I'll start by going down your list and suggesting a few simple meals:
June 22 - Bok choy sauteed Asian-style with garlic, ginger, and soy sauce, perhaps with some mushrooms, and a handful of chopped garlic scallions on top. Or, bok choy in a hearty noodle and vegetable soup. Spinach, lettuce, radishes, and radish greens can all go in a spring salad with onion scallions. Or, braise radishes and radish greens in butter (or wine) and serve over pasta, rice, or another grain, drizzled with balsamic. Turnips and their greens can go in a soup or stew with other vegetables. Or, roast turnips and radishes with the garlic scallion bulbs (and onions and other root vegetables for a hearty side dish). Save the turnip greens for a simple saute with bacon, garlic and onion, drizzle with lemon juice or hot sauce in the end.
July 25 - Peaches, peppers, and summer squash are excellent on the grill. Carrots and squash can be roasted or used in a soup. Roast the beets and make a warm beet salad that you can dress with slices of orange, feta, walnuts, and a vinaigrette. Save one beet to use raw; peel and shave it (with a mandoline) and make a salad with thinly sliced beet greens and scallions (a warm dressing, like one made with bacon or pecans, helps wilt the greens a bit before serving). Use the remaining beet greens in a frittata or on a pizza. (By the way, my book has a recipe for beet and beet green pizza, as well as a shaved beet salad!)
August 17 - Roast the green beans and potatoes with balsamic for a nice side dish. Make skewers with the summer squashes, onions, and apricots for the grill. Eat the corn Mexican-style (slathered with mayo, chili powder, lime juice, etc) or grill the corn without the husks, then shave the kernels off and make a charred corn salad with peppers, onions, and a mustardy or tangy dressing. Make a Greek salad with the cucumbers, tomatoes, and onion (just add feta). Or, make quick pickles with the cukes.
September 15 - Throw the eggplant, squash, and tomatoes into a roasted ratatouille (recipe for that is in my book). Leftover summer squash can be used in bread, muffins, cookies, or cupcakes. Make a slaw with the kohlrabi, carrots, and cabbage. Or, make kohlrabi home fries. Try cooked cucumbers if you're tired of eating them raw (they taste just like zucchini). Melons can go into a fruit salad, or serve the muskmelon with prosciutto. If you can't eat all those ears of corn, shave off the kernels and make corn chowder. I think I see carrot greens in there - turn them into carrot top salsa! Winter squash keeps for a few months, but can be used in roasts, soups, stews, and curries through fall and winter.
October 19 - I see a lot of things here that can go into a hearty vegetable soup and be frozen for quick weeknight dinners. For all those beets, here are a few ideas: roasted beets (can be used throughout the week in various cold and warm salads), beet chips, ginger beet puree, beet hummus, beet brownies, borscht, beet kvass. If you can't eat all those plums raw, turn them into jam. Apples can go into pancakes, Dutch babies, pies, or monkey bread, or make a chutney with them.
I'm often asked what spices go well with what vegetables, and honestly, I think it's easiest to cook from recipes until you find the combinations that taste best to you. Knowing how different herbs and spices work with different meats and vegetables comes from practice in the kitchen!
I can't imagine putting it all in a chart because the method of cooking greatly affects how an ingredient will taste (not to mention the infinite number of global cuisines you can pull inspiration from).