Nevada weather is teasing us again with a few sunny, warm days followed by days of freezing temperatures. The warm days make me want to get my garden started, and I think, "Surely, it's time to plant kale, chard and other greens." I have to tell myself, "Wait!"St. Patrick's Day (March 17) is the traditional start date for cool-season gardens in Northern Nevada. Very hardy crops such as English peas, snow peas, sugar snap peas, cabbage, kale, broccoli, lettuce, spinach and turnips can be planted from seed mid-March through May 1. Onion seeds, plants or sets can go in, too.Semi-hardy …