Winter Sowing Seeds: A Garden Project for Teachers or Families
Learn about the seasons & grow some tasty early season plants with this fun garden experiment that takes only 5 steps!
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We’re in our coldest weeks of winter, but you don’t need a windowsill to teach a lesson on gardening. Winter sowing is a garden practice that takes advantage of our cold and short winter days to “sync” plants with out season. Some of our native plants actually need this period of cold (called cold stratification) to signal that it’s time to sprout. For the purpose of this experiment, I’m using sugar snap peas because they’re tasty and one of the first veggies to sprout in the spring.
Why Grow Sugar Snap Peas?
They’re kid-safe
Every part of the plant is edible (and delicious!) including the leaves and flowers. The seeds are large and easy to handle
They like cool weather:
Few plants go from seed to fruit during the school year in our climate, but sugar snap peas will! They sprout when temperatures are regularly in the 50s, even if temperatures drop below freezing at night. That’s usually in mid-March in our climate
They mature quickly:
Sugar snap peas only need about 2 months to start producing flowers and tasty seed pods which means you’ll be able to harvest your tasty peas before the school year ends.
STEM Integration:
This project demonstrates "phenology”, the study of how plants respond to seasonal changes. Students observe that seeds remain dormant during winter and only trigger germination when environmental cues reach a specific threshold.
The Science of Seed Dormancy and Temperature
A common misconception is that seeds planted in winter will rot or sprout too early. In reality, sugar snap pea seeds are biologically programmed to wait.
While the bags are placed outside in January or February, the seeds will not sprout until the soil temperature inside the bag consistently reaches the 45°F to 55°F range, typically in March. This provides a clear visual representation of how plants use temperature to track the transition from winter to spring.
Project Materials List
To begin winter sowing, gather the following supplies:
Clear Plastic Zip Bags
Potting Mix: Any well-draining seed-starting mix will do!
Snap Pea Seeds: Sometimes called snow peas. Look for dwarf varieties that can mature in a container without needing a trellis to climb.
Permanent Marker: For labeling bags with student names, dates, and the number of seeds planted..
Duct Tape: To secure bags to a fence or railing if necessary.
Pot with holes: to water the soil so it’s wet (but not soggy) before placing the soil in the bags
How it works
The plastic zip bag acts as a "mini-greenhouse," protecting the seeds from wind and pests. When the seeds begin to sprout, you’ll be able to monitor the progress and transplant them into their proper place in the garden.
1. Mark the bags
Mark the bags with information about how many seeds were planted and who planted them (as well as a date)
2. Add soil to the bags
The soil should be wet but not dripping when it’s held. Don’t fill the sandwich-sized bags more than 1/3 of the way with soil.
3. Add seeds
Plant a few seeds to the top of the soil.
4. Place Outdoors
The seeds will stay dormant in the bags all winter and sprout naturally as the weather warms up.
5. Replant.
In March when the seeds sprout their first true leaves, plant into a garden bed or a container outside. They’ll continue to grow even if there are frosts and freezes.
If you try this experiment, let us know how it goes! You can find me on Facebook or Instagram. Happy Gardening!
