Southwest Michigan vegetable update – May 20, 2020
Excessive rain stops activity on most vegetable sites.
Temperatures for the week at the Southwest Michigan Research and Extension Center ranged from 62 to 72 degrees Fahrenheit for highs and 39 to 58 F for lows. The 50 F degree-day units are at 185 for 2020 compared to 200 for 2019 and 299 for the five-year average, keeping 2020 the coolest year out of the past five. It was an extremely wet week with 3 to almost 5 inches of rain being reported across the area (see figure below). Soil temperatures are averaging near 60 F.
Replanting from the recent freezes was carried out May 12-13 but came to a stop May 14 with the rain. Rain again occurred May 17-18 and many fields remain too wet to work or plant as of May 20.
Excessive rains reveals one of the downfalls of plasticulture production. Approximately 60% of the surface area is covered with water impermeable plastic, leaving 40% of the surface to absorb water. With heavy rains, even sandy sites have trouble with this much water. Each raised bed also creates a dam that prevents water from naturally draining off the surface. Sometimes this leads to water working its way over or under the plastic causing erosion or growers intentionally breach the plastic so water can drain (see photo at beginning of article).
Asparagus harvest has resumed after the temporary halt from the freezes. Full production should resume later this week and certainly by the weekend.
Direct seeded cucumber, zucchini and yellow squash are putting out their first true leaf.
Sweet corn planting continues where the ground is dry enough for planning activity to occur. Sweet corn producers need to consider adding additional nitrogen with their next application. Heavy rains would have leached preplant applications
No significant insect or disease issues to report in any crops at this time. The only problems are below normal temperatures and excessive rainfall.