Some cool-season seeds like lettuce, spinach, and arugula are just better directly sown in the ground when the weather and soil conditions are right (March through early May). They are such quick growers there's no need to start them by seed indoors. If you have cold frames or similar to get started earlier, then you know what to do (don't forget to send me photos of your early lettuces please). It's much too early to plant warm-season crops outside, but it's time to start peppers and eggplant by seed indoors, they can take up to 8 weeks to fully grow into transplant size. I'll post a chart for flower seeds shortly, so please check back.
Vegetable Planting Calendar for the Colorado Front Range
Add at least 2 weeks for higher altitudes
For super earlier spring planting (using Tunnels, Cloches, Cold Frames), move up all dates accordingly
Document by Betty Cahill, http://gardenpunchlist.blogspot.com/