Spring is officially here, and you might be thinking about planting everything from flowers to vegetables and more.
As you contemplate what to grow this year, here's something you'll want to keep in mind. The plants that thrive best where you live might not be the same as the past several years - after the U.S. Department of Agriculture updated its Plant Hardiness Zone map in November.
The map shows the standard by which gardeners and growers can determine which perennial plants are most likely to thrive at a location based on the average extreme minimum winter temperature, according to the USDA.
In the Chicago area, a number of notable revisions were made to the map, which had previously been updated in 2012.
Under the previous version, a large portion of Cook County, as well as slivers of DuPage, Will and Lake counties, were listed in zone 6a, meaning the average extreme minimum temperature was 5 to 10 degrees below zero.
For a vast portion of central and northern Illinois north of Springfield, the extreme minimum was slightly cooler at 10 to 15 degrees below zero, placing the region in the 5b zone.
Local
However, there was one major holdout.
The far northwest corner of the state, mainly comprised of Jo Daviess, Stephenson, Carroll and Ogle counties, was deemed a 5a zone, which represents 15 to 20 degrees below zero.
Feeling out of the loop? We'll catch you up on the Chicago news you need to know. Sign up for the weekly Chicago Catch-Up newsletter.
The most recent map keeps most of Cook County in the 6a zone. However, unlike before, it extends 6a widely to cover significant portions of Lake and DuPage counties, as well as the majority of Will County.
Other than that, no notable changes occurred in the Chicago area, though small parts of some regions were moved into different zones.
A major shift did occur in central Illinois, however.
Under the 2012 map, most of central Illinois north of Springfield was listed in the 5b zone. A large number of counties previously included in that zone have shifted into 6a. As shown in the latest map, the majority of communities north of Peoria are in the 5b region - with a couple of major exceptions.
A small section of the northwest corner of the state is still in 5a, though that specific area has gotten smaller.
Illinois' zones and associated temperatures are listed below:
- 5a - 15 to 20 degrees below zero
- 5b - 10 to 15 degrees below zero
- 6a - 5 to 10 degrees below zero
- 6b - 5 degrees below zero to zero degrees
- 7a - Zero degrees to 5 degrees
