Seedling starting

[Tucson Grower]

I would like to mention using cell-packs and trays on heating mats with lights - to germinate seeds and grow out seedlings for later transfer to the outdoor garden.

It is fun and rewarding, but my biggest frustration with this method is when the seed is too old, or some other issue causes the seed to not germinate as expected. Since I always have a huge list of plants I'm wanting to include in my garden, space on the heat mats is always at a premium. So, when seed that were sown, do not germinate, that means that other seed were not sown, in defference to the seed that were. In this case, garlic, Japanese lilac, and Amazon sourced sweet potato took up a total of 18 cells, where I could have sown other seed, which might now be growing. Not to mention twenty, 2-inch pots of Lima bean 'Fordhook 242' on heating mat at 80F, for more than 10 days now - and nothing.

[amyinowasso]

This is why I don't use the cell packs. I use paper cups. If there is no germination, they are removed and replaced. I can write on the cups. I WISH they made square paper cups, that would fit my trays better, but these are cheap. I remove each cup from the domed tray when it sprouts, so there is room for more. I have friends who have tried this and didn't like it, but it works for me.

[rdback]

Definitely frustrating - been there myself.

Now, when dealing with old seeds, I use the damp paper towel & plastic bag method. Then, toss those on the heat mat. As the seeds sprout, gently move them to a seedling pot. This year I'm going to refresh some old pepper seed - 2010 vintage. I'm certainly not gonna waste pots/soil for seeds that old. I'll take 50 or so seed and use this method. I'm only shooting for two or three plants. Any more than that would be a bonus, and gifts for friends.

jmo - Limas don't need 80F to germinate. Room temperature soil should be fine (65F or better). It also shouldn't take 10 days to see germination. I'd start looking at your seed source. Something ain't right, as they say.

[Tucson Grower]

Ooops - this morning as I went to water the majority of my cell-pack seedlings, I noticed that the temperature probe that controls the thermostat for the heat mats was inadvertently - no longer inserted in the space between two rows of cells, but instead was hanging out in space (in the open room air). I quickly inserted it back where it belonged, to discover that my seedlings root temps were 98.8F (a wee bit warmer than they aught to be). That then explains why they were much dryer than they should have been.

[heavyhitterokra]

Tucson, that sounds about like my luck.   Some years it's a good thing that Atwoods and Walmart sell transplants or else I wouldn't have a garden.

[Tucson Grower]

Yep, I was almost there.

I had actually overlooked the issue, the day before. The heat had almost extirpated the breadseed poppies; before I even realized what the true problem was. Most everything had almost died from becoming too dry, but I hadn't realized why. I had been thoroughly watering everything, morning and evening. That day I had watered everything in the morning, even more thoroughly than usual, and was thinking of skipping their evening watering, but, at the last minute thought to check them before making that decision. It's good that I did, or two days ago all of my seedlings would have dried out and died.