November is one of the busiest garden months in southern Arizona. The University of Arizona Cooperative Extension's November gardening guide for Pima County lists broccoli, cabbage and cauliflower starts for transplanting, plus beets, carrots, peas, spinach and kale to sow early in the month. The same guide warns that the first frost sometimes arrives in mid-to-late November, so it's smart to keep frost cloth handy.
The days are getting shorter too, even though most of Arizona skips this weekend's clock change. The Farmers' Almanac puts Phoenix's sunset at 5:37 p.m. on November 1 and 5:26 p.m. by November 15.
That gives your homeschool a great question for this week: how much does light really matter to a baby broccoli plant? Broccoli microgreens answer it quickly. They sprout in days, show clear differences in about a week, and at the end your kids get to taste their results.
What your kids will learn
Grades K–5
- What plants need to grow: light, water and air
- The life cycle from seed to sprout to seedling
- Seed leaves (cotyledons) and how they differ from true leaves
- Measuring seedling height with a ruler and recording it in a growth journal
- Comparing plants that get more light with plants that get less
Grades 6–12
- Photosynthesis: how plants turn light energy into stored food
- Etiolation: why seedlings that don't get enough light grow tall, pale and leggy
- Designing a controlled experiment that changes one variable, such as light, and keeps everything else the same
- Collecting data on several plants, calculating averages and graphing the results
- Writing a conclusion and suggesting what to test next
This week's activity: the Broccoli Microgreen Light Race
Plan on about one to two weeks from seed to harvest.
You'll need: broccoli seeds sold for sprouting or microgreens, two shallow containers (clean takeout trays work), potting mix, a spray bottle, a ruler and a notebook.
- Pick the right seeds. If you plan to eat your microgreens, use seeds packaged for sprouting or microgreens. Don't eat sprouts from garden seed that has been treated or coated.
- Prepare two trays. An adult pokes a few drainage holes in each container. Fill both with about an inch of damp potting mix and label them A and B.
- Sow thickly. Sprinkle seeds evenly over the surface so they're close together but not piled up. Press them gently into the soil and mist well.
- Keep them covered until they sprout. Cover both trays with a lid or another tray and set them somewhere warm for two to three days, misting daily, until most seeds have sprouted.
- Start the race. Uncover both trays. Put Tray A in your brightest window (an east-facing window is gentler than a hot west one) and Tray B in a dim corner of the room. Mist both the same amount each day.
- Measure daily. Pick five seedlings in each tray, measure each from the soil to the top of the leaves and record the numbers. Older kids can calculate a daily average for each tray and graph it. Everyone notes the color of the leaves and how sturdy the stems look.
- Harvest and taste. When the seed leaves are fully open, usually about 7 to 14 days after sowing, an adult snips a handful from each tray just above the soil. Rinse, compare them side by side, then taste. Which tray grew taller? Which looks healthier? Was the tallest tray really the winner?
Take it further with a real grow lab. A sunny Arizona window helps, but it can't control how many hours of light your plants get, or keep them from leaning toward the glass. The LED Grow Light Plant Stand Science Kit gives you two lighted shelves, each with a 2 ft, 10-watt full-spectrum LED light bar mounted 10 inches above the shelf. The stand is 26½ inches tall, 28 inches long and 12 inches wide, and each shelf holds one standard 10×20 microgreens tray. That's a top shelf and a bottom shelf for side-by-side experiments, such as changing the hours of light per day. Curriculum and worksheets for your grade band are emailed to you after purchase. Trays are sold separately and some assembly is required, so pick up a couple of 10×20 trays and a bag of microgreen seeds while the stand is on its way.
Join the growing community
Every kit comes with an invitation to our Facebook group, Aardvark's Seed Planting For Little Hands, where kids and parents can get support with anything they need. Post a photo of your microgreen trays, share your graphs, and see what other young growers are trying.
Arizona's homeschool community keeps growing. Families are swapping curriculum around the state, with more swaps planned in Pinetop in November and Surprise in December (KOLD 13 News). Whether you're in Tucson, the Valley or the high country, your kids can compare notes with young growers in West Virginia, Arkansas and beyond.
Set up your winter grow lab
Start the windowsill race this week, then bring the experiment indoors under steady LED light for the rest of the cool season.
- LED Grow Light Plant Stand Science Kit – Start Seeds & Microgreens Indoors on Two Lighted Shelves, with Curriculum & Worksheets: $200.00. Choose Grades K–5 or Grades 6–12.
