Late last week, several weather-related organizations put out a release entitled "Major Cold and Wet Spring Event: Potential Impacts in the North Central U.S. April 26 –May 9, 2017." The story comes from the National Weather Service in partnership with NOAA, USDA Midwest Climate Hub, USDA Northern Plains Climate Hub, Midwestern Regional Climate Hub and the High Plains Regional Climate Center. Given the list of players, I tend to believe what they are saying!
The release covers April 2 through May 9. The highs are projected to be in the low to mid 50s, with lows between low 30s and high 30s. Those low temperatures threaten our flowers, some vegetables and fruit trees, and sensitive landscape plants. Gardeners can cover newly planted flowers and perennials about to bloom. Any of the fruit trees in bloom are at risk. Stone fruits like peaches are much more sensitive to cold temperatures than apples, but if a freeze occurs, any fruit tree in bloom will be impacted. There is not a lot we can do for larger landscape plants and trees.
Besides the recent rains, the 8 to 14 day prediction for above-normal wet weather for our area is greater than 40 percent. That is a statewide prediction. If the soils remain wet to very wet, and the temperatures do not rise much above 50 degrees, tender and warm season vegetables are going to be set back in development until things dry out and warm up. Seeds will be delayed in germinating and their fate will be tied to seed diseases that can attack and kill them before they even begin to germinate.
For fruit trees, lots of rain means those fungicide treatments will need to be re-applied to keep the young foliage protected from foliar diseases, and they will need to be more frequent as long the rains continue. Related to the cool temperatures and rain will be the need to mow the lawn, as this is a favorite time of year for grass. Mowing during times when the lawn is wet increases the chance of spreading disease and compacting the soil as the mower wheels move across the lawn along with the footprints from your shoes. Try to resist mowing as long as you can, hoping for a day when the grass is dry and all that excess moisture gets to drain away. Excessive rains also can leach any fertilizers already applied right out of the grass root zone, especially nitrogen.
Richard Hentschel is a Horticulture Extension Educator with University of Illinois Extension, serving DuPage, Kane and Kendall counties. Stay tuned to more garden and yard updates with "This Week in the Garden" on Facebook at facebook.com/extensiondkk/videos.