TRIMMING

Trimming, sometimes called manicuring, is the preparation of the bud after it has been cut from the plant. How and when buds are trimmed depends on the grower’s goals and strategy. The purpose of trimming is to separate the highest-quality part of the plant, the ripe female flower clusters (buds), from the stems and leaves. Manicuring is one of the final steps in the post-harvest process and is a skilled task that requires training and experience.

Trimming should not be confused with pruning, which is the removal of unwanted vegetation from living plants.

Parts to Be Trimmed

The bud is the plant’s jewel. It is a cluster of flowers that grow at the nodes along and at the tip of each branch. The flowers squeeze tightly between and on top of one another, forming thick layers until the entire group is a dense floral mass, also called an inflorescence or raceme.

More than one bud grows on each branch. If buds grow large enough, they grow into each other, forming one continuous group called a “cola.” Colas are always found on the outer extremity of the branch. The branch may grow at nearly a 90-degree angle to the plant’s stem, although branches of some cultivars grow diagonally or curve up.

Trimming starts with the removal of the buds from the branch (bucking). From that point, the order of the trimming process varies greatly, but to create a fully manicured bud:

The fan leaves are removed.
The “sugar” leaves and petioles surrounding the buds are removed.
Any damaged or contaminated material is removed.

What’s left is the manicured bud. Fan leaves contain small amounts of cannabinoids, and “sugar” leaves contain a larger amount. Both are usually saved for extracts, concentrates, and infused-products manufacturing.

Trimming Styles & Strategies

There are many ways to trim. Style and method depend on quantity and quality of the crop, goals, and individual preferences. The biggest difference is between wet and dry trimming. This refers to the condition of the harvested flowers, whether the material still contains the moisture it had as a living plant or whether it has been dried prior to trimming. The process—whether trimming and then drying, or the reverse—requires preparation. The complexity of planning increases with the size of the crop.

Deleafing is the removal of the large fan leaves before harvesting. This opens up the plant canopy so that light can reach the inner buds, enabling them to grow and ripen faster and develop more potency. Later, harvesting and trimming is easier without the bulky leaves.

In the Field: Wet vs. Dry Trimming

Some growers of large outdoor crops use a combination of wet and dry trimming. They must prepare a temporary space, since it’s used only once or twice a year, and have the time or people to cut and handle the harvest. Meanwhile, the trimmers are wet-trimming as fast as they can. Harvested plants and branches can be kept fresh by keeping them at the same temperature as a vegetable crisper: 38-40°F (3-4°C) and 60% relative humidity or higher. Sometimes available trim labor is overwhelmed, and harvested buds are hung to dry. This can allow for dry trimming to occur later and over a more extended timeline, when trim labor is more readily available.

Trimming is a routine that requires time and space; whether the garden is run by one person or is a large enterprise, space and labor are set aside specifically for trimming tasks.

Wet Trimming

Wet trimming is a sticky, time-consuming process, but generally produces higher potency finished buds. This is because it generally separates a lower percentage of trichomes from the buds than dry trimming. Wet trimming is popular with growers who are not concerned with processing their harvest quickly or have limited space to dry their crop. Trimmed flowers take up less space in the drying room. The process of trimming wet flowers takes longer, but if there is an entire team of people standing by, growers may not have the luxury of waiting for the entire crop to dry.

Pros:

A naked bud takes less time to dry than does a bud surrounded by leaves. This is an advantage if space and time are considerations.
Wet trichomes are more pliant, so fewer snap off.
Wet hand-trimming produces plentiful “finger hash,” hashish that is ready to be smoked soon after it’s removed from workers’ gloves or hands.
The crop is manicured soon after it is cut and is ready for testing and packaging once dried and cured.
Wet-trimmed buds often have a “tidier” appearance than dry-trimmed buds.

Cons:

A bud surrounded by leaves is more protected during the drying process.
Wet hand-trimming is slower than dry trimming.
In surge situations, the size of the crew may need to be temporarily increased to trim the buds before they wilt.

Dry Trimming

Dry trimming is more popular than wet with some producers because it is faster, but dry trichomes are brittle and break off more easily during trimming. Collect them using screens and trays. This powder, called kief, can be smoked, sprinkled over smokable flowers and into joints, pressed into hash, or used for processing into extracts and infused products. (See Processing.)

Pros:

Dry trimming is faster and easier than wet trimming. In addition to using scissors, gloved hands can simply snap off the dried brittle leaves.
Surge harvesting is processed more easily, because the only tasks essential to the harvest are to cut the buds, colas, or whole plants and provide them the proper environmental conditions to dry. Buds can be trimmed anytime they are dry. There is no immediate need for large crews working around the clock. A small crew can trim for a longer period after the harvest.

Cons:

Buds allowed to dry on the stems with leaves attached dry more slowly and take up more space than buds manicured wet and dried on screens.
More trichomes are lost to handling. Once the trichomes are dry and become brittle, they separate from buds more easily.

Trimming Tips

Separate the processes of deleafing, bucking (removing the buds), sorting, and trimming. This maximizes efficiency. Personnel can be switched between activities as needed.
Break the colas along their natural structure and reduce them to buds with no stems sticking out. Buds should be no bigger than 3-4 inches (7-10 cm) in length.
Holding the stem, roll the bud in the hand to best angle it into the blades before cutting.
Look for mold or mildew. Diseased leaves are a sign of infection. The biggest, densest, and often most beautiful buds are most susceptible to mold.

Setting Up the Hand-Trim Station

Light each workstation with bright, non-glaring light.
Install a clean table and adjustable-height chairs that comfortably place trimmers over the table or use a trimming tray that sits on the lap.
Use comfortable chairs compatible with the job. They should help the operator face forward toward the work.
Loud noise and interruptions disturb the workflow. The space should be fairly quiet, except for music, talk radio, or recordings that all can agree on. If that’s not possible, individuals should use earbuds.
The space should be kept neat.
Sweep and vacuum floors and sanitize surfaces frequently.
Use carbon filters and air cleaners to keep the air dust-free.
Trimmers should wear clean clothes and practice proper hygiene such as showering and handwashing. Shower space with clean towels should be available. Inform smelly people to clean up.
Provide appropriate work gloves and hairnets.

How to Hand Trim

Use gloves at all times. Trimmers should take care not to touch their eyes and face. Cannabis is nontoxic, but sticky trichomes sting the eyes and may cause skin irritation.
Place a screen under the trimming area to collect trichomes. Trichomes fall off constantly during handling. Capture them using framed stainless steel mesh or silk screen. Prefabricated screens are available online or are easily made with a 100-micron-thick mesh fastened to a frame.
Disinfect transport bins and tools with hydrogen peroxide, alcohol, bleach, and hypochlorous acid. This helps prevent proliferation of bacteria and viruses.
Arrange separate bins for top buds, high mid-grade, less desirable buds, extractable material, and trash. The other material will be used for processing.
Clip off the smaller buds (also called larf or popcorn). Place them in their own bin.
Trim off the smaller, multifingered “sugar leaves” surrounding the buds.
The bud should now appear almost naked, except for some half-cut leaves sticking out from between the flowers. Watch out for buds that are much bigger than the others. They take longer to finish drying and are more susceptible to mold. They can be dried separately or broken down into smaller buds.
Collect trichomes from the table or trim bin.
Scrape finger hash from scissors.
Clean up.

Useful Trimming Tips

Chairs, Tables & Trays

Chairs and tables affect productivity. View the chair and table as a unit. The chair should be adjustable in height as well as position so that the trimmer’s back and shoulders are not hunched over and the arms are at a comfortable height, allowing the hands full mobility. Resin or plastic garden chairs do the exact opposite. Both the seat and the back force the body backward rather than toward the work. Office chairs used by typists are good choices. A jeweler’s station is an ideal work area. Chairs made for handwork position the trimmer in a more comfortable, forward position. Lap trim trays are very popular because the operator can sit in a comfortable position with arms vertical from the shoulders rather than splayed out over a table. Trays work well but probably are not as efficient as a good chair-table unit.

Keep Blades Clean

With heavy use, trimming shears and scissors become sticky with plant resins. Trimmers use a variety of around-the-house substances to keep blades clear, including commercial products, isopropyl alcohol, vegetable oils, and pH Up. Keep cups near scissors to soak them or dip them to scrub off the excess hash. Seventy percent isopropyl alcohol (IPA) is a better antimicrobial solution than 99% IPA. The higher concentration of water in the 70% IPA helps catalyze the antimicrobial activity of the alcohol. However, 91% and 99% IPA solutions are better for removing resin from trimming scissors.

Trimming tools should be used only for trimming, as opposed to cloning or pruning, in order to prevent the spread of plant-borne infections.

Best Practices

Hiring Workers

Hire and schedule trimmers. Use personal references and interview trimmers about their relevant experience. Always test the trimmer. Inefficient and negligent trimmers can ruin high-grade cannabis flowers and cost far more than they are worth. Slow trimmers slow the pace of production of faster trimmers who often adjust to a slower pace.

Safety & Comfort

The health and safety of workers is the grower’s responsibility. Long-term repetitive work, such as hand trimming, can lead to repetitive stress injuries. It is imperative that trim stations be ergonomic and meet OSHA standards.

Wear gloves, work clothes, appropriate footwear, and goggles when using power equipment. When working near noisy equipment, wear noise filters or headphones that block noise but allow communication with mics and speakers.

Long hair should always be tied back and, along with facial hair, covered with a hat or hair net.

The best lighting sources to use are filtered sunlight coming through windows, skylights, or greenhouses; overhead LEDs or fluorescent lights with a color of about 5,000 kelvin (very similar to sunlight); or table, floor, reading, or workstation lamps that direct light onto the stage where the work is taking place.

Workers should take a break every two hours or less and not skip bathroom breaks or meals. Water and other hydration should be available and close by at all times.

All drinking water should be certified potable water.

Injuries from repetitive stress lead to chronic pain and permanent damage. Anyone who feels significant muscle stress or fatigue should be relieved of duty before they strain their muscles or sustain a more significant injury.

Worker Health

Anyone on the job who develops an allergic reaction to any part of the plant or its dust should not work on the site. An individual’s health is worth more than a paycheck.

The most typical allergic reactions that are expressed physically are bumps or rashes, flushing, and a hoarse voice. Much rarer symptoms that need emergency treatment are trouble breathing, feeling lightheaded, or fainting. These symptoms are external manifestations of inflammation and/or anaphylaxis. Internally other body parts, including organs, may also be affected.

Trim Temperature

Trimming should be done at a clean, climate-controlled, comfortable trimming station. Keep the temperature at 65-70°F (18-21°C) to prevent terpene volatilization. Maintain humidity at about 55-60%. Workers might feel chilled—provide sweatshirts of different sizes.

Some growers choose to trim outdoors. Trim when the temperature is cool rather than hot and with little wind so that the buds aren’t contaminated with dust. Don’t leave plants, buds, or trim in direct sunlight, which rapidly degrades cannabinoids. Use micro-emitters to cool the area, and keep dust down by spraying dry soil.

Varieties of Trimmers & Clippers

Bonsai Pruner, Bud and Leaf Trimmer

Squeezer steel scissors made before 74 CE have been recovered from Pompeii. The metal had to be tempered because they were meant to be pushed in and then returned to the open position. This is a modern version manufactured in 2016. It is just four inches (10 cm) long, with razor-sharp stainless steel blades, spring action, and a delicate handle.

Wiss Clips

The Wiss Clip is a 4.75-inch (12 cm) stainless steel scissor with sharp point blades that are replaceable. It has spring action and a heavy-duty contoured design with industrial PVC plastic handles.

Fiskars

Fiskars have a spring-action, symmetrical, soft-grip handle that works with right- and left-handed users. These are the most popular hand-trimming scissors.

Chicamasa Curved Blade Sap-Resistant Garden Scissors

These scissors are made of the highest-quality stainless steel, with a true curved blade and sap-resistant Florin coating to prevent buildup.

Handheld Machine Trimmers

Electric scissors save hands, wrists, and arms from repetitive stress while maintaining much of the control and the gentleness of hand trimming. About a dozen different types of electrical scissors and clippers are on the market.

Advantages:

Saves hands
Doesn’t tire
Prevents repetitive injuries
Faster

Disadvantages:

There is a learning curve. Training is required.
May not be as thorough as a hand trim.
Machine trimmers require slightly more maintenance than scissors.
The up-front cost is higher than for manual scissors.

Bucking Machines

Bucking machines automate the process of removing buds from the stock. They can increase productivity by about 50%—some bucking machines can process up to 150 pounds (68 kg) of material per hour. To use a bucking machine, insert the cut end of a branch into the appropriately sized hole. As soon as the branch is inserted, the bucker grabs it and pulls it through the machine, stripping the buds from the stock. Bucking machines have variable speeds to process either wet or dry material. The machine can typically be cleaned with an alcohol spray or a heated pressure washer.

To maintain high-quality flower while bucking wet, two factors need to be managed, temperature and freshness. When it comes to temperature, the cooler the better. Indoor growers may consider turning the lights off and the air conditioning up in the garden the day before harvest. For outdoor growers, avoid harvesting in the middle of the day; try to harvest early in the morning when temperatures are cooler.

When wet bucking, it’s very important that the cannabis be as fresh as possible. Cannabis that sits too long between the chop and the bucking machine and has started to wilt can be damaged by the bucking machine. Freshness allows the buds to remain stiff and pop off the stem better as opposed to getting smashed.

The two most important factors for good results while dry bucking is the moisture content of the cannabis and the speed of the machine. The machine should be operated slower, typically the first third of the speed range. When overly dried plants are bucked using a machine, flowers will crumble and fall apart. The big stems and the little stems still need to be pliable so that they can fold, go through the machine, and get stripped.

Mechanize & Automate

Manicuring is a skilled but tedious task. Outdoors it is seasonal, creating bulges in demand for labor for several months. Indoors, full-time, it is monotonous. In a high-powered, automated production system, hand manicuring is expensive and labor intensive. Professional manicurists can trim one to three pounds (0.5-1.5 kg) wet or two to four pounds (1-1.8 kg) dry in an eight-hour workday, depending on cultivar, bud size and shape, and desired trim style. Trim machines can process many times that and are quickly changing the economics of this stage of cannabis processing.

When the first machines were released, cultivators faced the decision of using a machine that simplified processing and saved time and labor at the expense of some cosmetic loss. This is no longer as much of a consideration because newer models are gentler on the buds. Even the gentlest machine trim will result in some trichome loss on the surface of the bud; it’s just a matter of how much. Remember, even the best human trimmers also lose surface glands.

Why Machine Trim?

Machine trimming is most efficient for processing commercial and larger-scale gardens. They can be used for all grades of flowers, including top shelf.

Some machines handle top-shelf flowers better than all but the best hand trimmers. Machine trimming has been overly maligned, especially when taking into consideration that the work of human trimmers varies in both quantity and quality. Many trimmers do a lower-quality trim at a far higher cost than a good machine. Even the best human trimmer tires after several hours, let alone several days or weeks on the job. By contrast, a well-maintained machine treats the millionth bud as nicely as the first.

Tight buds are the best candidates for automatic processing machines. The most common type of trimming machines are tumblers, which come in many models. The new models are very gentle and can trim even top-shelf material. The pitch or angle is adjustable, slowing or speeding up the pace at which the buds tumble through the machine. Spending less time in the machine results in a “looser” trim, leaving on more of the tight trim leaf around the bud. Touch-up trimming is sometimes required, but the bud retains more of its trichomes with a loose trim. Automated trimming machines allow for quicker processing in the stage of cannabis production that requires the most labor and attention.

Automating the manicuring of smaller or looser buds is best done using tools that assist the hand trimmer and are mostly operated electrically but are manually controlled. These tools use the operator’s skill but eliminate the tediousness of scissors.

The space and time savings of trimming wet with machines adds up quickly. Plants can be cut down with power tools and trimmed faster with machine trimmers than is possible by hand. Trimmers are usually designed to cut either wet or dry buds, although a few can process both. Before choosing, make a basic harvest plan.

The downside of machine trimming dried buds is that the buds are brittle, so trichomes snap off easily when manipulated. Dry trimmers are designed to capture trichomes that break off. Several different designs are available, including tumblers and grill or slider models that don’t move the buds around as much. Dry-trim machine advocates say that buds trimmed fully dry both smell and taste better than buds trimmed wet.

State regulations set thresholds on microbiological contamination of cannabis flowers and other products. Wet machine trimming may increase the likelihood of contamination because bacteria counts can build up in wet trimmers that are not cleaned and decontaminated regularly. Contamination spreads easily when the buds come in contact with bacteria. This is much less likely to happen when buds are trimmed dry or when machines are properly sanitized between each harvest batch.

Choosing the Right Machine

Aside from wet versus dry trimming capability, there are other ways to differentiate machines.

Does the device assist the hand trimmer, or does it do the work?
Will the buds be cut wet or dry? Grill-style trimmers are used for dry buds. The grill slides back and forth, opening and closing; this movement catches and cuts the leaves from the bud, leaving them trimmed without much agitation. Trim bags are designed for use with dried buds. These are cloth tumblers that are shaken. The tumble gently agitates the leaves, causing them to break away from the buds.
How many workers does the device need? The tumbler and spinner machines for wet buds do the trimming, and the operators attend to the machine, feeding it and removing finished product. The amount of production from these machines depends on the number of workers operating it.

Return on Investment

Some people see a large price tag on a machine trimmer and are put off. One successful grower wrote: “Don’t think in dollars; think in pounds. A $3,000 machine is worth a few pounds of top shelf trimmed buds and does the daily work of a team of hand trimmers. In just the first day of using the trimmer it more than paid for itself as compared to using manual trimmers.”

The Plant’s Role in Effective Machine Trimming

The plant’s shape, density, and moisture levels affect machines’ performance. Dense buds sustain less damage than light, airy buds that have lots of peaks and valleys, or undeveloped larf buds.

Slow the machine’s speed to trim airy buds. Dense buds with prominent sugar leaves can be trimmed at a faster speed without damage. The size of the load the machine is fed affects the trim. Test to see how large a load the trimmer can handle without overloading and damaging buds.

Machine Trimming Tips

Remove excessive stems and twigs before wet or dry trimming. Break apart big and asymmetrical buds.
Hang-dry plants destined for dry machine trimming. If they are dried on trays or screens, they should be turned every other day or they can flatten out, making it difficult for machines to process.
Not all varieties or all types of bud from a single cultivar are suitable for a single trimming machine. Loose, airy sativas are not as compatible with some models as dense indicas and indica hybrids.

Unlike the trimmer assist machines, which increase the speed that the trimmers are able to process buds with tumblers and grates, the processing speed is determined largely by the number of people attending to the machine. Aside from bucking, in which the buds are removed from the stem, up to five people can attend to the machine, so the tumbler or grate is constantly processing. With fewer people, the machine may run empty, lessening its efficiency.

Using Small Dry Trimming Machines

This tumbler trimmer method requires a team of one to five people. With each added person the efficiency increases because the machine is working a greater percentage of the time.

The branches or colas are cut from the plants and placed in bins.
The buds are removed from the branches using a bucking machine and fall into another basket.
The bins are transported to a room cooled to 40-45°F (4-7°C), where they are stored.
Buds are fed into the tumbler and fall into a waiting basket.
The basket is taken into the drying room, and the buds are placed on trays or screen racks.

Tips

Wet trim before the flowers begin to wilt and lose their turgidity.
Dry trim at 10-16% moisture, no more or less. Common moisture meters help ascertain the approximate dampness of buds. Using moisture meters requires a learning curve and should be used consistently for consistent results.
Optimal feeding speeds vary by variety and environmental conditions. Test speeds and angles for each batch.
Run the machine flat and slowly increase the angle to adjust the throughput speed. Assess the results and determine the best angle for the specific job. Don’t run too steep.

Troubleshooting

Unripe Harvest

If the harvest must be trimmed early in the season, there will be fewer mature, dense buds and a higher proportion of small buds and sugar leaves. If only a small percentage of the buds are grade A and most are loose, not only are they bad candidates for machine trimming because they will get sliced up in the trimmer, but they may not be worth trimming at all. They may be best used for making concentrates.

Lubricants & Anti-sticking Agents

Some trimmers require lubrication of their cutting surfaces and moving parts. Cannabis resin is sticky and easily gums up machines, so some machine-trimmed cannabis will have a tiny amount of residual oil on it. A few trimmers run without oil. Use food-grade oils and minimize their use to avoid contamination.