Growing Hemp in Missouri

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A Guide to Growing Hemp in Missouri

 

If you are thinking about growing hemp in Missouri, read on to find out whether the state has the necessary conditions to support a bountiful harvest. 

Plant Hardiness Zone(s) 

According to the USDA plant hardiness map, the state of Missouri is divided into 4 different zones. These are 5b in the northern part of the state, 6a and 6b in the central region and 7a in the south. Hemp is a zone 8 to 11 hardy plant.  

Thermal Profile

The climate of Missouri varies between humid subtropical in the southern region and humid continental in the north. Since cold winds blowing in from the arctic and warm winds from the Gulf of Mexico influence the state’s climate, the northern part is colder than the southern region. The average annual temperature in the state is 55.25 degrees Fahrenheit. 

Length of Growing Season

The average length of the growing season in Missouri is 180 days. The last frost disappears as early as mid-April, in some parts, while the first frost appears in October. Hemp’s growing period from planting to maturity is around 120 days long. 

Average Annual Sunlight

The state of Missouri receives an average of 2,690 hours of sunlight. Hemp plants need more than 12 hours of sunlight, each day, during the vegetative stage to grow to their maximum size. Once the days become shorter than 12 hours, the plants automatically transition into the flowering stage. 

Average Annual Precipitation 

The state receives an average of 43.11 inches of precipitation annually. The wettest month of the year in this part of the country is May, while January is the driest. Hemp needs a minimum average of 25 to 30 inches of rainfall annually. Even though the plant is considered to be drought resistant after it is fully grown, it needs the lion’s share of this annual requirement during the earlier stages of growth.

Surface Elevation

The mean elevation of the state is 800 feet above sea level. The lowest point in Missouri is at the St. Francis River, standing at 230 feet above sea level, while Taum Sauk Mountain, at 1,772 feet above sea level, is the highest point. Elevations below 600 to 800 feet above sea level are the best for growing hemp. Growing the plants are higher elevations subjects them to unnecessary stress that can negatively impact their growth or chemical composition. 

Soil pH

Most soils in the state are acidic. This means that to support the goring of hemp, which requires a pH of 6 to 7.5, liming might be necessary. 

Soil Composition

Missouri has a variety of soil types. The north and northeast regions of the state have heavy and poorly drained Kickapoo and Dockery soils. The Mississippi and Missouri river valleys on the other hand are known to have well-drained, moderately permeable soils. These deep soils are classified as Menfro, the state soil of Missouri. They are a silt loam variety that has very low proportions of clay. Hemp should be grown in aerated, well-drained loamy soils that retain nutrients and moisture well. 

Notable Pests

As is the case in most parts of North America, borers are among the common pests that pose a threat to hemp crops in the state.

Obtaining A Hemp Grower’s License In Missouri

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. View our breakdown of the 2018 Farm Bill for more information on the legal status of hemp in Missouri, as well as a breakdown of the application process.

 

Program Name Program Type Resources
Missouri Pilot Missouri Department of Agriculture Industrial Hemp Pilot Program

Missouri’s Industrial Hemp Pilot Program Begins to Sprout