Although the photo is from May 29, these cold weather plants were seeded in the raised bed soil on April 29.
What you're seeing is 30 days of growth starting from April 29.
The raised bed soil was a mixture of earth (from the raised bed) and compost (from the landfill's composting of grass and leaves). The soil in the raised bed has been in the raised bed 2 years.
The first year, I simply built the wooden frame, laid down four layers of newspaper, and dumped in 4 inches of compost from the landfill.