Starting seeds indoors may save money, but it can be a major undertaking. You have to have grow lights and space to set them up; you have to stay on top of watering and repotting as everything grows; and then, when it’s finally time to take your plants outdoors, you have to harden them off and hope that they survive transplant.
Being a fan of all things simple, I’ll be skipping all of that and wintersowing for the fifth year in a row.
What is Wintersowing?
Wintersowing is outdoor seed starting. Basically, you make mini greenhouses out of milk jugs and other empty food containers; fill them with a few inches of seed starting mix; plant your seeds; water them; put the lid back on; and stick them outside for the winter. They’ll germinate at the right time, and your plants will be better adapted to your climate than any plants that you started indoors or bought at the store. Don’t you love when the easy way is actually the better way?
I usually start saving my milk jugs in December. With a family of four, it doesn’t take long to accumulate them. Then, I do my planting in December and January. There’s zero urgency with wintersowing, so I just do it when I have time. The process couldn’t be easier.
How to Use Milk Jugs to Wintersow
What You’ll Need:
Milk jugs, with lids removed
A knife or scissors
A hole punch
Seed starting mix
What You Do:
Use a knife or awl to poke drainage holes in the bottom of your milk jug.
Cut the milk jug open four inches from the bottom. Leave an inch uncut at the back of the jug to create a hinge.
Use a hole punch to make two holes in the milk jug on the corner that’s directly across from the handle. This will give you a place to insert a twisty tie, so you can close your greenhouses. I’ll show you that in a bit.
Fill the milk jugs with two to three inches of seed starting mix.
Then, plant your seeds following the instructions on your seed packets. I usually plant nine seeds in each milk jug greenhouse.
Be sure to label all of your milk jugs, so you don’t forget what’s planted inside. I recommend using a black permanent marker for the job. The sun tends to fade anything else out (even colored permanent markers). One year we used a blue permanent marker, and all of my labels vanished. Not fun to sort out.
Water your seeds deeply. Then, use a twist tie to close your milk jug greenhouses. This will keep the wind from blowing them open, and keep curious animals out.
Then, place your mini greenhouses outdoors in a sunny spot. Check on them occasionally to see if they need water, and your plants will be ready for planting when spring gets here.
The milk jugs do a really good job of retaining moisture, so they shouldn’t require much watering or attention from you. I’ve tried other containers (berry boxes, take out containers, etc, and they just don’t work as well as milk jugs.
Oh, and don’t sweat it if your jugs get covered by snow. It won’t hurt them a bit.
Here are some broccoli starts from 2012. I got a 100% germination rate out of this container. Can’t complain about that! I’ll try to remember to post pictures as this year’s seeds start to do their thing.
Have any questions about wintersowing? Already a fan of wintersowing? I’d love to hear from you.