Vegetable gardening season is nearly here now, and there are several vegetables that can handle cold or cool temperatures, both above and below ground. In fact, our early spring vegetables really need the cooler temperatures to develop properly. Right now, you can sow or plant those very hardy vegetables in the garden. These vegetables can withstand very cold to freezing temperatures, and typically go in the garden four to six weeks before our area average frost-free date. Some use April 30, others use May 5, and both are valid depending on where you live in northern Illinois.
Very hardy vegetables include kale, kohlrabi, leaf lettuce, onion, pea, rutabaga, salsify, spinach, turnip, broccoli, Brussels sprouts, cabbage, onion sets/transplants, parsley, Irish potato and rhubarb. You can see that this list contains vegetables that can be sown directly or put in as transplants. From this group you can easily find vegetables that the whole family will eat. You can plant successive plantings of leaf lettuce, radish and spinach every ten days or so for a continuous supply until the warmer weather gets here. If you are going to plant rhubarb, be sure it has a place out of the way since it is a perennial crop.
Once your very hardy vegetable seeds and transplants are in the garden, you can wait a couple more weeks before planting the frost-tolerant vegetables; those can withstand some frosty nights, but not an actual freeze. Beet, carrot, chard, mustard, parsnip, radish, cauliflower and Chinese cabbage make up this group of vegetables. Often times a retail outlet will be selling cabbage and cauliflower together. Be sure to wait to plant the cauliflower since frosty temperatures can be damaging. When planning, remember that some of these vegetables are short-term crops, such as radish, versus chard and parsnip, which are full-season vegetables. Plan to plant accordingly to make the best use of your garden space!
Another perennial favorite is asparagus. A planting of asparagus can last up to, or even beyond, 20 years. Sometimes it is better to establish asparagus in a bed all of its own or along with other perennial garden plants. Asparagus is typically established using one-year-old crowns as soon as your ground can be worked without damaging soil structure. Planting asparagus is a bit unique in that you will need to dig a wide trench about 15 to 18 inches wide and 6 to 8 inches deep. Crowns are placed with the buds upright and the pencil-sized roots radiating outwards. Spacing should be 10 to 12 inches apart. Cover the crowns with two inches of soil and fill in the trench as the season progresses. This will leave the crowns planted at the proper depth by the end of the season. As tempting as it is, do not harvest any of the spears the first season. Ditto for the very hardy rhubarb; wait for the second year for that pie.