How to Grow Hemp for CBD in Wisconsin – Step 9: Oil Extraction

The major demand within the current CBD market is based around concentrated oil. Concentrates allow for a variety of different ways to get CBD into your body such as ingestion, topical treatments, and vaporization. The most common form of CBD oil is packaged in tinctures, which is what the following will touch on. There are many different ways to extract CBD and produce tinctures, so I’ll just be covering a rough outline of the method we use at the laboratory that I work in.

Extracting the CBD into a crude oil is the first step to making tinctures. Although there are solvent-less techniques, this is typically done by using solvents such as butane, pentane, hexane, propane, and isopropyl alcohol. When run through a pressurized extraction system, these solvents essentially attach to the flower’s present cannabanoids (CBD), and pull it from the plant matter. There are many factors that processors must confront to pull this off effectively, but going into detail would be an information overload and most likely require a whole separate blog series.

After the CBD infused crude oil is produced, this is ran through a series of distillation techniques involving heat and vacuum pressure to pull the leftover solvent from the product. From there, the refined oil is typically mixed with a high-fat vegetable oil. The fat lipids attach to the CBD molecules and activate them, making the end product safe for human consumption.

How to Grow Hemp for CBD in Wisconsin: Step 7 – Curing

After your hemp seems as dry as possible from the wire hanging described in post #6, it’s time to cure the flower, which ensures the moisture in the buds is fully released. You’ll know it’s time to cure when the small branches break with a snap instead of bending. While some growers overlook the curing process and push their flower straight to processing or wholesale, the most accredited operations use a prolonged curing method for its added benefits. These benefits include increased potency and aroma, along with a longer preservation time of the buds.

The first step to curing your flower is to separate the buds from the branches. After separation, trimming the buds of any leaves and stems will allow for full oxidization of the flower. This is a tedious process, but it’s recommended for any growers looking to produce the highest-quality flower possible. Once your buds are manicured, place them in any airtight storage vessel, such as a canning jar. The flower should be packed loosely to the top. Be sure not to compact any buds before sealing the container.

Trimmers prepare the hemp flower, or bud, to make it more appealing to consumers.

From there, place the containers in a cool, dark, and dry spot and leave them there for around 3-6 weeks on average, although a handful of strains require several months to be fully cured. Throughout the first week you’ll want to open the containers and let them breath for a couple minutes. You should notice your buds (which were crunchy when put into the curing vessel), are now a bit moist due to the reoxygenation. Red flags include the presence of an ammonia-type smell, which suggests bacteria is molding your flower, or overdried buds that are still crunchy. The latter is preferable, as it could still be partially salvaged via oil extraction, which will be discussed in the next post. Stay tuned, and thanks for reading!

How to Grow Hemp for CBD in Wisconsin – Step 5: Harvest

Timing is without a doubt the most crucial factor when harvesting your hemp crop. Growers must let the Wisconsin Department of Agriculture, Trade, and Consumer Protection know when they plan to harvest in advance. The optimal time to harvest is when your plants test high in CBD, yet still under the 0.3% THC threshold allowed by the state. Predicting when this optimal cannabinoid content will take place is a tough task. The following tips can help give you an understanding of calculating the proper date.

Although many farmers simply harvest after a set amount of days since first sprout, the top CBD farmers will track their grow with spreadsheets developed through testing plants along the growth phase. Getting your plants tested on occasion throughout the growing season may take time and energy, but it’s sure worth the reward. The more data you collect on your crop’s CBD and THC content, the easier it will be to predict this optimal date. With some basic algebra, growers can use this data to find the slope, and apply this slope to the calendar. Once the optimal date is determined, contacting the DATCP one month in advance will give them enough notice to have your fields tested prior to this date. It’s a safe bet to pull the harvest date back a week or so once you’ve calculated it, just in case the data is off.  If plants do run “hot”, or over the 0.3% THC limit, the state will force the whole field to be destroyed.

Beyond the harvest date, growers should be prepared for harvest with enough labor and equipment for the size of their fields. If your grow is on the smaller side (10 acres or less), hand cutting the plants at the root with machetes or loppers is your best bet. For large scale operations, some farmers use modified harvesters for crops such as corn to cut the plants off halfway up the stalk. This leaves the bottom half to decompose into the soil and replenishes many of the nutrients used during the grow. I hope this shed some light on the hemp harvesting process, stay on the lookout for the following step in this blog series; Drying.

How to Grow Hemp for CBD in Wisconsin – Step 4: Growing

Once your hemp plants are in the ground and begin to take root, it’s mostly a waiting game until harvest approaches. For crops that were planted with regular seed, identifying and removing male plants is absolutely key for a high-quality harvest. Growers who fail to do so will see an over 40% reduction in cannabinoids (CBD), and the pollinated plants will convert their energy from growing larger and more potent towards producing seeds. Pollinated crops will result in an over 25% loss in biomass, which is all the more reason to plant using feminized genetics.

As stated in earlier posts throughout this series, farmers looking to stay proactive during this time should investigate for any wildlife that may be harming their crop. Zero insecticides, fungicides or pesticides can be used since the chemicals will be converted into the plant’s oil profile and make the flower completely worthless. Insects can be an issue in certain areas, although the majority of Wisconsin growers have seen little threat from these pests so far.

If a drought occurs and there’s no irrigation in place, you should work out some sort of system to keep your plants watered. Stressed plants are proven to yield significantly less than those that aren’t stressed, so the overall goal during the growing phase is to provide as least a stressful environment as realistically possible. Aside from keeping your crop watered, I’d highly suggest investing in weeding equipment such as weed whackers, machetes, clippers, etc. These will be vital to keeping assuring the soil’s nutrients are going strictly to your plants. One common point of feedback from Wisconsin farmers who grew hemp in these past couple years is that it was much more labor than they had anticipated, so be fully prepared to work and/or have extra hands at your disposal.

How to Grow Hemp for CBD in Wisconsin – Step 3: Planting

The third step to growing hemp for CBD in Wisconsin is the planting process. The majority of growers plant sometime throughout early June and late July. A major factor to consider when scheduling a planting date in Wisconsin’s unpredictable climate is the risk of frost. Frost can kill off entire grow operations when plants are extra vulnerable in their earlier growing phases, so it’s a safe bet to get your seeds/clones in the ground a couple days later rather than earlier.

As with any plants, hemp will grow larger and stronger with the more room you space between each plant. The general rule of thumb is to plant seeds/seedlings somewhere between 3-6 feet apart from one another, with each about 0.5” deep in the soil. The closer your plants are to each other, the more plants you’ll have per acre. For example, one acre will grow a rough estimate of 1600-1800 plants when seeds are placed 5 feet apart. Since the hemp industry is so new, there isn’t much equipment made to automate the planting process quite yet. Equipment made for crops such as corn, soybean, etc., can be modified to an extent, but planting by hand is the most reliable method for smaller grows (for now).

Wisconsin wildlife has shown an interest in hemp, so fencing your fields is a solid option to protect your green ladies. Another addition to think about for planting is irrigation. Although our summers in Wisconsin are usually steady when it comes to rain, there have been droughts in the past. Also, it’s not a bad idea to place a tarp over your crop asides from where you place the seeds/seedlings. This will save you countless hours of weeding and assure that your plants have little competition for the soil’s nutrients. Thanks for reading! Be on the lookout soon for Step 4 to Growing Hemp for CBD in Wisconsin; Growing.

How to Grow Hemp for CBD in Wisconsin – Step 2: Genetics

After assuring that your soil is prepared to grow hemp for CBD, the next step is to find the proper genetics to plant. This is arguably the most influential factor towards the overall health and quality of your plants. Good genetics can produce below low-quality flower if grown with carelessness, but below-average genetics are incapable of growing the top-shelf buds we’re all aiming for. The Wisconsin Department of Agriculture, Trade, and Consumer Protection has a list of approved seeds for farmers to choose from.

There are multiple options to consider when choosing genetics, such as unfeminine seed, feminized seed, or clones. While unfeminine seed is the cheapest option, be aware that male plants will sprout and potentially seed out the female plant’s flower, drastically reducing the quality. The following option is to plant strictly feminized seed. Although this is option is nearly twice as expensive as unfeminized seed, it reassures that little to no male plants will be present within the crop. The third and final option is to find a nearby farmer in your area who is selling clones. Clones are a reliable way to find identical genetics that thrive in your area, all the while still maintaining a strictly feminized crop. Growing with clones nearly guarantees a high-quality harvest, but it’s by far the priciest choice with each acre of clones costing around $8,000 plus labor.

When deciding which genetics option to move forward with, you should always investigate who else is planning to grow hemp in your local area and which genetics they’re using. In the case that you were to invest thousands of extra dollars for a feminized option, there’s always a risk that your plants will still be pollinated by males from a different crop in the area via winds or bees. This step in the growing process is key for a quality harvest, which goes to show that planning months before and doing your research is absolutely vital when growing hemp for CBD.

How to Grow Hemp for CBD in Wisconsin – Step 1: Soil

Wisconsin saw a massive breakthrough in 2017 when the federal government passed the 2018 Farm Bill, allowing farmers throughout the country to legally grow and process industrial hemp. While this was a great step forward, relatively inexperienced Wisconsin farmers were faced with the difficult task of learning how to properly grow the crop. This post will be the first of a series in which I’ll try my best to explain the most efficient process of growing hemp in Wisconsin.

First and foremost, farmers must apply for a license to grow through Wisconsin’s Department of Agriculture, Trade, and Consumer Protection (DATCP). More information on licensing can be found through this link. As far as the actual growing, the first step towards farming industrial hemp is to check for adequate soil.

There’s a few requirements the soil should meet if you’re looking to take a hemp crop from average to high quality plants. Hemp thrives in loamy soil that is drained well. The ideal acidity (pH) of the soil is somewhere between 7 and 7.5. Hemp is vulnerable to damage via soil compaction during its first stages of growth, so the less clay in the soil the better.

As for nutrients, hemp responds well to the typical optimal levels of nitrogen, phosphate, phosphorus, and potassium. If your soil is lacking any of these nutrients, it’s suggested to add the lacking element accordingly. One of the biggest struggles hemp farmers deal with is the inability to use chemical fertilizers or herbicides. Since the plant’s cannabidiol (CBD) will be extracted into oil after harvest, hemp must remain fully organic throughout the growing process. It’s encouraged to use organic fertilizers such as cow or chicken manure to fully prepare the soil for the grow. I hope this post educated those who are interested in adding to Wisconsin’s emerging hemp market, feel free to comment with any questions and be on the lookout for the next step’s post in the near future!