Growing Hemp in Colorado

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A GUIDE TO GROWING HEMP IN COLORADO

Colorado has a diverse landscape that includes mountains, ranges and plains. If you are interested in growing hemp, read on to find out whether the state has the necessary conditions to support the growth of high quality crops.

Hemp is ideally grown outdoors, though greenhousing and transplant is also a viable approach for certain cultivars.  

Colorado soil boasts a high alkaline profile, making it well-suited to hemp cultivation. Farmers should aim for a soil pH level of at least 6, though target levels of between 7.0-7.5 are preferable.

Plant Hardiness Zone(s)

Colorado is divided into several zones, ranging from 3a to 7a, as per the latest USDA plant hardiness map for the state. Hemp is hardy to zones 8 to 11. Planting these plants at the right time will help minimize any risk of winter temperature inflicted damage or losses.

Thermal Profile

Unlike most states the southern parts of the state are not generally warmer than the northern parts. The Eastern Plains of the state have a semi arid climate. In these parts the nights tend to be cool and clear while the days are sunny. The climate gets more complicated heading west of the plains, around the foothills. While most valleys in this part of the state have a semi arid climate, higher elevations, right next to them, have an alpine climate. To make things more interesting, some areas have unique local climates, such as humid continental, sub-arctic, humid subtropical, Mediterranean and subtropical highland.

Length of Growing Season

The annual growing season in Colorado lasts an average of 120 days. This marks the period between the last and first frost. Hemp takes about 120 days to grow from seedling to mature plants that are ready for harvest. Frost usually kills hemp plants, regardless of their age. Growers in this part of the country need to perfectly time their planting season to ensure that their hemp crops are not killed by the often severe Colorado frost.

Average Annual Sunlight

The state of Colorado receives a lot of sunshine, with about 300 sunny days each year. Hemp plants need more than 12 hours of sunlight each day during the high growth vegetative stage.

Average Annual Precipitation

Colorado receives an average of 15.47 inches of rainfall each year. Most farmers irrigate their farms to meet the minimum water requirements of their crops. Since hemp requires a minimum average of 25 to 30 inches of rainfall, irrigation is necessary. Hail storms are a common occurrence in the Colorado plains, and a huge threat to growing hemp plants.

Surface Elevation

Of all the 50 states, Colorado has the highest mean elevation, standing at 6,800 feet above sea level. The Arkansas River is the lowest point in the state at 3,315 feet above sea level. High altitudes are said to stress hemp plants, and it is recommended that they should not be grown higher than 600 to 800 feet above sea level.

Soil PH

Due to limited rainfall, the state of Colorado mainly has alkaline soils with a pH of 7 or higher. Hemp plants grow well in soils with a pH of 6 to 7.5.

Soil Composition

The roots of the hemp plant tend to penetrate deeply into the ground, enabling the plant to access a greater water supply and larger nutrient stores than many other crops. It can grow anywhere in Colorado except for the deserts, but farmers may still need to employ irrigation systems in areas with lower annual precipitation levels.

The soil in most parts of the state is heavy red clay. This soil usually needs to be treated to increase its permeability and drainage. Hemp grows best in permeable, well-drained soils loamy soils.

Notable Pests

In addition to viral, fungal and bacterial pathogens, hemp plants grown in the state also face the threat of European corn borers and aphids among others.

HEMP HARDINESS SCORE:

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

Obtaining A Hemp Grower’s License In Colorado

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 Colorado, as well as a breakdown of the application process, click here.

Program Name Program Type Resources
Colorado Commercial Colorado Department of Agriculture Industrial Hemp Program

Colorado Hemp Industries Association