Here's a math lesson that grows. Phoenix's Desert Botanical Garden has a fall lineup packed with family events, and one of them is perfect for homeschoolers: Math in Bloom: Fibonacci Day on Nov. 23, a day exploring the math behind nature's patterns. It's included with admission, and the Garden's fall calendar also lists a pay-what-you-can Community Day on Nov. 10 and the kids' Cactus Clubhouse nature play space.
The Fibonacci sequence starts 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, and each number is the sum of the two before it. Nature loves it. Look closely at the face of a sunflower and you'll see seeds arranged in two sets of spirals, one curving clockwise and one counterclockwise. When you count them, the totals are often neighboring Fibonacci numbers, like 34 and 55.
You don't have to wait until Nov. 23 to start. Your kids can become pattern detectives this week, then grow the seeds themselves.
What your kids will learn
Grades K–5
- How to spot, trace and count spiral patterns in seeds and pine cones
- The parts of a seed: seed coat, embryo and stored food
- What a seed needs to germinate: water, warmth and air
- How to observe, draw and measure daily changes with a ruler
Grades 6–12
- The Fibonacci sequence and how to test whether a real seed head fits the pattern
- Germination physiology: water uptake (imbibition), enzyme activation and radicle emergence
- Writing a hypothesis and setting up a controlled experiment
- Recording quantitative data, calculating germination rate and writing a short lab conclusion
This week's activity: Spiral Detectives and the Sprout Test
Find a dried sunflower head (farmers markets and craft stores often have them) or a pine cone. If you're up in Arizona's high country, a ponderosa pine cone from the yard works beautifully.
- Trace one spiral. Using a pencil tip or a toothpick, follow one spiral of seeds (or cone scales) from the center to the edge. Mark its starting seed with a tiny dot of washable marker.
- Count both directions. Count all the spirals that curve clockwise, then all that curve counterclockwise. Big sunflower heads take patience, so let kids take turns and double-check each other.
- Compare to Fibonacci. Write your counts next to the sequence. Are they neighbors in the list? Close? Older kids can discuss why a real flower might not match perfectly.
- Set up the sprout test. Take two kinds of in-shell sunflower seeds: raw ones (like the black oil seeds sold as birdseed) and roasted snack seeds. Place five of each on a damp paper towel, fold it over, and seal each set in its own labeled zip bag.
- Predict and wait. Which group will sprout? Keep both bags somewhere warm and check daily.
- Record the results. Count how many seeds in each bag sprout and measure the roots. Roasting cooks the embryo inside the seed, so you should see a big difference. Talk about why.
Make it a full lesson. Our Sunflower Seed Germination Science Kit includes 10 sunflower seeds, absorbent germination paper and a resealable germination pouch, so kids can watch the seed coat split, the first root emerge and the shoot rise. Sunflower seeds typically sprout in 2–5 days, which keeps young scientists excited. Choose K–5 or 6–12 at checkout, and you'll receive four lessons plus a daily observation log, a root-length measurement chart, and a reflection page (K–5) or lab report template (6–12), all emailed after purchase.
Add a second seed for comparison. Pair it with our Heirloom Tomato Seed Germination Science Kit, with 20 heirloom tomato seeds in assorted varieties that typically sprout in 3–10 days. Racing a big sunflower seed against a tiny tomato seed is a great way to talk about stored food and seed size.
Join the growing community
Every kit purchase includes an invitation to Aardvark's Seed Planting For Little Hands, our private support group for families using our kits. After your order, request to join and we'll add you. Members share progress photos, ask questions and troubleshoot experiments together.
Post your spiral counts and sprout photos. Young growers from Tucson to Flagstaff, plus families in West Virginia and Arkansas, are sharing results, and it's fun to see whose seed head came closest to Fibonacci.
Get your pattern detectives growing
Count the spirals this week, sprout the seeds next week, and you'll have plenty to talk about if your family visits the Garden on Fibonacci Day.
