Industrial Hemp as Forage for Honey Bees
Date: September 9, 2016
Author: Nick J. French
Bees and plants developed a symbiotic relationship starting 130 million years ago. The bees use the plant’s pollen and nectar as a source of food. In return the plant’s pollen, the male sex cells, are transferred on the body of the bees to the female sex cells on other plants (Goulson, Dave). In fact, honey bees add a huge value to agricultural food production around the world through pollination. Pollinators contribute $24 billion to the U.S. economy and honey bees contribute $15 billion (White House).
With this knowledge and beekeeping experience, Nick French, owner of Frangiosa Farms, began a research project in June 2015. He set out to be the first commercial beekeeper to attempt to increase the economic value of industrial hemp (Cannabis Sativa L.) and provide bees with additional forage to help fortify their honey reserves for winter.
Cannabis production in the U.S. has been banned since 1937 with the adoption of the Marijuana Tax Act. For the past 80 years, research and production in the U.S. has been non-existent and until recently only allowed in a few states across the nation.
The re-discovery of the healing qualities of cannabis in the U.S. and around the world has turned the black market drug dealing into one of the fastest growing and extremely profitable industries in the country. There is a growing body of evidence that phyto-cannabinoids interact with a newly discovered endocannabinoid system to help regulate, treat, and even cure some illnesses, symptoms, and diseases. Many people looking for alternative healing options to modern day pharmaceuticals are now turning to cannabis and more specifically the cannabinoids THC and CBD.
In order to obtain these cannabinoids in high enough concentrations, the cannabinoids must be extracted from the cellulose and other plant materials. The extraction process makes the cannabinoids more available for human consumption and increases the bioavailability in humans and mammals. Extracts are collected from the flower, stems, and stalks of the Cannabis Sativa L. species through a variety of extraction methods. The most commonly used are butane, alcohol, and CO2. There is also a large economic value of the extracted hemp to be used as ingredients in food, drinks, and nutraceuticals.
CBDA is the precursor of CBD. The presence of CBDA at this concentration observed in this research is very significant when compared to what is commercially available. CBD is commercially available in most U.S. states and around the world. The potential for honey bees to forage on hemp and gather cannabinoids and store it in the propolis is profound.
With this research project comes risk with potential loss of bees, time, and resources. There are already considerable risks in beekeeping alone. During the 2015-2016 season, U.S. beekeepers lost 44 percent of their colonies due to a variety of contributing factors including varroa mite, pesticides, and malnutrition (“Bee Informed”). Beekeepers invest considerable time and money to recover from losses and establish new colonies. Through nine years of beekeeping experience, French knows firsthand that establishing a new colony can cost about $500 each for equipment and bees. Still, this is a research project he chose to do.
This research project will evaluate if industrial hemp (Cannabis Sativa L.) can provide honey bees (Apis Melifera) with sufficient pollen and nectar to sustain the bees. At the beginning of this project, it is unknown if industrial hemp will provide bees with supplemental forage, lengthening the foraging season, to help bolster their food reserves for winter. Part of this project is to also determine if the bees, through their foraging, would transfer any of the cannabinoids or phytonutrients from the plant to the honey, pollen, or propolis.
As a beekeeper, French wants to bring this value to industrial hemp. That is what this research project set out to do.
In early 2015, industrial hemp seed was valued at more per pound than an ounce of gold. Seed prices were reported to be $4,000 to $10,000 per pound and sometimes sold individually for $10 a seed. U.S. regulations banned the importation of viable hemp seed and the increasing demand for seed by start-up hemp farmers created the perfect supply and demand storm. That is why French became determined to find a solution.
The Cannabis species of plants are primarily wind pollinated; however, wind can be infrequent and unreliable. Wind does not guarantee 100 percent seed set on all plants. French set out to maximize seed set and production by using honey bees to increase the rate of pollination. Even a small increase in seed production could result in hundreds of thousands of dollars to the hemp farmer. Increased seed production would also help offset losses due to birds and seed drop during harvest.
The economic value is easy to see. For example, if bees could increase seed production by one pound per acre on a 100 acre field of hemp, this could create an additional $400,000 of value to the farmer. At the most conservative estimate, an additional 100 pounds per acre at $500 per pound of seed could be valued at $50,000.
Twelve hives of honey bees were placed on approximately 70 acres of industrial hemp outside of Brighton, Colorado in the small farming community of Lochbue. This hemp farm is run by Mike Sullivan of Hemp Farm Colorado. Sullivan was in the process of developing and registering his own plant genetics with less than 0.3% THC by weight called Colorado Gold Hemp Seed.
Each of the hives had two deep hive bodies with 10 frames in each hive body. On average, each hive body contained eight frames of bees, brood at various stages of development, and honey stores. The volume of bees was estimated at 800,000 at the time of placement and expected to grow to nearly 1 million by peak of season.
The industrial hemp on this farm was planned in 36 inch rows with spacing varying from a few inches apart to 12 inches apart. Hemp is very drought tolerant and flooding irrigates the fields approximately three times during the season. The rapid growth rate of hemp creates a canopy over the ground in about 45-60 days eliminating the need to apply herbicides for weed control. The industrial hemp on Sullivan’s farm was observed to be grown using organic practices.
The following table outlines the series of activities and observations over the course of the research project.
Date(s) in 2015
July 12 – July 30
Pollination in action. Within one week of the hives being placed in the hemp field, bees visited hemp plants and landed on both mature and immature flower buds of the male plants.
Hives were inspected on average of two times per week. Honey supers were put in place on July 19. At the end of July, only three of the 12 hives showed signs of additional wax and comb production in the supers. This was a sign of preparations for surplus honey production. (See Figure 1)
Pollen collection started with a bottom hive-based pollen trap with sliding collection drawer on the side. Pollen was collected for a period of four weeks at a 50 percent capacity in a rotation of three 3 days on and three 3 days off to allow bees to self-regulate pollen intake to meet their nutritional needs.
Pollen production was high, producing approximately half of a quart (16 ounces) of pollen in four weeks from two hives. Coloration of pollen was either generally orange and white with flecks of purple or generally yellow and white with flecks of purple (See Figure 2).
In all 12 hives, the volume of bees seemed to have hit a plateau. This means that the number of bees had not increased or decreased significantly over the past 30 days. Approximately five hives appear to be decreasing in numbers for unknown reasons.
In order to encourage the bees to collect excess propolis from the hemp and surrounding areas, a special combination of propolis traps and special covers were installed.
All 12 hives were not producing sufficient honey to fill even one frame in one honey super. At this point in the season, there was not sufficient time for bees to produce any surplus honey production. Brood production is almost non-existent throughout all colonies with some capped brood remaining. There were some serious concerns about the survival potential of all hives. Supers were removed to encourage bees to fill the hive body to the maximum with honey in preparation for winter.
The bee numbers dropped again and it was suspected that a large number of bees were dying in the field while on foraging flights. There is no surplus honey to harvest and the only concern now is to salvage as many bees and hives as possible. Four weak hives are combined into two.
All hives are removed from the field and the hive weight is extremely low. This indicates there is not enough honey reserves to feed the bees through winter. Only six of the remaining 10 hives have any chance of surviving the coming winter.
Samples of pollen and propolis were collected and sent for laboratory analysis of potential cannabinoid potency and pesticide residue. There was not enough honey present in the hive to take samples for laboratory analysis.
Figure 1 - Hives placed on industrial hemp on July 12th, 2015
Figure 2 - Pollen collection from bees foraging primarily on hemp
Measurements are presented in milligrams per gram (mg/g) and percent by weight (percent).
Results indicated at total cannabinoid profile of 9.30 mg/g or 0.93 percent by weight. Three different forms of cannabinoids were measured in the propolis sample at contractions higher than 0.01 mg/g; Cannabigerol (CBG), Cannabidiolic Acid (CBDA), Cannabigerolic acid (CBGA). CBG was measured at 0.94 mg/g or 0.09 percent, CBDA 6.52mg/g or 0.65,percent and CBGA at 1.84mg/g or 0.18 percent. (See Figure 3).
Pesticide residue results indicated the presence of all 18 pesticides tested. The test was not for more than these 18 pesticides. Seventeen pesticides were at levels below the set limits. Daminozidebut pesticide was detected at 10 parts per billion (ppb) with a limit of 10 ppb.
Figure 3 - Propolis laboratory results: 2016-03-08
One 1 small bag of pollen collected from the bees that foraged on industrial hemp. Results indicated at total cannabinoid profile of 0.94mg/g or 0.09 percent by weight. A detailed profile indicated the presence of CBG at 0.20mg/g or 0.02 percent; THCA at 0.31mg/g or 0.03 percent; CBDA at 0.33mg/g or 0.03 percent; and CBGA at 0.11mg/g or 0.01 percent. (See Figure 4).
Pollen was not tested for pesticide residue. Further testing is planned.
Figure 4 - Pollen laboratory results
French concluded that Cannabis honey is just not possible. Cannabis, although rich in pollen, is naturally nectar deficient and since bees need an abundance of nectar to produce honey they will be forced look in other places to find it.
With the conclusion of this research project, French plans to test the following concepts and report future results separately:
- How much of an increase will bees have on seed set and yield through biological pollination? Bees are known to increase fruit, vegetable and seed production on many other species of plants.
- Will industrial hemp’s abundance of pollen provide additional forage for bees when other local forage is in short supply?
- Is it possible to produce sufficient amounts of honey to support beekeeping operations and surplus amounts of honey to support a wild forage hemp honey sales business? Hemp is generally nectar deficient, only producing small amounts of nectar.
- Is it possible that through the foraging of bees on hemp that some of these cannabinoids may transfer from bees to hive products? Industrial hemp produces many different types of cannabinoids including CBD and at much lesser levels, Tetrahydrocannabinol (THC).
- Is there sufficient demand and interest in the hemp farming industry to create a Colorado based pollination services business? Commercial pollination services require the large majority of U.S. bee colonies to be transported thousands of miles each year.
- Would the collection of pollen by bees minimize the amount of pollen drift? Marijuana growers are generally concerned with the crosspollination of hemp and marijuana since hemp has virtually none of the psychoactive cannabinoid THC.
Cannabigerol (CBG) is not considered psychoactive and is known to block the psychoactive effects of THC. It stimulates the growth of new brain cells in a process called neurogenesis. Neurogenic compounds are extremely rare, which makes CBG a very worthwhile subject for more research. CBG also is antibacterial, anti-tumor, and aids with insomnia. CBG is considered a ‘stem cell’ cannabinoid and can change into different cannabinoids, altering the overall effects of the plant. It is effectively impossible to overdose on CBG; it usually exists only in trace amounts in a processed plant, this makes the already very high LD50 of 22.44g/kg even less. CBG ,CBD, and the CBCs all share the same molecular formula but have a different structure.
Cannabidiolic Acid (CBDa) is one of the four possible outcomes of Cannabigerolic acid (CBGa) being processed into cannabigerol (CBG), Cannabichromic acid (CBCa), Tetrahydrocannabibolic acid (THCa), and CBDa. CBGa is processed into other cannabinoids by synthase enzymes and the CBDa synthase was first purified and isolated in 1996. Coincidentally, this was the same year California passed Prop 215 and became the first medical cannabis state.
Cannabigerolic acid (CBGa) is formed when geranyl pyrophosphate combines with olivetolic acid within the cannabis plant. Because of CBGa, all other medicinal effects of cannabis are possible. Cannabigerolic acid (CBGa) can be thought of as the stem cell cannabinoid, which becomes THCa/THC, CBDa/CBD, CBCa/CBC, and CBG. It does this through different types of biosynthesis, where chemicals combine to form new compounds to include THC biosynthase and the CBD biosynthase. Hemp strains of cannabis have higher amounts of CBG due to a recessive trait which may imply higher amounts of CBGa present in those strains as well.
Cannabidiol (CBD) is one of the most common non-psychoactive cannabinoids in the cannabis plant, occurring in the largest concentrations after THC and THCa. THC is psychoactive because it interacts with the CB1 receptor. CBD, on the other hand, has no interaction with the CB1 receptor and uses other receptor sites. In an interesting reversal of CBD’s ability to calm THC psychoactivity, there is a way to transform CBD into THC.
(Definition source: The Leaf Online at www.theleafeonline.com, 2016/08/24)
Nick French has been keeping bees since 2008 in urban farms and in backyards as a way to offset colony loses and to engage the community. He prefers the title “Bee Shepherd” as opposed to beekeeper. French manages about 60-100 hives in four (4) apiaries in and around Denver, Colorado. In local raw honey you will find the greatest health benefits including allergy relief, skin care, and digestive and immune support. French also conducts backyard beekeeping workshops, educational presentations to schools, garden centers, and to community supported agricultural projects.
French has a breadth of knowledge gained through his time and travels in the U.S. Marine Corps and through traditional education. His studies have included biology, tropical marine biology (Australia), microbiology, and finance. French is passionate about urban farming, using an integrative approach to growing vegetables, composting, backyard chickens, bees, and using a subterranean greenhouse to extend the growing season.
Marijuana Timeline, PBS 09/09/2016
Fact Sheet: The Economic Challenge Posed by Declining Pollinator Populations, US White House Fact Sheet, Dated: June 20, 2014
 Goulson, Dave. “The Beguiling History of Bees.” Scientific American (2004), 1 Jan 2017 https://www.scientificamerican.com/article/the-beguiling-history-of-bees-excerpt/
 White House, Office of the Press Secretary. “Fact Sheet: The Economic Challenge Posed by Declining Pollinator Populations” (2014), 1 Jan 2017 https://www.whitehouse.gov/the-press-office/2014/06/20/fact-sheet-economic-challenge-posed-declining-pollinator-populations
 Bee Informed, “Nation’s Beekeepers Lost 44 Percent of Bees in 2015-16” (2016), 1 Jan 2017 https://beeinformed.org/2016/05/10/nations-beekeepers-lost-44-percent-of-bees-in-2015-16/