Seeding Onions

My first garden task of the year is seeding onions in January. This year, I'm growing Ho Shi Ko Bunching, Southport White Globe, Yellow of Parma, Cabernet, Bianca di Maggio and Tropeana Lunga.

I use boxes I made with cedar boards and fence pickets. I like these because they are deep enough to give the onions plenty of room until they go into the garden in spring.

They are filled to within a few inches of the top with 2 parts potting soil/1 part compost then topped with an inch or two of seed starting mix.

I make a shallow furrow, sprinkle the seeds along the furrow then very gently smooth the soil so the seeds are barely covered. 

I'm trying a new-to-me approach this year and putting the box in my unheated greenhouse. I've previously kept them indoors like other seed starts but am hoping for bigger bulbs with this technique. I'll mist the soil surface daily to keep it evenly moist until the seeds germinate then water as needed until it is time to move them to the garden beds in early spring. I'm gambling a bit because I suspect some of this seed is a little too old.

UPDATE 1/24: Germination started so only about 2 weeks despite the cool January temperatures. It's been about 35 at night and mid to high 40s during the day. I am pleasantly surprised by how quickly these started.

UPDATE 3/8: As suspected, the seed was too old for some varieties. The Southport White Globe and the Cabernet did well and I got about half of the Tropeana Lunga. The others sent up one or two at most. I bought new cipollini seeds and I'll try seeding more even though it is a bit late in the year at this point.