How to Grow Hemp Seeds for CBD Oil
To learn how to grow hemp seed for CBD oil is truly a science in the United States. The federal legalization of hemp via the 2018 Farm Bill was a bright moment in hemp history with less than 0.3 percent THC will not get you high but also a mistaken belief that "hemp" is not considered cannabis. Hemp is a variation of the cannabis plant, and cannabis with less than 0.3 percent delta-9 THC is now legal in the U.S.
This is why we created the guide of where to legally grow hemp in 2021 for hemp farmers. The biggest concern is that some U.S. farmers, who may have never considered growing hemp, will now start learning to become hemp farmers. Specifically for growing hemp outdoors for high concentration of tetrahydrocannabinolic acid (THCa).
* Bomar Agra Estates has provided this how to grow hemp seed for cbd oil information for fellow hemp farmers, cultivators and processors in the industry solely for educational purposes. Bomar Agra Estates is not legally responsible for the outcome of your seeds and cannot assist nor give any growing advice based on your specific hemp needs in your specific state, we are available for consultation services as needed.
Hemp producers will need to decide on varieties based on the desired end product: fiber, grain, grain/fiber, or cannabinoids. Every hemp variety will have its own unique set of characteristics: short or tall, small or large seed, higher or lower cannabinoid content, different flowering times, and different nutrient requirements.
This includes CBD hemp varieties bred to exhibit high concentration of CBDa. Only female hemp plants will produce flowers with high contents of cannabinoids.
Hemp Temperature Conditions
The optimal temperature for hemp seed germination is 65-70°F. Lower temperatures will delay emergence. It’s best to plant after potential risk of late frost (e.g., mid-May or early June). Seed is best planted at a depth of 0.75-1 inch. For direct seeding, acceptable soil temperature at that depth for germination is 50°F.
Hemp grows best on loose, well-drained, well-aerated soil with a pH of 6.0-7.0. Consistency in pH level will allow the plant to better absorb nutrients. If pH becomes too alkaline (above 7.5) or too acidic (below 5.5), it will cause deficiencies of nutrients. Hemp does not do well in heavy clay soils due to higher calcium levels and greater water retention/saturation.
Hemp generally prefers semi-humid conditions with temperatures between 60- 80°F. Hemp does not react well to over watering but requires ample moisture during early stages. Excess rainfall will stunt growth and lead to smaller yields. During the plant’s life-cycle 10-14 inches of rainfall is optimal, but larger plants will require more water. Irrigation may be necessary depending on size and geographic location.
Hemp germinates best in a firm bed but is sensitive to soil compaction and soil crusting for the greenhouse we use Fox Farm Light Warrior Seed Starter. For the farm, we make sure the seed is planted in 2/3 in the ground. Good soil moisture is necessary for seed germination. Cracked or dull-looking cannabis seeds are not likely to germinate. Also review our hemp germination reports under the Certificate of Analysis section.
Hemp has different nutritional needs based on the stage of its life cycle. Nitrogen is recommended during vegetative stage (e.g., NPK ratio of 3:1:2), while phosphorus and potassium are recommended for the flowering stage (e.g., NPK ratio of 1:3:4 then tapering off to 0:3:4).
Hemp Plant Life Cycle
Hemp is an annual plant belonging to the small family of flowering plants called Cannabaceae. The lifespan of hemp grown outdoors is about 120 days: 30-60 days for vegetative growth and approximately 60 days for flowering time, varying by genetics.
Although hemp will grow well in Midwest soil, it’s important to note that hemp is not a native plant to the region or to the United States; it is indigenous to central Asia and the East Indies.
While Cannabis sativa plant is an important source of durable nutritious seeds, and medical extracts, the plant is poorly understood genetically. Unfortunately, due to past U.S. prohibition of the cannabis plant almost no U.S.-based agronomic research existed until 2015.
With that said, the planting calendar and nutrient recommendations below are for educational purposes only. Further fertility research will need to be completed to determine best practices.
Nitrogen and potassium uptake are greatest during the first two months of growth. Higher rates of potassium and phosphorus are needed during the flowering stage. Sources of micronutrients include dead plant tissues, compost, and manure. The breakdown of organic matter (i.e. roots and leaves) will add nutrients back into the soil. No-till and holistic soil building practices are encouraged for creating fertile soil.
Male vs. Female Hemp Plants
Contrary to popular belief, hemp plants are NOT male “marijuana” plants. Only female hemp plants will produce flowers rich in CBDa. Cannabis pistils, which are often referred to as “hairs” of the hemp bud, can help identify female plants early on. Female hemp plants will continue to flower, forming fragrant buds until they are pollinated or harvested.
Hemp grown for grain and stalks produces very little cannabinoid content— close to 0% THCa and 0% CBDa. However, the government classifies “hemp” as any hemp plant containing less than 0.3% delta-9 THC. Therefore, hemp breeders have been able to develop high-CBD, low-THC hemp plants while falling under the legal classification, and social construct, of hemp.
The hemp plants, from which most CBD is extracted, is not your typical industrial hemp grown for fiber or grain; genetically, they are different. Genes of the hemp plant fight to convert the precursor cannabinoid CBGa to either THCa or CBDa, and plants can be bred to exhibit dominance in either cannabinoid.
Male Hemp Plant
Hemp varieties will be grown from regular CBD hemp seeds, resulting in both male and female plants. While both male and female structures are needed to produce CBD hemp seed, a higher ratio of female plants is desirable to maximize the yield per acre. Normally, only female plants live to mature seed stage.
Hemp producers looking to grow cannabinoid-rich flowers should beware of males from neighboring grain or fiber crop. Pollen can potentially travel miles, seeding female plants close by.
Female Hemp Plant
Un-pollinated hemp female flowers will produce higher concentrations of cannabinoids and terpenes than pollinated flowers. When starting from regular seeds, male and female plants will occur almost equally but generally a higher ratio of females is desired. To limit the likelihood of producing male plants, CBD-rich varieties may be feminized, meaning the seeds were produced by female plants intentionally pollenated by another female (monoecious) plant.
Feminized hemp seeds are generally more expensive, but they will result in little to no males in a field. Sinsemilla is an unnatural state for cannabis so plants should be monitored closely.
Hermaphrodite Hemp Plant*
While hemp plants are dioecious, having separate sexes, it’s possible for female plants to grow pollen sacs which may then pollinate its own flower. Inducing female plants to grow male sex organs is a common breeding technique to produce feminized seeds.
*Monoecious or hermaphrodite plants may be desirable for seed production or dual purpose use. Dual purpose varieties are bred to produce both grain and fiber.
Hemp Seedling & Hemp Cloning
If you are anticipating a longer flowering period on a particular variety but have limited time due to seasonal changes, starting from hemp seedlings or hemp clones can be a good way to get ahead, skipping the germination and seedling phase. Growing from hemp seedlings can also be a way to catch up if you are starting later in the season (i.e. late June or early July). Hemp cloning can save time but also can ensure that your crop will be genetically identical to the mother plant.
When starting from clones, there will be transplanting involved. Transplanting is also a popular method when starting seedlings indoors earlier in the season when outdoor temperatures are not yet suitable for planting (below 60°F).
Starting from clones can be advantageous when growing CBD-rich varieties. Cloning essentially takes the guess work out of sexing plants and improves the odds of a hemp plant not “going hot”, or exhibiting a concentration of delta-9 THC higher than 0.3 percent.
When THC production genes are turned “on” and CBD is turned “off,” plants are THC dominant, psychoactive, and are considered recreational and medical. When both CBD and THC genes are turned “on,” plants are moderately psychoactive (as CBD potentially lessens the psychoactivity of THC) and are considered medical. When CBD production genes are turned “on” and THC is “off,” plants are considered industrial or food product.
Whether hemp varieties bred to produce high concentration of CBDa and low concentration of THCa will be more or less likely to go “hot” in more fertile soil is yet to be studied. Therefore, hemp seedlings and hemp clones of mother plants grown in local conditions or perhaps well-adapted to the local environment pose the least risk.
Outdoor Farm (CBD Biomass)
Opportunities for outdoor cultivation can substantially lower startup costs, but harvesting CBD-rich hemp is laborsome. Small hemp farms may need extra farmhands to harvest the crop in time. Proper spacing supports efficient harvesting.
Rows are typically 4’ x 4’ with 6-8 feet between rows depending on the variety. Hemp cultivated outdoors for CBD purposes will mainly be processed into biomass to produce CBD extracts.
Preemptive measures should be taken to reduce the risk of contamination, e.g., pesticide blow over, heavy metal contamination, or microbial contamination.
Indoor Greenhouse (CBD Flower)
Indoor cultivation facilities offer more control over the growing environment but can be more capital-intensive when using artificial lighting. However, indoor cultivation also includes sun-grown hemp in greenhouses or enclosed hoop houses, but its perfect for having plants make your CBD hemp seeds for next season.
Hemp CBD Plant Uses
While many industrial farms are preparing to grow hemp at large scale, there are many advantages to small-scale production. First, failing small is better than failing big.
Hemp cultivated for CBD-rich flower or biomass is generally more difficult to plant, upkeep, and harvest. Growing at large scale while maintaining high-quality will be challenging.
While most recreational hemp cultivators focus on high-THC, low-CBD chemovars (strains), hemp can be grown to reach high levels of CBD and low levels of THC. Hemp is a great option for those seeking to benefit from the hemp plant’s potential medicinal and therapeutic properties without getting high.
CBD Crude Oil
Crude oil refers to extract that closely resembles the cannabinoid/terpene profile of the original plant. CBD concentration tends to be between 40-50%. Crude oil is extracted via ethanol or supercritical CO2.
CBD Oil Distillate
Distillate with a higher concentration of cannabinoid content is produced using fractional distillation. Most terpenes and minor cannabinoids are lost in the refinement process.
CBD Oil Isolate
98-100% pure CBD. CBD must be isolated from decarboxylated, full spectrum plant material to create THC-free CBD products. CBD isolate is flavorless and water compatible.
Humidity, water saturation, lack of airflow, and excess foliage are likely to cause fungal diseases and microbial contamination to hemp plants. Gray mold and powdery mildew are the most common diseases caused by humid conditions and excess moisture. Hemp infected by mold, powdery mildew, and other fungi pose a potential threat to hemp consumers.
Mold should not be confused with the plant’s trichomes or the resinous glands that produce cannabinoids and terpenes.
Preventative measures include planting in areas with proper drainage and runoff (i.e. mounded rows), providing ample spacing for plants to grow and to improve air circulation, and proactively pruning plants to remove excess foliage. After harvesting, proper drying and storage of cannabis flowers to control humidity levels is extremely important.
Excess water may also cause root rot. In the Midwest, plasticulture is likely not necessary. With heavy rainfalls, raised beds with plastic ground cover are bound to cause over saturation and lead to beds drying too slowly.
- UNITED STATES DEPARTMENT OF AGRICULTURE, BUREAU OF PLANT INDUSTRY – CIRCULAR NO. 57.
- UNITED STATES DEPARTMENT OF AGRICULTURE – YEARBOOK OF 1913
- (ARKANSAS) UNIVERSITY OF ARKANSAS – UNDERSTANDING THE NUMBERS ON YOUR SOIL TEST REPORT
- (CANADA) ONTARIO, CANADA – GROWING INDUSTRIAL HEMP
- (INDIANA) PURDUE UNIVERSITY – HEMP PRODUCTION
- (INDIANA) PURDUE UNIVERSITY – MICRONUTRIENTS: FUNCTIONS, SOURCES AND APPLICATION METHODS
- (KENTUCKY) UNIVERSITY OF KENTUCKY – AN INTRODUCTION TO INDUSTRIAL HEMP AND HEMP AGRONOMY
- (KENTUCKY) UNIVERSITY OF KENTUCKY COLLEGE OF AGRICULTURE – HEMP HISTORY AND AGRONOMY 2018
- (KENTUCKY) UNIVERSITY OF KENTUCKY COLLEGE OF AGRICULTURE PRODUCTION – INDUSTRIAL HEMP PRODUCTION
- (MONTANA) FARMERS UNION – INDUSTRIAL HEMP PRODUCTION 101
- (NEW YORK) CORNELL UNIVERSITY – 2018 HEMP TRIALS FOR NEW YORK STATE GRAIN, DUAL PURPOSE, AND FIBER PRODUCTION
- (NEW YORK) CORNELL UNIVERSITY – INDUSTRIAL HEMP: FROM SEED TO MARKET
- (NORTH CAROLINA) STATE UNIVERSITY – INDUSTRIAL HEMP OPPORTUNITIES AND CHALLENGES
- (NORTH DAKOTA) NDSU – INDUSTRIAL HEMP VARIETY PERFORMANCE