If there's a citrus tree in your Arizona yard (or your neighbor's), keep an eye on it this week. In the University of Arizona Cooperative Extension guide Low Desert Citrus Varieties, the early 'Fukumoto' navel orange should be harvested by the end of October or early November, the 'Algerian' mandarin ripens in November, and the classic 'Parent Washington' navel is ready around Thanksgiving. Citrus season in the low desert is just getting started.
It's also a busy season for Arizona homeschoolers. KOLD News 13 reported on Oct. 19 that about 108,688 Arizona students now use Empowerment Scholarship Accounts, and that parents are trading ideas and materials at curriculum swaps, with more planned in Pinetop in November and Surprise in December. Lots of families are looking for hands-on science that actually holds kids' attention.
Here's one that smells great and costs almost nothing to start: a citrus seed lab with the fruit already on your counter.
What your kids will learn
Grades K–5
- That some plants grow from seeds and some can grow from a piece of another plant
- The parts of a fruit and a seed, and what roots, stems and leaves do
- Counting, sorting and comparing seeds from different fruits
- Observing, measuring and drawing changes over time
Grades 6–12
- Sexual vs. asexual reproduction: why a seedling can differ from its parent tree, while a rooted cutting is a genetic copy
- How rooting hormones (auxins) help a stem grow new roots
- Why commercial citrus trees are usually grafted onto a separate rootstock
- Planning a fair test, controlling variables and keeping a science journal
This week's activity: the great citrus seed count
- Gather three kinds of citrus. Try an orange, a lemon and a mandarin or grapefruit, from your tree or the grocery store. Kids can predict which fruit will have the most seeds.
- Cut and count. An adult slices each fruit in half across the middle. Kids count the segments and the seeds, then record everything in a simple table. (Yes, you may eat the evidence.)
- Clean the seeds. Rinse the seeds in water and gently rub off the slippery coating. Pick the plumpest ones.
- Start a seed bag. Fold the seeds into a damp paper towel, slide it into a zip-top bag labeled with the fruit and date, and keep it somewhere warm, like the top of the fridge.
- Check twice a week. Citrus seeds can take a few weeks to sprout, so patience is part of the lesson. Record the date each root appears.
- Look for a surprise. Some citrus seeds send up more than one sprout from a single seed. Older kids can research why (look up "polyembryony").
- Pot them up. Once roots are about half an inch long, plant each seedling in a small pot of soil and set it in a bright window.
Now try the other way plants make plants. A seed-grown citrus tree may not match its parent, and it can take years to fruit. That's why growers rely on cloning methods instead. With the Lemon Tree Cutting Rooting Science Kit or the Orange Tree Cutting Rooting Science Kit, kids try to root a real cutting, about 4 inches long, using the rooting powder in the box, and watch for the first roots to appear.
Each kit comes with step-by-step rooting instructions plus curriculum and worksheets for your grade band, emailed after purchase so you can print them at home. Choose the add-on version and you also get a second cutting, two 3-inch peat moss pots and two different types of soil, so kids can compare how each cutting does. Put your seed bag right next to the cutting, and you have a side-by-side lesson on seeds versus clones.
Join the growing community
Every kit includes an invitation to our Facebook group, Aardvark's Seed Planting For Little Hands, where kids and parents share progress photos, ask questions and cheer each other on. Arizona families are growing alongside young scientists in West Virginia and Arkansas, and while their gardens are heading into frost, yours is heading into citrus season. Post your seed counts and see whose fruit wins.
Start your citrus lab
- Lemon Tree Cutting Rooting Science Kit – Grow a Lemon Tree from a Cutting, with Curriculum & Worksheets: $19.00 (kit only) or $29.00 with 2 pots, an extra cutting and 2 growing mediums
- Orange Tree Cutting Rooting Science Kit – Grow an Orange Tree from a Cutting, with Curriculum & Worksheets: $19.00 (kit only) or $29.00 with the add-on
