Lessons learned from seed starting

I used to start all my plants from seed and had pretty good success, but this year I made a big mess and learned a few things not to do. My technique is to plant 8 to 10+ seeds per pot in seed starting mix until the second set of leaves grow. Then I divide them into pots of their own. I make newspaper pots from one of these - https://www.lehmans.com/product/the-potmaker. (That part works well.) I grow them under fluorescent tubes, try to keep the leaves about 2” below the tubes, and use a timer to keep the lights on about 16 hours a day.

My mistake was getting impatient and repotting them too small because I was late getting started. Worse, I planted them into a mix of half potting soil and half garden soil. I thought it would be a good transition, but it was like sending toddlers into a coal mine. I wised up a couple weeks ago and potted the rest into seed mix and decided to start using Miracle Grow. They are much happier, and may even make vegetables by September.

The first picture shows how close I put the seed and the second picture (next post) shows my set up in the basement.

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Here is what they look like after repotting. You can see that it is tricky keeping them close enough to the light. BTW, the grassy plant in the middle is Charleston rice - that plant is determined to live!

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lathechuck's picture

Two things I learned this year.
1. Being locked out of the office due to COVID, I was able to haul my seedling trays outdoors every sunny morning, and back in before the night got cold. Best tomato seedlings EVER! Short and stocky in 1" combo-trays. LED light bars are nice, but no substitute for direct sunshine.

2. To prevent mildew or mold growth on slow-to-germinate seeds, you can soak them in 3% hydrogen peroxide warmed to 140F for five minutes. I thought that seemed a little harsh, but the beans I treated that way sprouted a day or two sooner than the ones in room-temperature water. (The old seeds never did germinate in either test chamber, but the treated seeds didn't rot as the untreated ones did.)

3. I let the arugula that I sowed last fall go to seed this spring, and when I gathered the seed, so much of it shattered from the pods that I have a whole new crop coming up between the beans that I wanted to rotate into that bed. It's OK. I got about a cup (8 oz.) of seed to plant elsewhere from the 4x6' bed. We'll be experimenting with microgreens this winter, with no shortage of seed!

I learned not to sow my seed too deep, but persistence pays off.

lathechuck's picture

I found a jar of saved kale seeds in my seed drawer, from 2012. Just to see if they were still viable, I arranged two sprouting chambers (~1 pint plastic boxes with tight-fitting snap-on lids), put a layer of cotton cloth in the bottom of each, and wet one with tap water (H2O), the other with 3% hydrogen peroxide (H2O2). I had several questions. Would any of them sprout? How long would it take, if they did? Would H2O2 prevent mold from attacking them while sprouting? Would H2O2 dissipate with time so as not to prevent sprouting?

The results: the H2O seeds sprouted nearly 100% after two days; the H2O2 seeds never sprouted.

Sweet Tatorman's picture

I too have seen some long viability in some of the cole species. I am current eating Florida broadleaf mustard from seed grown in 2008. I have also seen 10-11 year old Dwarf Blue Scotch kale do well.