Starting Onion Seeds

Its a very exciting time of the year when I can start seeds! I intended to get the onions started mid-February this year but that just didn’t happen.

First thing I did was to cut a bunch of toilet paper rolls in half making pots about 2" deep. Notice that I’ve marked my soil as seed — I made sure to get seed starting mix. Its a bit finer and doesn’t have large particles like what potting soils do. I moistened the soil a day ago. I like to water it up, mix it, and let it sit. The water mostly absorbs in a half hour but a day helps it to even out and penetrate larger chucks.

Next I put some soil in the bottom and push it down tightly. This gives a compacted bottom for the pot.

As you can see when I lift the pot out the soil stays in. After this I filled them the rest of the way up and tamping it down just enough that when pressed it bounces back to where it started. The roots will eventually come out of the bottom but I like that. I can trim them off before planting. I could plant the entire pot in the ground but I’ve found they don’t biodegrade fast enough so I just peel it off. By the time I’m ready to plant (8 weeks or so) the cardboard is not in great shape but the roots are holding the soil together.

Next its ready to plant the seeds! I learned last year that wetting a toothpick then touching the seed holds it on the end long enough to bring to the pot.

I then carefully bring it over and push down into the soil. The package recommends 1/4" so I push it just far enough then tamp down the soil around it to make sure there’s good seed to soil contact. These onions are a year old but the germination test from late 2014 said 92% and I found last year when I planted 4 seeds per pot I got 3–4 seeds per pot. I’ve decided to try just one per pot and if one doesn’t come up I’ll try planting another. I have a total of 95 pots and I don’t need that many seedlings anyways so having a few failures is fine.

One really important thing I learned last year was to mark your progress. I have a toothpick showing the last complete row and one that I move along as I plant. If you lose your spot its really hard to figure out where you were!

To end off I add some water (its a lot more gentle than the picture shows) just to be sure there’s good moisture at the seed and to settle the soil. Just a small amount is need because it only needs to be at the seed. Any excess will drain down.

Finally, I put them on my seed starting shelf. I’m leaving the lights on this year because I noticed last year that they help to raise the temperature. According to Johnny’s this is the optimum germination temperature. I’m not sure if onions are light sensitive but some plants need light to germinate. A small amount of light tells them they are close to surface and its good to germinate.

The lights are on a timer so it will cool down overnight and warm up again during the day, which again should help them by mimicking natural conditions. The shelves are setup in my furnace room so with the furnace off most of the night (temp set lower) it will also get a bit cooler.

I’ll leave the clear dome on just enough to get the seedlings up and then I take it off. For now its nice to leave on so the soil surface doesn’t dry.

As I look back over this post its a fairly brown and dull. I guess that’s why its so fun to start seeds — soon enough I’ll have green in the winter!