Here’s what last year’s lettuce looked like when germinated and ready to be transplanted into bigger pots
Greens/lettuce seeds started inside February 8
Yesterday I planted some lettuce and greens seeds. Here’s how I do it:
I cut this tray into thirds
I bought these flats above for starting seeds indoors and under lights. I cut them into thirds as I like I them a little smaller as they are easier to handle and not so flimsy.
I like shallow containers to start SMALL seeds as it is easier to get the correct soil temperature needed for germination and I can plant a lot of seeds in a small space. Bigger pots for small seeds are harder to get the soil temperature correct. Optimal seed germination temperature for greens and lettuces it is 65-70 °F and it should take between 7-10 days to germinate.
I mark each row every inch and plant a seed there
Before I put in the seeds, I marked each row with a dot (I used a silver sharpie) one inch apart so I could evenly space the seeds and that way I can also see if a seed germinated by that dot. I use Metro Mix 360 soil for starting seeds. I pre-moisten the soil.
Put kiddie (play) sand on top after putting seeds in rows.
I used a pencil to make a small hole in the Metro Mix and put a seed in it. Afterwards I put ‘kiddie’ play sand over each row to cover the seeds and pat it down. Small seeds can easily break through the sand when germinating. I would use bigger pots for larger seeds. You must keep the soil moist at all times till they germinate. Because the trays are so shallow, I only have to mist the pre-moisten soil with a sprayer, sometimes several times a day. You could put a clear top on it till germination happens. I never put the trays under a faucet to water as that could move the seeds around.
Here I have them sitting on a heat mat but I don’t turn the mat ‘on’. For greens/lettuces I put the probe in the soil to see what temperature it is at with the thermostat. I find for greens/lettuces the lights above the seed trays provide all the heat needed to stay in that temperature range. Here the thermostat reads 66°F. I’ll turn seedling heat mats on later for warm season crops like tomatoes which like the soil temperature much warmer for germination. The thermostat is great for controlling the temperature.
Write down what variety each row is in a notebook
I identify each row with a number and then keep a record of what each number represents instead of trying to write down what it is on that little piece of tape. There are 12 dots so that means since there are 6 rows in each ‘mini-flat’ that there are 72 seeds in this tiny space! After they germinate and their first two true (cotyledon) leaves appear, I will transplant them each plant into a 4 pack and from there directly into a cold frame, low tunnel or greenhouse. Still too early to throw them outside without protection.
Here is what I planted:
1-Yugoslavian Red lettuce-butterhead type
2-Santoro lettuce-butterhead type
5-Baby Pak Choi
6-Forellenschuss (trout) lettuce-romaine