That’s how the saying goes here in New England. I’ve sown my peas in my garden as soon as the soil can be worked in the spring for years with great success. In addition to peas, you can sow arugula, broccoli raab, radishes and onions. Sprouting the peas indoors before sowing by placing them on a moist paper towel for a days or two can speed the process, but I usually just sow them directly.
I also start some seedlings early indoors, including tomatoes. These will go under grow lights for several weeks until the weather outside is warm enough for them to be transferred to my unheated greenhouse.