BARLEY, RICE, WHEAT, PEAS, AND SQUASH WERE SOME OF THE FIRST CROPS THAT HUMANS CULTIVATED IN ANCIENT FIELDS AND GARDENS. For thousands of years, people have treasured seeds that grow fast, foil pests, and yield tasty food. Long before people started playing with plant DNA in labs, farmers and gardeners were selectively breeding new plant hybrids, cross-pollinating and grafting favorite plant species to perfect their produce.
Today, modern agriculture is experiencing an onslaught of issues. Even with a wealth of science at our fingertips, food safety, crop diversity, and delicate ecosystems are all at risk as we fight to feed an exploding world population. Should an agricultural apocalypse ever befall us, forward thinkers have built seed vaults in places such as the North Pole, sheltering frozen seeds from thousands of plant species.
With water, sunlight, warmth, and nutrient-rich soil, you can grow your own food from seeds. In this chapter, you’ll have a race to see how fast seeds sprout, watch seedlings maneuver toward the light, and compost kitchen scraps to make fertilizer.
SPROUT SEEDS TO LEARN HOW SOME PLANTS USE CHEMICAL WARFARE TO DEFEND THEIR SPACE.
1 large rectangular planter, or several small flowerpots or cups
Potting soil
Ice pop sticks or wooden garden markers
2 or more of the following: lemons, oranges, black walnuts, pine needles, mint, eucalyptus leaves, chrysanthemum leaves, or tomato plant leaves
Mortar and pestle, food processor, or other tool for grinding nuts
Citrus zester or grater
Chia seeds or radish seeds
— Black walnuts are tree nuts, so be allergy aware.
STEP 1: Fill your planting containers with potting soil.
STEP 2: Subdivide large containers with ice pop sticks, with a section for each substance you want to test, plus one section with no substances, as a control. Label each section with an ice pop stick or garden marker. If using small pots, label one for each substance, plus a control.
STEP 3: Grind nuts, grate citrus peels, and chop or crush leaves to create mixable versions of the substances you want to test, cleaning your tools in between to avoid cross-contamination. (Fig. 1, 2)
STEP 4: Mix each of the substances into the top few inches (7 to 10 cm) of the section or pot you have labeled for them. Don’t mix anything into the control section. (Fig. 3)
STEP 5: Plant chia or radish seeds in each section. Make pencil holes to plant the same number of seeds in each section, or put a few teaspoons (13 to 17 g) of seed in each pot or section and mix them evenly into the soil.
STEP 6: Gently water the seeds.
STEP 7: Check the seeds every day. Record when they sprout in each section and which substances appear to have allelopathic effects on seed growth, preventing them from sprouting or growing. (Fig. 4)
Collect invasive plants such as buckthorn, garlic mustard, spotted knapweed, and nutsedge to test the allelopathic effects of their leaves, seeds, and fruit.
DIG A HOLE IN THE DIRT TO LEARN MORE ABOUT THE NUTRIENT CYCLE AND MAKE FERTILIZER FOR YOUR GARDEN.
Biodegradable kitchen waste such as coffee grounds, fruit and vegetable scraps, and egg shells
2 containers, such as buckets or cups
2 small pieces of plastic, such as milk container lids
Shovel
Soil thermometer or instant-read thermometer for meat
— Always call your local electric company before you dig to avoid underground power lines.
— This experiment will work best during months when it is warm outside.
STEP 1: Save some compostable waste from your kitchen. Divide the compost equally into two containers. Add a small piece of plastic to each container so you can observe what happens to plastic in compost heaps and landfills. (Fig. 1)
STEP 2: Dig two holes in the ground. They should each be about 1 foot (30.5 cm) deep. (Fig. 2)
STEP 3: Empty one compost container into each hole and cover them with dirt. (Fig. 3)
STEP 4: Label one compost pile “no water” and the other “water.”
STEP 5: Water the compost pile labeled “water” every other day or so.
STEP 6: When you water the compost, use a soil thermometer or another metal thermometer to check the temperature in each of your compost piles. Record it and compare it to the soil temperature in the surrounding areas. (Fig. 4)
STEP 7: After several weeks, dig up your compost to observe how well things are breaking down. Spread it out on a tarp or plastic bag to get a closer look.
STEP 8: Put the compost back in the ground and add it to your garden as fertilizer when it is ready. Recycle the pieces of plastic.
1. Test how packing down compost to limit oxygen or adding grass clippings and leaves affects compost.
2. Record how many worms you find in and near your compost piles.
CREATE A BOTANICAL OLYMPICS TO SEE HOW QUICKLY DIFFERENT PLANTS GROW.
1 large planter, or several small flowerpots or cups
Potting soil
Ice pope sticks or wooden plant markers
A variety of seeds and dry beans
— Be aware that dry beans can be choking hazards for small children.
STEP 1: Fill the containers with potting soil.
STEP 2: Subdivide large containers with sticks, with a section for each type of plant in the race.
STEP 3: Label each pot or section according to which seeds you will plant there. (Fig. 1)
STEP 4: Plant seeds or beans in each pot or section according to directions on the package. (Fig. 2)
STEP 5: Water the seeds you planted. (Fig. 3)
STEP 6: In your science notebook, make a guess, or hypothesis, about which plants you think will grow the fastest and why.
STEP 7: Observe the plants for a few weeks. Once they’ve sprouted, record in your notebook how tall they are each day and when leaves form. (Fig. 4)
STEP 8: Check to see whether your experimental results agree with your hypothesis.
1. Graph your results to make a growth curve for each type of seed. Do they start fast and slow down or continue to grow at the same rate?
2. Race the same type of seeds against each other, but water them with different liquids. Use tap water as a control.
3. See how density affects growth rate by racing seeds grown very close together against seeds grown far from one another.
Notebook
Garden
Magnifying glass
Camera (optional)
Flashlight
— Visit the garden at different times of day and night.
STEP 1: Start a garden guest book section in your science notebook for garden visitors. (Fig. 1)
STEP 2: Observe flower and vegetable gardens to find out what creatures are visiting. See what’s under leaves and crawling in the dirt, as well as who is sitting on plants and flying through the air. Use your magnifying glass for a closer look. (Fig. 2, 3)
STEP 3: Use your garden guest book to record, draw, and insert photos of the creatures you observe. Keep track of the day and time you saw the visitors, which plants they were on or near, and what they appeared to be doing. (Fig. 4)
STEP 4: Try to identify the animals, birds, insects, and arthropods you observed.
STEP 5: Visit the same garden or gardens over several days at different times of day to see what you find. Observe gardens at night, with a flashlight, to discover nocturnal visitors.
Did you find predators, for example, spiders? Make a garden guest food chain diagram that includes the plants in the garden. Where do you fit in?