Agree with my-thyme. Spinach goes straight into the ground. When the weather turns cooler again in the fall, you can plant a 2nd crop of it. Beans need the ground to be warm; mid-May, definitely - straight into the ground. I grew up in Wisconsin, with a much shorter growing season and there was never any need to start beans inside. Cukes, tomatoes, peppers, eggplants, yes, because they require a longer growing season, but we've put even zucchini and other squashes from seed here in MD and had bumper crops.