What to do with cannabis stems is an expensive problem for industry, but home growers just make more medicine.
What to do with cannabis stems? It’s an important question for a green industry, as cannabis purports to be. Research in the Cannabis Manufacturing Report estimates North America produced one million tons of cannabis and hemp waste in 2019 alone. And all that refuse has to go somewhere.
Unfortunately, stems and stalks are an unavoidable part of cultivating cannabis. You can’t get flowers and seeds without them. But because the waste contains trace amounts of THC, disposing of them isn’t always easy. There are laws that forbid how even legal weed growers must dispose of federally illegal plants.
Some cannabis waste companies and consultants have popped up recently to help growers manage their disposal. However, the question of what to do with cannabis stems still needs a better answer. Especially if the industry wants to grow sustainably and in the right manner.
What Happens to Waste now?
While the cannabis industry aims to keep things as green and eco-conscious as possible, there aren’t always good green options when it comes to cannabis stems and stalks. States and provinces now have regulations in place that pertain to waste disposal and — surprise, surprise — the laws vary between every location. The patchwork of laws means there’s no one easy solution for what to do with cannabis stems.
The regulations are there to ensure that cannabis material doesn’t leak out of large grow houses. Or make its way onto the market in another form. Most laws require detailed record keeping on exactly what happens to every ounce of cannabis waste. Canada and most legalized states in the U.S. have laws about leaving the waste undisturbed for a brief window of time (usually three days) to allow authorities time to inspect it if any problems arise.
But after that time is up, growers can’t just leave their waste out for the garbage truck to haul away. Some companies contract with specialized waste removal services at great expense to drive their stalks and stems to a dump. But that’s not an ideal solution. Organic landfill waste creates literal tons of greenhouses gases. So this process is pricey, time-consuming, and bad for the environment. Unfortunately, it’s usually the easiest.
Leftover cannabis material can be used to make cannabis concentrates, but many growers don’t have the resources or processing abilities to scoop up all their waste and turn it into other products that may or may not sell. Instead of making hefty investments in new technologies, there are other solutions that can be done in cheaper and more eco-friendly ways.
Some states and provinces allow outdoor growers to compost their waste and re-apply it to their fields as a soil strengthener. This requires a composting permit, and usually caps the amount of waste that can be composted. Oregon, for example, limits the number of composted organic material at 100 tons annually per operation and has requirements for the amount of pollution and odor the compost can produce. Hence the need for consultants.
While this is fine for large operations with space for outdoor composting, smaller grow farms need a better solution. Even then, many American grow operations cannot send their material off-site to be composted because the Controlled Substances Act, which governs how those locations handle Schedule I material.
Another suggestion for what to do with cannabis stems is the Bokashi fermentation method. It involves shredding green waste and mixing it with another compostable material in a one-to-one ratio. You then add water and a specialized bacteria activator to the mix. The end result is then locked in an airtight drum for two weeks, during which time it breaks down into a nutrient-rich fertilizer.
The Bokashi method is environmentally sound, but it’s difficult to do well. Denver’s Cannabis Environmental Best Practices Guide warns that using an incorrect amount of activator will corrupt the whole process and cause the cannabis to rot instead of ferment.
Advances in composting and fermentation are big helps when it comes to reducing the carbon footprint of cannabis waste and giving growers options, but a patchwork of ever-changing regulations makes it difficult to find solutions that are replicable on a large scale. And the complexity of the operations mean specialized knowledge is a must.
What to do With Cannabis Stems for Home Growers
There are different options for those who grow their own cannabis at home. That’s great because, as any home grower knows, cultivating cannabis take a long time and the harvested amount of the plant pales in comparison to what’s left behind. Luckily, the regulations that apply to large industrial growers aren’t forced upon backyard operations. However, it’s still not a good idea to toss out your green waste alongside the kitchen garbage.
Instead, consider using the leftover material in new ways. Composting and fermentation options are available, although the latter might be too expensive for a small-time grower. Composting is a better and easier solution, and it allows the leftover plant matter to help the next crop.
Home composting is easy. Simply add your stalks and stems to the compost heap in your backyard and maintain it like any gardener does. Like other plant materials, cannabis leftovers will biodegrade into rich fertilizer. Of course, there are also several ways to consume what the cannabis “waste” for those who want to get the most from their growing.
Waste Not: Turning Stems Into Other Cannabis Products
While stems aren’t great to smoke, they can be decarboxylated and seeped to create a decent (if not always potent) cannabis tea. Likewise, some people use stems to make cannabutter, bubble hash or topical creams. It’s important to remember, however, that stems do not contain much THC or CBD. Some inclined home growers purposefully scrape off the stems and use the result like shake.
Here’s a simple way to produce stem cannabutter. Start with an equal amount of ground up stems and butter (say five grams a piece. Then melt the butter in a pain over low heat. Once it’s melted, shake in the stems and let the mixture cook gently over lower heat for about twenty to thirty minutes. It’s not the most efficient way to get high-quality butter, but it’s easy and it works. And you won’t waste your stems.
Alternatively, running cannabis waste through a woodchipper creates a healthy mulch that can be add nutritional value to your compost pile. Additionally, scattering the mulch over a garden with live soil. This is fine as long as the cannabis plants are healthy — using the stalks of sick plants can spread disease. When growing always try to use all of the plant as even cannabis roots can be made into natural medicines.
For home growers, the options for using leftover stems are good. The industrial solutions need to catch up.