Living Root Garden School • Soil & the Underground • Name: ______________________
🔍 The Case
The case of the locked pantry — the food is right there in the soil, but the plants cannot eat it. Find the number that is locking the door.
pH is the number that tells you whether soil is acidic, neutral, or basic. The scale runs from 0 to 14: below 7 is acidic, like lemon juice at about pH 2; 7 is neutral, like pure water; above 7 is basic, also called alkaline, like soap at about pH 10.
Red cabbage juice is a pH indicator — a substance that snitches on acids and bases by changing color. Pink or red means acid, purple means neutral, and green or yellow means base. The color comes from a pigment called anthocyanin.
Most vegetables — tomatoes, peppers, lettuce, beans, carrots — are happiest between pH 6.0 and 7.0, where the most nutrients are available at once. Blueberries are rebels: they demand acidic soil, around pH 4.5 to 5.5.
Rule out the wrong cause: if leaves turn yellow while the veins stay green, that is iron chlorosis — the iron is in the soil, but the pH has locked it away from the roots. Dumping on more fertilizer will not fix it; the pH is the problem.
Ask: Which spot in your yard will test the most acidic, and which the least? Write your guess before you test.
Try: Brew your cabbage juice with a grown-up — chop a quarter of a red cabbage, pour boiled water over it, wait 10 to 15 minutes, strain it — then test four or more spots around the yard and write down every color.
Stretch (Teens & Growers ready for more): Track one crop in two spots with different pH for three weeks. Does your pH map predict the winner?
Tell: Fill in the log below — date, each spot, its color and pH — then finish this sentence in words or a labeled drawing: “The spot with the ___ pH grew ___ because ___.”
Date
What I saw
What surprised me
Date: ____/____/____
Date: ____/____/____
Date: ____/____/____
Date: ____/____/____
🛠️ Build It
Draw a map of your yard with a smiling or frowning face on each spot you tested, depending on what the pH said.
🗣️ Be the Teacher
Show someone your yard map and tell them why a plant can go hungry in soil full of food — in your own words, no reading off the packet.
🏅 I can…
☐ I can read my soil's pH with cabbage juice.
Portfolio check
☐ Guide read
☐ Case solved
☐ Ask, Try, Tell done
☐ Build It filed: Yard pH map
☐ Taught someone
☐ Badge earned: I can read my soil's pH with cabbage juice.
Living Root Garden School • livingrootgarden.com/homeschool/ • Free — print as many copies as you like. File this sheet with your portfolio log. Sprouts do the Read, the Case, and Build It; Growers try the Ask, Try, Tell stretch when ready; Teens do the whole packet — including teaching it back.