Winter Seed Sowing

Posted: March 3, 2014

I must be honest and admit that for the past four years my seeds were not started under the ideal conditions--grow lights in the basement or a warm and cozy kitchen windowsill. Rather, my seedlings saw the first light of day in a plastic milk jug in the cold outside air. This technique is called winter sowing.

Annuals may be sown using this method on a chilly day in March or April.  Begin with a gallon plastic milk jug.  White is the best color, but a yellow jug will work, too.  Use scissors to cut a U-shaped hole in the side, allowing the top to function as a flap.  Next, take a nail or other pointed object and punch about four holes in the bottom for drainage. 

Use the hole in the side to reach in and fill the bottom two inches or so with moistened seed starting medium.  Next, plant the seeds at the suggested depth described on the seed packet.  Use a permanent pen to mark the date and seed variety on the outside of the jug.  Then leave the lid off, and place the container outdoors near the house or another protected area. 

There is nothing more to do other than ensure that the seed starting mixture remains moist.  When daylight increases and the soil warms to the optimum temperature, the seeds will germinate.  The jug acts as a miniature cold frame.  As the seedlings mature, trim the plastic sides to allow room for growth.  The plants will already be hardened off and ready to transplant into your garden in May after the danger of frost is past.

I have had excellent success using this method.  In fact, most of the plants in my annual garden began life in a milk jug.  It is exciting to watch the seeds germinate and grow, and I have plenty of plants to share with others. 

Other gardeners have told me that they have had great luck with perennials, biennials, and vegetables using this winter sowing method.  Even tomato plants can be grown successfully by sowing the seeds inside the jug during late May or early June.

So, if you have thought that beginning plants from seed is too difficult or takes too much time, give this technique a try.  You just might get hooked on this rewarding part of gardening. 

Contact Information

Bill Goff
  • Master Gardener, Allegheny County