I was late starting my seeds this year and I think it turned out to be a good thing. I planted on March 31st, April 7th and May 1st. My seedlings are stronger than they have ever been. I think I am not fighting the heat-war by starting them later. I don't have heat mats so I heat up my seedling room (it is walk-in closet size) with a portable heater. This year I only turned the heat on once but the seedlings look healthy and strong.
I almost transplanted last week, but I had heard that we were going to get a cold snap. I am so glad that I have held off. Pushing the season on the front end - unless you have a hoophouse and row covers - doesn't seem to pay off. The cool weather seems to stunt the growth.
And in typical fashion, I started too many. I think I have about 35 chard plants, at least 15 kale starts. Not to mention 25+ tomatoes. Oh my - I really need to move to a farm! I updated the side bar with the varieties and numbers.