USDA Illinois Hardiness Zones: 5a, 5b, 6a, 6b, 7a
Illinois is a consistently temperate state which sees all four seasons, from hot, humid summers to long cold winters.
In addition, the northeast area of the state, bordering Lake Michigan, receives lake effect snow.
The more southern portions of Illinois are warmer, with the temperatures cooling as you move towards the northern parts of the state.
Illinois faces an average of 32 tornados per year, most of them happening in the month of May.
It will occasionally see hurricanes and thunderstorms, wind, and hail, which can be damaging to gardens. The Illinois planting zones can you help you find out what plants grow best in your area.
Illinois Planting Zone – A Quick Overview:
- If you live in Illinois’s tiny, southernmost tip, you’ll be in the warmest zone, 7a.
- Other than the tip, the southern 1/4 of the state, including Murphysboro, is solidly in zone 6b.
- Moving a little bit north, if you live in the middle ¼ of Illinois, including Effingham and Charlestone, you will be in zone 6a.
- Most of the top half of the state, from Springfield north, is Zone 5b.
- If you live in Chicago, you might be in Zone 6a.
- But if you live in the north-western corner of the state, near Lake Michigan, you’ll be in the coldest part. So you’ll find yourself in Zone 5a.
Using the Illinois Growing Zones Map
The hardiness map for Illinois was created to help farmers and gardeners have successful gardens. It is based on the 2012 USDA map data.
Knowing your Idaho climate zone will help you understand which plants will grow in your area and when to plant them, helping you to have a more successful garden.
To find your Illinois gardening zone, just enter your zip code into the search bar or find your location on the map. The Illinois zones are fairly consistent, so yours should be easy to find.
Once you find your location, take note of the color of the map. This color corresponds to a color in the map key, which tells you your specific grow zone.
Of course, these zones are just guides and may be slightly different from what is actually happening where you live.
Differences in terrain, such as lakes, deserts, and elevation, can have an effect on the climate where you live, making it a little warmer, cooler, or more exaggerated.
If you aren’t sure, don’t be afraid to consult with local farmers and gardeners who can help you understand your local climate zone.
If you need to, you can adjust or create small micro-climate areas. For example, you can shield your garden from wind by planting it next to a building or boulders.
You can also plant hedgerows around your garden to shield it from some extreme weather.
Illinois: A Temperate State
Although the state has a four-season climate, there are a few shrubs and trees that you can enjoy year-round, according to Hoerr Nursery, including redtwig dogwood trees.
Winterberries, rhododendron, and even hydrangeas will add interest to your garden year-round, even when they aren’t blooming or growing.
Ornamental grasses, such as Miscanthus or Karl Foerster grass, also look great year-round.
On the other hand, vegetables can do quite well in Illinois as long as you plant them according to your hardiness zone.
Wait until your last frost date has passed to put most of your frost-tender plants in the garden. This can be as late as mid-May in many areas of the state.