There are twelve milk jugs on our back steps, taped around the middle with duct tape, and Nate has stopped asking. Inside each one is three inches of damp potting mix and a sprinkle of native seed that needs a winter outdoors before it will wake up. I set them out yesterday afternoon, January 24, in a light snow, which is exactly what they're supposed to sit in.
This is called winter sowing, and it's my first real try at it. The idea is simple. A lot of our native wildflowers won't germinate until they've been through weeks of cold and damp. In the wild, seed drops in autumn, sits under the snow and sprouts when spring warms it. A milk jug is a tiny greenhouse that lets that happen on my steps instead of in my refrigerator.
Why bother, when I have a seed shelf?
Because the seed shelf is full, and because these plants don't want it anyway. The basement shelf is for tomatoes, peppers and onions, and this year leeks and celery, all things that want warmth and coddling. Natives like coneflower and New England aster would need weeks in the fridge in a damp paper towel before they'd sprout under lights. I have tried that. I forgot the bag in the crisper drawer until July.
The other reason is the back fence. Last May I planted 18 native plugs along the stockade fence, and by September some had taken off and two had been trampled during the fence repair. Plugs cost $3.50 each at the spring sale. A jug costs nothing but a few scoops of potting mix, and if even half of these work, I can fill the gaps for free and have extras for my after-school garden club in April.
How I made them
We go through about a gallon of milk every four days, so I started rinsing and saving jugs at Thanksgiving. Each one got the same treatment.
Four drainage holes in the bottom, poked with a heated screwdriver tip because my drill bit kept skating on the plastic. A cut all the way around the middle, just below the handle, leaving an inch uncut under the handle as a hinge. About 3 inches of Pro-Mix, wet until it felt like a wrung-out sponge. Seed sprinkled on top and pressed in with my palm, with a thin dusting of mix over the bigger seeds and nothing over the tiny ones. A plastic label inside, written in pencil, and the name written on the outside in paint marker, since regular marker fades in the sun by March. Then the top folded down and taped all the way around, and the cap thrown away so rain and snow can get in.
My mistake came on the very first two. I filled them with mix before making the drainage holes, then had to dump them out on the porch floor in the cold and start over. The other ten went faster.
What's in the jugs
Two jugs each of six plants, some from seed I shook out of dried heads along the back fence in October, some from packets I brought home from the library seed swap:
- Purple coneflower
- Black-eyed Susan
- New England aster
- Mountain mint
- Anise hyssop
- Wild bergamot, the native bee balm
Mateo labeled the bergamot jugs BEE BALM (WILD) in letters so big they wrap around the handle. I'm not correcting it.
The jugs sit on the bottom two steps, on the side we don't use, where they get snow, rain and some morning sun. They'll freeze solid more than once. That's the point. In March I'll start checking them on warm days, and when seedlings appear I'll open the tops on mild afternoons so they don't cook. By May they should be ready to split into small clumps and plant out along the fence.
This morning the snow on the lids looked like a row of small frosted cakes, white on white with a little blue in the shadows. Gus is asleep under his shed two yards over, and so, I hope, are the seeds.
