Dan Fillius
Field Specialist, Commercial Vegetables and Specialty Crops
Iowa State University Extension & Outreach
[email protected]
For much of Iowa, mid-May means that there is little chance there will be another killing frost. Many people feel the call of warm evenings (or Mother’s Day) and decide to plant the first warm-season crops, such as tomatoes, peppers, and cucumbers. This year the weather seems to be behaving itself and as of May 9th, the time of this writing, the 2-week climate outlook is calling for greater chances of above average temperatures statewide. Let the “growing season” begin!
I place the words “growing season” in quotation marks because many crops have been growing quite well throughout all the cold snaps that have happened this spring - think lawns greening up, daffodils, tulips, and all manner of other plants that have emerged from their slumber in the past 2 and a half months. One doesn’t need to exclude vegetables from this category, spring seeded lettuce mixes and arugula have matured and been harvested once or twice, peas are knee high, and carrots, beets, radishes, and parsnips all have been planted as well. And this is a small sampling of the crops that farmers and gardeners have put in the ground.
The spring started out fast! For many of us, parts of February seemed like late March and perennial fruit farmers were very concerned that they wouldn’t get a crop this year. Thankfully the temperatures turned much milder, and those fears didn’t materialize. In fact, the past month or two have been ideal for plants that love cool conditions. Moreover, we’ve had abundant rains across the state to water in crops. So much rain, though, that there have been few windows of time to get some crops into the ground!
Weeds are also loving the rain, and it takes dry soils to control weeds mechanically, so some growers are falling behind on cultivation. Early weed control has an outsized impact on the development of a vegetable crop. Much like early childhood nutrition can strongly influence human growth potential, the same can be said about early weeding and fertilizing of a crop. The water is there, but can growers prevent the weeds from encroaching too far? I will be interested to see how spring-planted crops look in early June - that is, I am interested to see how stout the weeds are looking at that time!
Wet soils have also supported the development of root maggots in some onion crops recently. I will not be surprised to hear about other crop losses to this pest before the end of May. With warming soils comes a decrease in root maggots, so we are nearly out of the woods, so to speak.
All in all, this spring has the potential to produce a very lovely crop of lettuce, peas, spring carrots, kale and chard, kohlrabi, radishes, salad turnips, arugula, cilantro, strawberries, and more. Additionally, the plentiful rains have chipped away at long-term soil moisture deficits, enough to make me cautiously optimistic for the growing season in general!