Mine are started in the greenhouse as it has been too cold (just my opnion, if your plants are growing, great!!) to plant directly. Probably not until May 1st will I try it You could easily plant broccoli and peas now as they are a cooler weather loving veggie
Radishes do extremely well in the cooler weather (very hearty/frost resistant), and spinach is pretty good about it too. Our frost-free date isn't until May 20, but for the most part we're usually clear by ~May 1. On the nights that I know it's going to drop close to frost... I use old 2l bottles that have been cut off at the bottom to cover the peas and beans.
But yeah, I won't even think about putting in the peppers/tomatoes/etc until May 20. By putting the other stuff in early, the spinach, radishes, and leaf lettuce will all give me about 3 weeks harvest before they get replanted/replaced. But there definitely was a risk involved in regard to the temperature for planting as early as I did (Mar 20).