Growing Hemp in Illinois

Begin Your Hemp Journey


Illinois is divided into three major sections, by land, the Gulf Coastal Plains, Shawnee Hills and Central Plains. Read on below to find out whether this state has the necessary conditions to support the cultivation of hemp.  

Plant Hardiness Zone(s)

The state of Illinois is divided into five different zones, ranging from 5a to 7b, as per the USDA plant hardiness map. Hemp, which is a zone 8 to 11 hardy plant, will likely not survive the low winter temperatures of this part of the country, and should therefore be grown during the summer when it’s much warmer.

Thermal Profile

The state of Illinois has a varying climate, mainly due to its length. The northern half of the state has a humid continental climate, while the northern half has a humid subtropical climate. While the northern part experiences cold or cool winters, the south experiences milder temperatures. The average annual temperature for the state is 51.3 degrees Fahrenheit. Hemp requires a minimum annual average temperature of 45 to 50 degrees Fahrenheit.

Length of Growing Season

The average length of the Illinois growing season is 170 days. The last frost days are in late April, while the first frost appears in October. Hemp plants take 120 days to grow from seedling to mature plants ready to be harvested. Even though exposure to frost will not impact the quality of the plant matter to be harvested, it can kill young plants.

Average Annual Sunlight

The state receives around 2,567 hours of sunlight each year. Hemp plants require a minimum of 12 hours of sunlight to grow to their maximum size during the vegetative stage; failure to which, the flowering stage is triggered.

Average Annual Precipitation

With the months of May and June marking the wettest period of the year in the state, the average annual precipitation increases from around 32 inches in the north, to around 48 inches in the south. Flooding is also a common weather hazard in this part of the country. An average of 25 to 30 inches of rainfall annually is enough to support the growth of healthy hemp plants. Exposure to extended periods of flooding can kill growing hemp plants.

Surface Elevation

The state of Illinois lies at an average height of 600 feet above sea level. The lowest point is at the Mississippi River, at 279 feet above sea level, while Charles Mound, standing at 1,235 feet above sea level is the highest point. Hemp plants should be grown at or below 600 to 800 feet above sea level.

Soil PH

Soil ph varies across the state from strongly acidic in parts of the southern region of the state, to slightly alkaline. Hemp grows best in soils with a pH of 6 to 7.5.

Soil Composition

Well-drained, aerated soils that retain moisture and nutrients well are best for growing hemp. Illinois is known for its wide variety of soils. However, most parts of the state have fertile but poorly to moderately-drained silt clay loam soils.

Notable Pests

In addition to the European corn borer, aphids, fungal bacterial and viral pathogens are the other common threats to growing hemp plants in Illinois.


Click here to read about how we calculate a state’s Hemp Hardiness Score.

Obtaining A Hemp Grower’s License In Illinois

Under federal law, it is illegal to grow hemp anywhere in the United States without first obtaining a grower’s license from the appropriate regulatory body for the state in which the interested party intends to plant the crop. For information on the legal status of hemp in Illinois, as well as a breakdown of the application process, click here.

Program Name Program Type Resources
Indiana Pilot Office of Indiana State Chemist & Seed Commissioner

Purdue University Hemp Project

Indiana Hemp Industries Association