Winter Sowing Outdoors in Milk Jugs

Winter Sowing Outdoors in Milk Jugs

Winter sowing in milk jugs is a really fun way to grow a lot of plants easily and inexpensively. Let me explain to you how to do it:
Save your empty milk, water, or cider jugs. Wash them out, then drill 4 drainage holes in the bottom of each jug. Take a knife or sharp scissors and cut around the center of the jug, making sure to LEAVE THE HANDLE INTACT. This will create a "hinge" for your jug. 
Fill the bottom half of the jug with high quality seed starting soil.
Sow your seeds according to package directions. Some seeds should be sprinkled on the surface; others should be covered by some soil. When you are done, gently tamp down the surface of the soil and carefully water very carefully and slowly so you don't dislodge the seeds.
SAVE THE SEED PACKETS! You will need them later when you go to transplant.
Label the outside of the jugs with a permanent ink marker. You may also want to put another label inside for good measure.
Take duct tape or Gorilla tape and tape the top and bottom of the jug closed. Leave the cap OFF so water can get in. Put the jugs outside in a shady spot.
Timing: This should be done in late November, December, January, and February. The goal is to leave the seeds outside during alternate freezing and thaw cycles to break the seed dormancy by a process called stratification. 
Which seeds should you sow with this method? 
  • The first category are perennial seeds. These can be collected the growing season before or purchased in early winter. Most perennials need stratification and sowing them using this method is the easiest way to get them started. This is an excellent method for common milkweed, butterfly weed, and swamp milkweed. 

  • The second category are cool season annuals, vegetables, and herbs. Classic examples are calendula, annual bachelor's buttons, snapdragons, sweet peas, and larkspur. Read the seed packet carefully. If it says "sow outside 4-6 weeks before your last frost, the seeds are a candidate for winter sowing in milk jugs. Note that some seedlings don't transplant easily- poppies, carrots, and parsnips are examples that are much better direct sown in the ground in the early spring.

What happens next?


I can take many weeks, even months, for these seeds to germinate outside. Be patient and don't lose faith! One day you will look down through the hole in the top of the jug and you will see little baby seedlings popping up! Let them grow for a while, until they get at least one or two sets of true leaves. When they look lush and vigorous, remove the tape, slowly easy the clump of soil filled with seedlings out of the jug, and place it in a shallow saucer or basin of water. Have flats of 3 or 4" pots ready, filled with high quality potting soil. Poke a hole in the center of each pot and carefully tease a seedling out and replant it in the pot. Water and move your babies to a sheltered, partially shady spot for a few days to harden off and then, gradually, move them into the sun to grow on until they are large enough to transplant into the garden. If you are very careful and experienced in transplanting seedlings, you could also try moving them directly into a prepared garden bed, spacing them according to the directions on the seed packet. Be sure to shade them for the first few days as they adjust to their new home. I often create a tent with hoops and floating row cover. 

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