Coming in 4th for the top 10 states growing hemp is Kentucky. With a whopping 6,700 acres of hemp crops, it’s no wonder this state has made it to the top 10. Per their state laws for growing hemp, the crops must register at or below 0.3 percent of THC to be considered legal. Kentucky boasts a moderate climate with all four seasons and the soil is comprised of heavy and shallow soils so it can be challenging at best to find proper drainage without prior planning for gardeners in the Kentucky region.
Plant Hardiness Zone(s)
Kentucky has plant hardiness zones ranging from 5a to 6b. These zones are conducive to hemp cultivation however planting should take place in the warmer summer months.
The state is located in the southeast of the U.S. and falls in the South Temperate Thermal Zone meaning that it has cool to warm temperatures. Hemp prefers warmer air and soil conditions and temperatures in the summer months are therefore most suitable.
Length of Growing Season
The optimal growing season for hemp runs from late spring to late summer – May to August. Cultivation should take place when soil temperatures have reached between 42 and 46 degrees F. Germination takes place in 3-5 days after planting seeds and the plants should grow an average of 7 cm to 10 cm per day in optimal conditions. The last phase of maturation occurs when days are shorter than 12 hours. Harvesting should take place around 7 to 8 days after maturity has been reached. On average, hemp takes 110 days to reach maturation from germination.
Average Annual Sunlight
Hemp grows best when it is exposed to at least 12 hours of sunlight.
Kentucky receives, on average, approximately 2,577 hours of sunlight. 58.8% of daylight hours are sunny. Hemp is heliotropic and therefore requires maximum sunlight and should therefore be planted in the summer months when the largest amount of sunlight occurs in the state.
Average Annual Precipitation
Kentucky receives an average of 50 inches of rainfall annually which is optimal for most types of crops and should easily meet the 10 to 12 inch requirements of the hemp plant in the summer growing season. However, heavy rainfall, especially in the early spring, can result in compacted soil which is not ideal for hemp cultivation. Excess moisture can also be detrimental resulting in mold and fungus affecting the plant and the flowering heads.
The lowest elevation in Kentucky is 257 ft above sea level at the Mississippi River with the highest point of 4,139 at Black Mountain where the state borders Virginia and Tennessee in the southwest. High elevations resulting in colder temperatures may affect hemp crops but this is unlikely to be problematic in the summer growing season.
The soil used should have an alkaline level that lies between 6.2 and 6.5. Studies are still being conducted to determine which growing conditions are likely to yield the highest ratio of seeds to harvested plants.
Kentucky has the ideal soil pH level for hemp cultivation which falls between 6 and 7. However, some areas may differ slightly and soil testing is recommended.
Kentucky hillsides consist primarily of Baxter soil which is fine textured residuum. Maury soil in the woodland areas is also loose and drains well. Crider soil which makes up the majority of farmland in the state provides a combination of red and brown silt in top of a red loam layer of clay. All three soil types are suitable for hemp cultivation and allow for the development of a long tap root to reach nutrients contained in the deeper layers of soil.
Early insect seasonal pests include the flea beetle, squash bugs and brown stink bug. These pests affect different types of crops in Kentucky and it is largely unknown how they will affect hemp plants. However, hemp is prone to mites and aphids especially on the flower heads in the later growth cycle.
Obtaining A Hemp Grower’s License In Kentucky
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 Kentucky, as well as a breakdown of the application process, click here.