How and Why to Grow Cannabis Microgreens
Ever thought of cannabis or hemp as a superfood? Recent research suggests cannabis can provide exemplary nutrition with a side of anti-inflammatories. Even better, you can grow these healthy microgreens in just 10 days.
What do you think of when you read the word “cannabis?” Most of us likely visualize an image of large mature plants with branches bending under the weight of resinous colas. Most growers cultivate the plant for female flowers that ooze cannabinoids and terpenes, after all. But as one of the most versatile species on the planet, and one humans have utilized for thousands of years for a long list of purposes, cannabis offers more than buds.
Cannabis seedlings are often viewed as a means to an end. Watching baby plants emerge from seeds induces excitement at things to come, but they’re rarely seen as a botanical product themselves. However, the concept of microgreens might change the way we view these small green shoots. Microgreens are skyrocketing in popularity because of their nutritional status, rapid turnaround, and simplicity. Broccoli, radishes, sunflowers, and peas are amongst the most popular microgreen options, but cannabis offers something these flavorful species don’t: small concentrations of cannabinoid acids and flavonoids seldom found elsewhere. Below, you’ll discover exactly what microgreens are, what makes them unique, and how to grow them yourself at home in approximately 10 days from seed to harvest.
What Are Microgreens?
Microgreens are essentially seedlings. They differ from other stages of plant development based on harvest time. They’re older than sprouts—a product harvested a matter of days following germination—yet younger than baby greens, plants that possess more true leaves and are ready to pick and process around four weeks after germination. Microgreens occupy the middle ground between these stages of growth. By definition, they stand between one to three inches and feature three main components: A stem, a set of cotyledon leaves, and a set of first true leaves.
More than just an aesthetic garnish used in restaurants, microgreens have surged in popularity because of their long list of impressive traits. Studies show many microgreens species offer much greater quantities of beneficial bioactive molecules than their mature counterparts. For example, cilantro microgreens possess three-fold the beta-carotene content of older plants. Red cabbage microgreens offer 28-fold higher concentrations of lutein and zeaxanthin—two plant pigments that protect eye health—than mature plants. Carotenoids aside, several microgreen species also outperform older plants when it comes to minerals; broccoli microgreens house more than twice the mineral content, including phosphorus, magnesium, and zinc. Because microgreens pump out such high levels of beneficial bioactive molecules, researchers are currently exploring how they might influence inflammation, immunity, and the microbiome.
Not only do microgreens offer superior nutritional value in some cases, but they take less of a toll on the environment. They don’t require pesticides or fertilizers, they have much less of a demand for water, and they’re ready to harvest far sooner; broccoli microgreens take 93–95 percent less time to grow than mature plants and require approximately 200 times less water.
Cannabis as a Leafy Green Vegetable
Does cannabis have a place as a leafy green alongside lettuce, spinach, and kale? Much like cannabis, all three of these species eventually go to flower. However, we choose to use them during the microgreen and vegetative phases for their nutrient-packed foliage. While most cannabis growers dedicate their seeds to the cultivation of mature flower-bearing plants, the microgreen format also boasts some attractive properties.
If you’ve ever handled a cannabis flower, you’ll have noticed a sparkling frosty layer on the exterior. Known as glandular trichomes, these translucent structures appear in various forms, including the iconic mushroom-shaped capitate-stalked trichomes. During the growing cycle, trichomes are tasked with manufacturing an array of secondary metabolites, including terpenes and cannabinoid acids. These molecules fulfil several important functions, such as defending against predation and UV rays.
Trichomes are most abundant on cannabis flowers, but also occur early on in the growing cycle on the surfaces of cotyledons and first true leaves, meaning microgreens also offer the secondary metabolites produced by these structures. Research conducted by Louisiana State University found cannabis microgreens possess an average cannabinoid content of around one percent.
In raw cannabis, the cannabinoids most of us are familiar with, including THC, CBD, and CBG, exist in their acidic forms THCA, CBDA, and CBGA, respectively. While all three of these cannabinoid acids have a low affinity to the receptors that make up the endocannabinoid system—the universal regulator of the human body—studies show they activate receptors belong to the expanded endocannabinoid system, known as the endocannabinoidome (eCBome). For example, THCA, CBDA, and CBGA bind to eCBome receptors known as PPARs where they reduce insulin resistance and exert neuroprotective effects. CBDA also appears to produce anti-inflammatory effects by inhibiting the enzyme COX-2, the same protein targeted by non-steroidal anti-inflammatory drugs. While cannabis microgreens contain only trace quantities of these compounds, the manner in which these concentrations tweak the eCBome in humans remains unknown.
Alongside cannabinoids, cannabis also produces flavonoids—phenolic compounds known for their antioxidant effects. As well as producing common flavonoids such as kaempferol and quercetin, cannabis also assembles rare flavonoids known as cannflavins that show up as early as the seedling stage. These molecules have demonstrated an array of beneficial effects in early studies, including anti-inflammatory activity 30 times that of aspirin.
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How to Grow Cannabis Microgreens
Now that you’re aware of the potential benefits of cannabis microgreens, it’s time to learn to grow them. If you’ve ever purchased cannabis seeds, you’ll know things can get pretty expensive. However, hemp seeds provide a much cheaper option. “Cannabis” and “hemp” are two names for the same species. “Cannabis” often refers to selectively bred drug-type cultivars that produce high concentrations of cannabinoids and terpenes. In contrast, “hemp” denotes fiber-type cultivars primarily bred and grown for stalks and seeds. Hemp seeds are considerably less costly than cannabis seeds, and the cannabis microgreen research mentioned above featured the analysis of hemp cultivars. With nomenclature out of the way, follow the steps below to secure your first crop of cannabis microgreens.
Before we get into the key details, you’ll need the following to grow your own cannabis microgreens:
- 100g of non-sterilized hemp seeds
- Bowl or jar
- Seed tray with drainage holes
- Collection tray
Step 1: Prepare Your Hemp Seeds
To grow cannabis microgreens, you’ll need to purchase non-sterilized hemp seeds. Some manufacturers heat-treat their seeds to prevent germination at the consumer end. Once purchased, measure out 100g, pour them into a bowl, and soak them in non-chlorinated water. Chlorine exerts an anti-bacterial effect. Hemp seeds possess endophytic bacteria that help in the formation of root hairs. If you’re using tap water, simply let it sit for 24 hours to allow the chlorine to off-gas. Leave your hemp seeds to soak overnight.
Step 2: Fill Your Grow Tray
The next day, pour your hemp seeds into a sieve to strain the water. Fill a shallow seed tray with two to three inches of soil (a fine potting mix will allow the taproots to gain a quick foothold). Spread your soaked seeds as evenly as possible on the surface and gently firm them down with the back of your hand. Give them a mist to moisten the soil and place the seed tray on top of a collection tray to contain leaks. Place your trays outdoors in the garden or under grow lights indoors.
Step 3: Lighting and Watering
Your young plants will require at least eight hours of direct light each day to ensure fast and healthy growth. Increased light exposure will also help to maximize cannabinoid acid content. Keep your trays in a sunny spot in your garden. The heat of a greenhouse will help to speed up germination. If you’re growing indoors, aim to keep your trays under grow lights for up to eighteen hours each day to prevent leggy seedlings. When the soil appears visibly dry, administer water from below using the collection tray to avoid getting foliage wet which can increase the chances of damping off.
Step 4: Harvesting Microgreens
Get ready to harvest your crop approximately 10 days following germination. You’ll know they’re ready to chop when the second set of true leaves are only just visible. Use a pair of scissors to cut them just above the soil surface. Keep your remaining microgreens rooted in the soil as a form of living storage and use them on-demand.
All things healthy typically share a common trait: They don’t satisfy the modern sugar-centric palate. You can eat cannabis microgreens straight, but they go down much better as a salad garnish or with fruit in a smoothie. Enjoy every bite or sip knowing you’re stimulating your eCBome with cannabinoid acids and nourishing your body with potent cannabis-derived flavonoids.
Written by Luke Sumpter
Luke has worked as a professional cannabis writer for almost a decade. He specializes in endocannabinoid system science, phytochemistry, and organic cultivation.