How to sow seeds in winter

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The ‘Lavender Double’ poppy was introduced by Seed Savers Exchange in 2023.

You’ve flipped through those beautiful seed catalogs. You’ve made your list of old favorites and new varieties you’re excited to grow. You’ve planned out your garden plot(s). You’ve ordered your supplies and seeds for the coming gardening season (or, if not, there’s still time: visit seedsavers.org!). And as those days get longer, you’re chomping at the bit for that last frost to arrive so you can soon begin working that soil in your garden. 

But did you know that there are certain seeds that you can sow when the temperatures are still cool and there’s still snow on the ground in some parts of the country? Late winter is a good time to sow hardy annual and perennial flowers such as poppies, bachelor buttons, delphinium, nicotiana, and calendula that germinate well in cold, wet weather. In fact, any plant that is “hardy” in your zone can be planted in winter. 

Soil and ‘Lavender Double’ poppy seeds placed in a gallon jug. Be sure to tape jugs shut around the middle with duct tape before leaving them outside for seeds to germinate.

How to winter sow seeds (tips excerpted from almanac.com):
Winter sowing is easy! Just sow hardy perennials in recycled milk or water jugs, place jugs outside, and let nature work its magic.

  • Use a clear, one-gallon milk or water jug; cut across the width of the jug just below the handle so that the bottom becomes a tray. (Try to leave an inch at the back so that the jug top is still attached and works as a hinge.)

  • Punch drainage holes in the bottom of the jug to promote drainage and in the top to promote ventilation.

  • Add 2-3 inches of potting soil to the bottom, moisten (soil should hold its shape when squeezed but not drip), and sow seeds to the depth recommended on the seed packet. Add a label inside with the name of the variety.

  • Tape the lid of the jug to the bottom, all the way around, with duct tape. Put the jug outside, making sure it’s in the sun but sheltered from the wind. 

  • Leave the plastic cap on the very top until the seeds germinate, then remove it to allow rain to enter. 

  • As seedlings grow, open the jug’s top and gently check the soil. If it’s dry, moisten gently and close the top. As the days get warmer, open the top during the day and close it at night.

  • Transplant seedlings before their leaves start to touch the sides and/or top of the container.