Cool-Season Vegetable Gardening
While many Iowa gardeners plant their vegetable gardens over Mother’s Day weekend, there are many cool-season vegetables that can be started much sooner. Unlike the tomatoes and peppers we plant in mid-May, these cool-season edibles do better in cool spring weather and suffer once Iowa’s hot, humid summers arrive.
Potatoes and onions, for example, should be planted as soon as the ground can be easily worked—usually early April. Beets, Swiss chard, carrots, lettuce, spinach, and peas also do well in cool temperatures. Early plantings of these also allow for successive plantings and a longer, larger harvest.
Other edibles that prefer cool weather include members of the Brassicaceae family: broccoli, cabbage, cauliflower, kohlrabi, and Brussels sprouts. Often referred to as the cole crops, they should be planted in mid-April from established seedlings started indoors or from a local greenhouse. Other Brassicaceae family members—collards, kale, turnips, and radishes—can be started from seed directly in the soil in early- to mid-April.
— Aaron Steil, Manager of Public Programs