Mention the word hemp and you’re likely to hear someone draw an immediate comparison to marijuana. That’s because the two plants are actually two different cultivars of the same botanical species: Cannabis sativa.
But though they’re often thought of as two sides to the same coin, it’d be more accurate to consider hemp and marijuana as two cousins with very distinct personalities.
In this article, we’ll look beyond the skin-deep resemblance and shine a light on the many differences that set these two cannabis cousins apart.
Similar Looks, Different Effects
Take a quick look at a hemp plant and a marijuana plant growing side by side, and it’s easy to see the two strains are related. They both feature serrated, sharp-pointed leaves–generally with five to seven leaflets each–that are easy to pick out of any botanical lineup.
But like any two look-alike cousins, a closer inspection reveals a world of difference.
- Marijuana plants can be distinguished from hemp by being both shorter and bushier, with broader leaves and a preponderance of flowering buds.
- The stalks of industrial hemp plants are usually much taller–up to four meters in height–with thinner leaves and fewer bud-covered branches below the topmost reaches of the stalk.
- These differences stem from the fact that these two strains of the cannabis plant are usually grown for very different purposes: marijuana for its recreational, mind-altering effects; hemp for its fiber and oilseed, which are useful for more than 25,000 industrial and medicinal applications.
It’s All in the Chemistry
All cannabis plants contain a broad profile of more than one hundred compounds known as cannabinoids, which mimic the effects of similar chemicals already at work in the human body.
Throughout their long centuries of cultivation, the differing uses for marijuana and hemp have resulted in two strains of cannabis with very different cannabinoid profiles.
- The most widely renowned of the cannabinoids is undoubtedly tetrahydrocannabinol, or THC. That’s because it’s the main chemical responsible for the euphoric high associated with marijuana.
- But while marijuana always contains a relatively high concentration of THC–between 5 to 20 percent on average, and up to 30 percent for the most potent varieties–industrial hemp, by definition, contains extremely low levels of this particular cannabinoid.
- This negligible amount of THC means that hemp is non-psychoactive.
- In contrast to marijuana, hemp tends to contain higher levels of cannabidiol (CBD). CBD is the second most well-known and well-studied cannabinoid. And while THC heavily affects cannabinoid receptors in the brain, CBD interacts more broadly with receptors throughout the body, imparting a more generalized therapeutic impact on the body’s systems without the powerful psychoactive punch thrown by THC.
[Learn more about the differences between THC and CBD in this deep dive.]
Indoor vs. Outdoor Growing Environments–Different Plants, Different Preferences
Mirroring their contradictory natures, hemp and marijuana strains tend to thrive in very different settings.
Marijuana tends to pop up mostly in greenhouses or other indoor settings. That’s because like many heady, creative types who can only produce when the atmosphere is just right, marijuana strains produce the most THC when their growing environment is carefully managed to provide the perfect balance of ambient conditions and nutrient schedules.
Moreover, since pollination can reduce the potency of THC, many marijuana growers intentionally cull the male plants from their crop, a process that can end up requiring a lot of close inspection and time spent wandering among plants. The laboratory-like setting of a greenhouse is particularly well suited for these pampered proclivities.
Hardy hemp, on the other hand, can grow in a wider variety of conditions. The plant loves to get its leaves dirty in the great outdoors, and is highly suitable as a field crop.
You’re far more likely to see hemp sprouting up in more typical farmland fashion–on large tracts of land with tightly spaced rows.
In such settings, the close quarters help to encourage the growth of tall, fibrous stalks, while the vast acreages ensure a large enough crop for hemp to be harvested profitably as an industrial commodity. And with the recent passage of the 2018 Farm Bill, there are no federal laws hindering farmers from planting hemp across the United States, since it no longer falls under Schedule 1 in the Controlled Substances Act.