Vegetables For Cool Season Gardening - Available At The Garden Center Now For Fall Planting. Did you know that some vegetables thrive in cool weather and really won’t do well in the summer heat? The cool season is an ideal time for growing vegetables. Choose from broccoli, arugula, collards, kale, kohlrabi, radish beets, leeks, bunching onions, turnips, lettuce (buttercrunch, green leaf, red-leaf, romaine), bunching onions and more. Within a few short weeks, you will have a basket or two of some of the healthiest leaves, root crops, and vegetables that Mother Nature can provide.