Winter Sowing is a method of propagating new plants for your gardens simply by starting seeds outdoors in the winter using recycled deli containers or milk cartons. I've been doing Winter Sowing for many years and it is by far the cheapest, easiest way to get new plants for your garden.
Winter Sowing - Yes You Can Garden in Winter
First of all, let's gather some supplies:
- Several clean, plastic, gallon-sized jugs or plastic deli containers (that are at least 4 or 5 inches deep). The containers should be transparent so the sun can get to your seedlings.
- Potting soil – I just use a cheap potting soil. You don’t need anything with fertilizer in it.
- Sharpie or permanent marker that won't fade.
- Plant tags or labels
- Clear packing tape or duct tape
- A sharp knife or scissors
I winter sow mostly perennial and hardy annual seeds, but check the post on my blog for more information on sowing tender annuals and vegetables.
Steps for Winter Sowing:
- If you use gallon jugs, cut them around the middle neatly on three sides, leaving 5 or 6 inches on the bottom. You can discard the caps.
- Poke some drainage holes in the bottom of your container.
- Fill your containers with 3 - 4 inches of soil. Pack it down to fill in air pockets. Water the soil to get it fairly moist but not soggy. At this point make sure the drainage holes in the bottom of the container are working.
- Plant your seeds according to the directions on the packet. If you don’t have the seed packet to refer to, as a general rule-of-thumb, the smaller the seed, the more shallow you plant it.
- After your seeds are covered, give them a light sprinkling of water (I use a spray bottle). Skip this step if your soil is already moist.
- Next you’re going to tape the lid or top of the jug to the bottom. Poke some holes in the top of your taped up container for ventilation. And there you have it - a little green house. As you can see in my pictures, last year I forgot to take the caps off. Oops, I still had great results though.
- Write the name of your seeds on the container. Make sure to use a marker that will withstand weather elements. I also put a plant tag inside the container too.
- Place your container(s) outdoors. Select a spot where your little greenhouses will be safe from wind and animals, but be sure they are exposed to the elements. They need moisture from snow and rain. Some seeds like perennials need a period of freeze and thaw (called cold stratification). I put my containers on the deck where I can see the containers and watch them in the spring.
- Now all that's left is waiting for nature to do it's magic.
When the weather starts to warm up in the Spring, you’ll be able to see your seeds sprouting. At this point you'll need to make sure your new sprouts are getting enough water and ventilation. Poke a few more holes in the top of your containers and/or loosen some of the tape to allow for more air flow. The little seedlings will enjoy some days with the lids opened completely and then closed back in the evening.
Once it warms up and frost isn’t an issue, completely remove the lids. At some point, I will either divide and transplant the seedlings into bigger individual pots or directly plant them in my garden.
For more details on Winter Sowing and a list of seeds that work well with Winter Sowing, be sure to stop by the blog and read the full post - Winter Sowing - Yes, You Can Garden in Winter. I also have a printable checklist with easy to follow steps, as well as a chart to keep track of your Winter Sowing successes and failures. Go ahead and give Winter Sowing a try. You'll be so glad you did.
- Recycled milk jugs or deli containers (home)
- Potting soil (Home Depot)
- Seeds (Home Depot or Amazon)