I started my Super San Marzano paste tomato seedlings in the middle of February. It took most of them a week or so to sprout. By the first week in March they were about 3-4 inches high, and the first true leaf started to peek out.
They haven't grown since.
I would think it was something with the variety, but the single Henderson's Pink and the two Kellogg's Breakfast I started a week later have been behaving the same way.
I have watered them normally. I have fertilized them a few times with kelp liquid fertilizer. I moved them outside when the weather was warm and sunny and moved them back inside when it got windy and cool again. I checked a few, their roots look normal.
This week I'm going to pot them up a size, and I will be potting them deeply so some of the stem is in dirt to promote even more root growth. But I'm worried as these little darlings should be ready to go in the ground in a month and they are still so tiny. Also, I believe my seedlings last year were way further along than these.