day

ASK: How might we prepare the vegetables?

ASK: How much of a particular vegetable or herb will be needed for a dish?

ASK: How much is ready for harvesting? Is there enough? Is there too much?

ASK: What should be done with extra vegetables?

For harvesting tips for specific vegetables link to HARVESTING TIPS:

CLOSING

Say one new thing that you found out about a plant in the garden. If you like, show your chlorophyll print to the group.

WATER

Check soil to see if it is dry. If it is, water till it is damp but not soaked.

info WATCH Terms and Techniques VIDEO