Frequently Asked Questions

Frequently asked questions

by V.D. Jeliazkov, J. Noller, S. Angima, S. Rondon, R. Roseberg, S. Summers, G. Jones, V. Sikora (Oregon State University Extension Service)

Read original FAQ

  • Question: What are the differences between hemp essential oil and hemp seed (fixed, vegetable) oil?
  • Answer: They are very different products.
    Essential oils (aka volatile oils) are generally volatile organic substances produced by many types of plants that readily evaporate when exposed to air. They have a distinct, strong aroma that resembles the aroma of the plant from which it was extracted. Hemp essential oil is a complex natural product mix comprising around 140 individual constituents, including terpenes. The strong odors associated with hemp are primarily due to the terpenes; the cannabinoids such as THC and CBD have very little smell. Hemp essential oil and cannabinoids accumulate in the glandular trichomes, the epidermal hair-like structures on leaves and female flowers.
    The hemp seed (fixed) oil does not contain cannabinoids or terpenes. It contains fatty acids like other edible vegetable oils. The composition of hemp seed oil is comparable to other edible oils. It has a high concentration of polyunsaturated fatty acids, which is considered good for human health. However, the high concentration of polyunsaturated fatty acids makes it sensitive to oxidation rancidity. The degradation of hemp seed oil is accelerated by light, heat or bacteria, making hemp seed oil excellent table oil for salad dressing but unsuitable for frying or baking.
  • What is hemp oil? What is the oil content in hemp?
  • Industrial hemp contains fatty acid oil found in seeds and volatile oil found in flowers and leaves. The fatty acid oil content of seeds is about 30%.
  • What are the advantages of hemp fiber over other types of fibers?
  • Hemp fibers are naturally biodegradable and have other advantages over synthetic fibers, which are mostly fossil fuel-based.

Regulations/government support

  • Can I grow an industrial hemp crop legally in Oregon?
  • Yes, if it is grown and sold in compliance with the 2014 and 2018 federal farm bills. In Oregon, you also need a license from Oregon’s state agriculture department.
    When growing hemp commercially, it is advisable to source for certified seed. Oregon State University started certifying hemp seeds in June 2019.
  • Is it legal to grow and sell hemp?
  • Yes, if it is grown and sold in compliance with the 2014 and 2018 federal farm bills.
  • Does current law prohibit fiber and oilseed hemp with a high concentration of THC content?
  • Yes. Countries regulate how much THC can be in fiber and oilseed hemp varieties. The U.S. limit for THC is 0.3% in dried biomass. If above that, the variety of Cannabis sativa is considered marijuana.


  • Are there good cultivars for dual-purpose crops that provide high-protein forage and quality fiber?
  • Yes. Some varieties can be used as a dual purpose for grain and fiber production, but hemp is not an approved animal feed in the U.S.


  • What are the soils, fertilizers and irrigation needed for hemp production?
  • Industrial hemp can be grown successfully on a variety of soils, but it grows best in well-drained, fertile soil. Hemp does not tolerate very wet soils. Production issues caused by growth in wet soils can include low fiber quality and uneven plant heights, which present challenges at harvest. Generally, hemp requires more water than most field crops.
  • What are good cover or rotation crops to grow before or after hemp?
  • Industrial hemp fits well in rotations with wheat, barley, corn, alfalfa, potatoes and soybeans.
  • What nutrients and pH levels are required for hemp?
  • Hemp nutrient requirements are similar to those of spring wheat. While hemp nutrient requirements for a given soil and region may not be available, nutrient requirements for wheat are. We suggest you test the soil and follow nutrient guidelines for spring wheat.