GRAND RAPIDS, Mich. (WOOD) — After several thaws this winter, fruit and plant lovers across West Michigan have been concerned about our upcoming growing season, but experts say we are right on track for a good spring.
Newsradio WOOD 1300 AM and 106.9 FM’s garden and growing expert Rick Vuyst says the key to a good spring is to have a slow and gradual warm up. He says despite a few stretches of unusually warm weather this winter, spans of cooler conditions have put West Michigan right back on track.
For plants and bugs to wake up, air temperatures need to be around 50 degrees and the soil temperatures must be near 60 degrees. Vuyst says already this year WitchHazel trees and Hellebores have already bloomed and the Magnolias are close to blooming.
Since our temperatures fluctuate so much in the spring growers frequently monitor progress using “heating degree days” or “growing degree days.” This is based off of 50 degrees, and uses a small math equation. Growers take the daily high temperature and daily low temperature and add them together. Then they divide by two. However much is over 50, is considered a growing degree day. You can find the growing degree days using this website.
Here’s an example: Let’s say we have a day where the high is 64 degrees and the low is 44 degrees. Add those two numbers together to get 108 degrees. Divide it by two and you get 54 degrees. This number is four more than 50, so that day there is a total of four growing degree days added to the running spring total. This year and last year have accumulated pretty similar growing degree days.
Compare this to 2012 when we had massive crop loss and the heating degree days by this date were close to 200.
Our average last freeze usually arriving in late April and through the month of May depending on how far north a location is. Spots further north and further from Lake Michigan usually see frosts linger much longer in the spring than southern spots near the lakeshore. Here are the average bloom dates for West Michigan:
Now is the time to start planning ahead with crab grass killer and early bloomers. Vuyst recommends watching Redbuds, Ornamental Pear and Magnolias for an early show this spring.