In January, we scoured the seed catalogues and native plant websites and came up with a wish list of plants we wanted to add to the garden. But buying individual small plants in spring would be expensive and seeds were the cheapest option.
Many native plant seeds won’t germinate immediately if you stick them in the ground. They require something called stratification to grow.
Stratification: the process of chilling a seed and then warming it back up to convince the seed it has spent a whole winter outside and it is time to germinate.
We decided to try the Milk Jug Seed Starting method otherwise known as “winter sowing.”
We started the seeds in January and February. This allowed for natural stratification of the seeds while also giving the seeds a jump start in the spring. The milk jugs act as mini-greenhouses harnessing the increasing sun and warmth of spring.
Some perennial seeds that require stratification in order to germinate include milkweed, bee balm, coneflowers and delphiniums, along with many other Minnesota natives.
Winter Sowing How-to
There are many how-to videos and websites, but the basics you need are:
a plastic gallon milk (or water) jug
a sharp utility knife or fine scissors
a roll of duct tape
a permanent marker.
You can use a sharpie-type marker, but it will wear away in the weather and you could end up with mystery seedlings. A specific fade-resistant gardening marker is better.
Tip: I went to our local chain coffee shop and asked the baristas to save all their milk jugs on a specific day. I ended up with over a dozen. Take them home and rinse them. You don’t need the caps.
Use a sharp knife to slice the milk jug most of the way around. Leave 1-2 inches of plastic as a “hinge” to let you open and close the container easily.
Poke several holes in the bottom and lower sides of the container to allow excess water to drain. Then fill the bottom of the container with a soil mix. Sprinkle or plant your seeds according to the instructions on the packet, and water well. Label your container. (I put in a plastic plant label and also wrote on the container itself). Finally, use the duct tape to seal the container back so that it is securely closed up.
Then place your milk jugs full of magic seeds outside to spend the rest of the winter in a sunny spot. Nature will do the rest. Snow will collect on them and then melt. When the days get longer and the temperatures warm, the containers will keep in just a bit more heat than the ground allowing for earlier germination. Make sure to check moisture levels once the soil has thawed.
You should get seedlings poking up well before seeds in the ground are germinating. Once you see sprouts (and it is a bit warmer) you can remove the top of the milk jug to allow the seedlings to grow larger before transplanting into the garden.
Leave a Reply