Winter Sowing for Perennials – Part 1

It is February 20, 2022, and I have just placed 5 different types of perennials that are beneficial for butterflies and bees…..outside in the snow in milk jugs! I just discovered this technique and am over the moon excited to share it with you. This is my first year of trying it, so I will share what I have learned so far and look forward to any tips and tricks that you may have to share with me.

What is Winter Sowing?

Forget the grow lights. Forget the hardening off of seedlings. Sow your seeds in milk jugs and let Mother Nature take care of the rest!

Supplies Needed

  • Clean, Clear milk jug or water bottles – Labels removed
  • Seeds
  • Soil – Promix Organic Moisture Mix was highly recommended for this
  • Utility Knife
  • Strong Tape ( I used duct tape)
  • Corkscrew or drill for making drainage holes in the containers
  • Tub (with garbage liner) to mix the soil and water
  • Wooden Spoon
  • Measuring cup
  • Water
  • Plant Markers (I used Plastic Knives)
  • Non-Fading Markers ( I used oil based metallic thin one for the plant markers and thick one for labelling milk jug on the outside)

Perennial seeds that I am trying

  • Poppies – they say poppies don’t transplant well…but I want to see how they work with this method
  • Native Seeds to attract bees and butterflies – Yarrow/Blanket Flower/Milkweed/Butterfly Bush

Video on how to do this process

Winter Sowing Schedule

I am in Zone 3/4 in Calgary and also deal with Chinooks which can make the process interesting. This is the general time frame that is said to work best:

January and February – winter sow perennials that need cold stratification.
Mid – Late March – winter sow hardier annuals
Late March – Early April – winter sow tender annuals, vegetables and herbs

Steps for Winter Sowing

  1. Create Plant Stakes for each seed with plastic knife
  2. Poke drainage holes in bottom of milk jugs in 4 places.
  3. Add holes to the top for ventilation and to allow more moisture in
  4. Cut jug leaving about 3 inches underneath handle to create a hinge to open
  5. Take off cap as you want water and snow to be able to get in a water seeds
  6. Mix potting soil with water (I used 1 cup of water for every 5 cups of soil). You want soil moist but not saturated.
  7. Place dirt in each milk jug 3-4 inches deep
  8. Add seeds (for small seeds place on top of soil, for larger seeds ensure they are covered as per package directions)
  9. Place plant marker in jug and also use marker on outside of jug to identify
  10. Cut duct tape to size needed to seal jug together again to make a mini greenhouse. You should be able to lift jug and have it all stay together.
  11. Take jug out and place in snow where they are in the open. In Calgary, due to Chinooks, take extra jugs filled with about 3 inches of water and place around jugs with seeds in them. They will freeze and create insultation from the huge weather changes and prevent the seeds from starting too early.
  12. Your mini greenhouses are safe from wind and animals, but will allow snow and rain to enter
  13. If there is a lack of snow or rain, you may have to water. If the jug feels quite light, it is a good indication that you have to water. Try watering it from below so as not to disturb the seedlings. Use a tray of water and place the jug directly in it to soak up the water.

Check back for what to do once the seedlings have sprouted and the weather is warmer. I am feeling a “spring” in my step! It felt so incredible to be able to do this while the snow was falling and the temperature was dropping. Please share any tips and extra tricks you have to winter sowing. And if you have any extra milk jugs you can spare, let me know….I’ll be there!